Ferns that spread quickly

Got Fern? Controlling Native Invasive Plants

The author helping out the maple regen on his woodlot.

Exotic invasive plants get the headlines, as they crowd out native species, deprive wildlife of food, and generally devalue the Northern Forest. But in certain cases, native plants can cause the same problems. In fact, on many of the woodlots I see, the native invasive plants are a much bigger problem than the exotic ones.

On my own woodlot, the native plants that have earned the invasive label are ferns (especially hay-scented), striped maple, and American beech. These plants are all indigenous, and they all have a habit of rapidly taking over large areas to the exclusion of other species.

The word “problem” is relative. Clearly, native invasive plants aren’t likely to take over the Northeast, or they would have already done so. Eventually – on the scale of decades or centuries – other species will almost undoubtedly grow on any given site.

Thus, the real problem with native invasive plants is that they conflict with our human desires. Simply put, we want to be growing different plants, whether for monetary, aesthetic, or wildlife reasons, and we want to be doing so now. In a world where property taxes and returns on investment play a role, many forest property owners want to grow valuable trees rather than native invasives. For landowners whose objective is to promote wildlife, having a woodlot that is dominated by plants that are poor food sources or habitat for their desired species will obviously not lead to success. (We should note that mature beech can be of considerable value to wildlife, because of the occasional crops of beechnuts, but many of the root sprouts die of beech bark disease before producing either nuts or merchantable wood.)

We’d likely feel very differently about ferns, striped maple, and beech taking over our woodlots if they produced valuable products. Imagine hay-scented fern or striped maple producing a valuable medicine, with the plants worth as much per pound as ginseng. Then we’d be looking to promote their growth! What if beech, whose prime sawlogs are currently worth little more than firewood, were as valuable as cherry or walnut?

Beech brush rises from a cut stump.

Why so prolific?
Native invasive plants come to dominate a woodlot in many ways. For starters, they’re usually shade-tolerant, and can grow, albeit slowly, in the low light levels found under forest canopies. Once established, they can form dense stands that shade out seedlings of other species. When the canopy is opened up, whether through logging, weather events, or death of overstory trees, the invasive plants in the understory are poised to grow quickly. Some use allelopathy, a form of chemical warfare, whereby the plant produces and disperses chemicals that inhibit the growth of neighboring plants.

People also share some blame for the success of native invasives. Sometimes only the more valuable trees are cut during a harvest, giving beech and striped maple a selective advantage.

Our wildlife policies have also had a profound influence on what plant species grow in our forests. Populations of deer and, to a lesser extent, moose have exploded in the last 100 years. Where populations are high, selective browsing affects the species of trees, shrubs, and herbaceous plants growing on the forest floor. Striped maple and beech are browse of last resort for deer, so seedlings of these trees have a huge advantage over seedlings of trees the deer prefer, such as ash, maple, and oak. My observations also suggest that wild turkeys influence forest composition, as these birds scour the forest floor for the seeds and plants they like.

Now that we’ve identified the problem, the question becomes how to control native invasives. I’ve found that the control effort is a two-part process: first, you have to kill or seriously set back the undesirable plants to make room for more desirable ones; second, you have to promote the establishment and growth of the desirable plants.

Determining what is most likely to succeed, and what is likely to be most cost-effective, requires first assessing what is currently growing on your forest floor. This includes identifying the species, their density, and their condition. An understanding of how this composition arose is useful – what roles did past forestry activities, wildlife, and site conditions play? Current and future factors that influence the composition and growth of the regeneration need to be considered: these might include encroachment by exotic invasive plants, high populations of deer, moose, or other animals in relation to the available food supply, and planned management of the overstory trees. Depending on the situation, a single action may tip the balance in the desired direction or repeated efforts over many years may be needed to realize success.

Favoring the plants you want
In areas where native invasives are not yet dominant, simple forestry practices can help keep the scales tipped in your favor. There are a number of ways to promote and establish the growth of desirable species at the expense of the undesirable ones.

For example, where desirable advanced regeneration is already established, it’s a good idea to perform harvesting operations in winter, preferably with snow cover. Snow helps protect valuable seedlings from damage. Furthermore, when broken off in the dormant season, hardwood seedlings and saplings generally sprout more vigorously than when the same damage occurs during the growing season.

Where good advanced regeneration of desirable species is not present, harvesting without snow cover can help prepare a seedbed. The movement of logs and machines disturbs the upper layers of soil, helping to promote the germination and growth of seedlings. While rarely used in the Northeast, machines designed to scarify the soil can be used to achieve even greater soil disturbance.

Sometimes it’s possible to time harvesting operations with a good seed year to increase the odds that desirable species will be well represented in the next generation of trees. Careful observation of desirable trees that flower in the spring and set seeds in the fall gives a few months notice of a good seed year. White pine gives an extra year of notice: small cones form the first year, with the cones enlarging and maturing in the fall of the next year.

Other ways to favor desirable species include shelterwood cuts, where appropriate, in which roughly half of the forest canopy is removed to allow light in while retaining mature trees as a seed source. You can also encourage deer hunting on your land to help reduce browsing pressure.

In this stand the diseased beech was cut and treated to promote oak regeneration.

Discouraging the plants you don’t want
In cases where native invasive plants already dominate the advanced regeneration, you’re going to have to kill or seriously injure the undesirable plants. This can be accomplished either mechanically or chemically. For a few forest ecosystems found in the Northeast, fire can be added to the list of methods. Consideration needs to be given to whether to kill the plants selectively or on a broad scale – the broad-scale option is preferred when there are so many undesirable plants and so few desirable ones that it makes more sense to kill them all and start over.

The very attributes that make invasive plants invasive make them difficult to control mechanically. They generally resprout vigorously after cutting or mowing, making many treatments at regular intervals necessary for success. Uprooting is hard work, and pieces of root (or rhizomes, in the case of ferns) left behind often sprout and grow new plants. Bulldozing, which may be satisfying at first as a large patch of ground goes from a tangle of green invasive plants to bare earth, is likely to be counterproductive: come back a few years later and the many pieces of plant parts churned into the soil will have sprouted and grown into an even denser tangle of plants.

Oak seedlings rise where the beech fell; the hope is that the slash will provide some protection from deer.

In my woodlot, I tried to control a patch of striped maple by hand pulling over three years. These seedlings ranged from small, two-leaf specimens to knee-high specimens with a dozen or so leaves, and they covered the forest floor, overtopping some northern hardwood seedlings. Every time I passed through this patch (it was a few hundred square feet in size and was on one of my regular walking routes), I stopped and pulled a dozen or more striped maples and placed them on rocks or branches to desiccate and die.

After three years, the striped maple was obviously less dense than when I started, but it kept resprouting, and it was clear I was far from winning the war. I realized that pulling striped maple on the scale of my woodlot would be a Herculean undertaking, and one that I certainly was not up to. In order to effectively control the native invasive plants on my woodlot, I needed a better way. Although I’m reluctant to use chemicals, I’ve found that in some cases, chemical control is the only path to near-term success.

Four methods of chemically killing native invasive plants can be used: injection, cut-stump, basal bark, and foliar. As the terms injection and cut-stump imply, chemicals are injected into the stems or applied onto the just-cut stump of plants to be killed. Fairly concentrated chemicals are used, and these methods are generally most applicable for larger plants. In basal bark treatment, the chemicals are mixed with an oil base and applied around the bark at ground level; the chemicals are absorbed through the bark, eventually killing the plant. Basal bark treatment is most commonly used on large seedlings through sapling-sized plants.

Foliar treatment is done by applying chemicals to the leaves of plants, where they are absorbed and eventually kill the plant. A relatively dilute solution is used. Application can be done by wiping, spraying, or mist blowing. In all cases, enough of the appropriate chemical needs to be applied to each plant under conditions that favor success. Safety precautions are needed to protect people, domestic animals, wildlife, non-target plants, and water supplies.

Over the past several summers, I have been working with a foliar treatment to control striped maple, beech, and ferns (mainly hay-scented) where they dominate the advanced regeneration on my woodlot. I use a five percent solution of glyphosate in a backpack sprayer. This allows me to be very specific, treating the plants I want to kill and only rarely getting chemicals on non-target plants. The foliar treatment method allows me to work with a dilute solution, which effectively treats small plants and gives me a wide window for application, from June through September.

I have found that it is far easier to treat the invasive plants before doing overstory work: there is no slash to wade through, and the target plants are far less vigorous (requiring less chemical) than they will be once the canopy is opened. I find that wetting about 50 percent of the leaf area with the five percent glyphosate solution is sufficient to kill striped maple and beech. Even less of the frond area needs to be wetted to kill the ferns. By avoiding dripping, tree and other plant seedlings that are often present under the target plants aren’t affected by the glyphosate and are released to grow. For striped maple and beech higher than shoulder height, I cut the plants off at ground level, usually in early spring when the ground is too wet for most other forestry activities. In late spring, after they have resprouted, relatively little foliar spray is needed to kill the root system. (As an alternative, I could use the cut-stump method, cutting these small trees any time they are actively growing after full leaf expansion and applying a concentrated glyphosate solution to the stump.)

To date I have treated nearly 100 acres. The kill rate is excellent, and desirable seedlings (both those that were competing with the native invasives and newly established ones) are coming to dominate the forest floor. The early results are very promising, and I am hopeful that the plants on my woodlot will, in the future, be dominated by white pine and northern hardwoods rather than the striped maple, ferns, and sick beech that dominated the advanced regeneration when I started.

Roundup being applied to a cut stump.

As an organic gardener, I was reluctant to use herbicides on my woodlands. It was only after finding that mechanical methods weren’t working that I decided to experiment with chemical control of native invasive plants.

The herbicide glyphosate is widely used to control unwanted vegetation. Glyphosate is the active ingredient in Roundup, the best-known trade name. Since the patent expired, many companies now sell glyphosate under a variety of trade names. It is available in various concentrations, with or without a surfactant, and sometimes in combination with other herbicides. Surfactants reduce the surface tension of water-based solutions, enabling them to do a better job of wetting surfaces, which can increase herbicide absorption.

Glyphosate is a water-soluble salt that works by disrupting an enzyme pathway essential to plants. Since this pathway does not exist in animals, glyphosate is considered relatively safe for humans and wildlife. This is reflected in the minimal personal protective equipment required for workers using glyphosate, though everyone working with the chemical should wear a long-sleeved shirt and pants, chemical-resistant gloves made of waterproof material (I use nitrile gloves), and shoes and socks. In addition to its low toxicity to animals, glyphosate has the advantages of breaking down quickly in soil and not being taken up by plant roots.

When buying herbicide, it is important to pay attention to the concentration and any adjuvants (substances, such as surfactants, added to increase effectiveness.) Much of the glyphosate sold in retail outlets is diluted to such a low concentration that it is not effective on woody plants. It is most economical to buy glyphosate as a concentrate and dilute it prior to use. When working with the concentrate, I wear a face shield to protect my eyes and face in case of any splashing. I also add a dye to the mix so that any splashes or spills can be easily seen.

It takes some time for the effects of foliar glyphosate applications to show. The first symptoms are yellowing and gradual wilting of the leaves, which can go unnoticed for two weeks or more on understory woody plants, especially in cool, cloudy weather. To kill the plant, the chemical needs to be translocated through the plant so that it will kill the roots as well as the foliage. Therefore, if you cut woody plants soon after the leaves wither, the glyphosate may not have sufficiently reached the roots, and the plant may well survive and send up new sprouts. I use a low-pressure spray and adjust the nozzle to give large droplets. This minimizes drift and helps ensure that the herbicide lands only on my targets.

With any herbicide, it is very important to thoroughly read and understand the directions and to follow all use and disposal instructions. Herbicide use is regulated at the state level, so regulations vary from state to state and herbicide to herbicide. In Maine, New Hampshire, New York, and Vermont, landowners are allowed to apply glyphosate on their own land without a license unless there’s an easement on the property that forbids it. However, the rules get more complicated if you’re applying chemicals commercially. In my home state of Vermont, an appropriately licensed pesticide applicator must be present to supervise treatment whenever glyphosate is being used on other people’s land. Other states have their own rules and fine print, so you’ll want to learn all the details before you spray. The National Pesticide Information Center has a website with links to each state’s pesticide regulatory agency at: http://npic.orst.edu/state1.htm

I found the information I learned in becoming a licensed applicator invaluable and urge anyone contemplating the use of herbicides to study the training manuals, even if you don’t need to become licensed. — IRWIN POST

Irwin Post is a forest engineer living in Chester, Vermont.

Gardening How-to Articles

How to Grow Ferns in Your Garden

By Nancy Swell | December 1, 1994

Ferns are a widely varied group of plants. Their native habitats range from the tropics to the Arctic and from deserts to swamps. They may be coarse or delicate, succulent or filmy, crown forming or creeping, lime lovers or lime intolerant, invasive weeds or virtually impossible to cultivate. One of the first plant groups to adapt to life on land, ferns have since adapted to most conditions and environments, but relatively few are able to contend with direct sunlight and low humidity. Most species need moist soil, high humidity and enough shade to maintain these conditions.

Ferns are essentially wildlings; unlike many of the flowering plants, such as herbaceous perennials, they have not been hybridized for garden conditions. Before you begin your fern garden, observe the ferns growing naturally in your area. Most of these are available commercially. Be sure to place them in your garden where conditions are comparable to those supporting the native ferns in the wild. Be cautious in your selection. If a fern’s growth in the wild is rampant, it is likely to be even more so in your garden. If the fern grows only in a specialized habitat, such as moist rock crevices, it may be difficult to grow in the garden. Grow only those plants for which you have the proper conditions. Never collect ferns from the wild. When you buy ferns, look for reputable dealers who state explicitly that their plants are nursery propagated, not collected from the wild. Selected forms with fancy fronds are always nursery propagated.

Choosing Ferns

The section of the country where you live and garden determines to a large extent the plants you can grow. Most of Florida and the southern coastal areas can grow the tropical ferns that the rest of us can cultivate only under glass or as house plants. Southwest gardeners can grow only those that have adapted to less humidity, while gardeners in the midwest, northeast, mid-atlantic and upper south can grow most woodland types.

Keep in mind, too, that some ferns have specialized requirements. It’s not impossible to grow maidenhairs, hart’s tongues or other ferns that prefer an alkaline soil, even if your soil tends toward the acidic; mixing crushed limestone, oyster shell grit or cement rubble in the soil will provide a constant source of lime and improve drainage. If you live in a limestone area and want to grow those that require acid conditions, it is not quite so easy. You can make the planting bed acidic by working lots of peat or humus into the soil, separating it from the subsoil with landscape fabric or a two-inch layer of granite grit and treating the soil with sulfur or ammonium nitrate. The problem is that the water in these areas is likely to be alkaline, and will gradually change the pH of the soil. Under these conditions, it’s best to grow ferns that prefer limestone, or those tolerant of alkaline conditions. Most adiantums, aspleniums, polystichums, dryopteris and athyriums will grow in a wide pH range, and the organic material in a well prepared soil will help to buffer the effect of excess acidity or alkalinity.

Many ferns have a natural affinity for rocks. Some, such as polypodies and the walking fern will actually grow on the rock surface; others, such as Cheilanthes and the cliff brakes, need exceptionally sharp drainage and more sun. Almost all appreciate the protection of rocks, which help the soil retain moisture and establish a microclimate that is warmer in winter and cooler in summer than the surrounding environment. It’s important to know which ferns must have limestone and which require acid conditions. Sandstone and granite rocks are generally the foundation for those needing acid, while limestone or even cement rubble will provide alkalinity. Ferns among rocks should be planted in a well drained but moisture-retentive soil.

Woodland Ferns

For gardeners in most regions of the country, species adapted to woodland environments are attractive and easy to grow. In most areas, Christmas or sword ferns (Polystichum spp.), lady ferns (Athyrium spp.) and shield ferns (Dryopteris spp.) are commonly found in the wild. These genera contain other non-native species that will grow under similar conditions in the garden. Most prefer a slightly acidic soil with 50 to 75 percent humus, good water retention and excellent drainage.To add humus to your soil, work about 4 inches of coarse compost, rotted manure or fine pine bark into the top 4 to 6 inches. All ferns require ample moisture for growth, as well as a certain amount of humidity to prevent dehydration of their foliage. Established plants of most woodland species are tolerant of periodic dry spells, but that doesn’t mean they will survive bone-dry conditions. Only a very few are adapted to life in bogs or really wet conditions. Swamp, bog and streamside ferns such as the osmundas require more water than most woodland ferns.

Woodland ferns do best in high or dappled shade. The open shade of mature trees or the north side of the house or a wall, open to the sky, provide nearly ideal light conditions. Most woodland ferns will adapt to relatively low light levels, but no ferns thrive in deep shade. Evergreen species are the most tolerant of low light levels. Generally, plants will tolerate more sun and less water in the northern part of their range. The stronger the sun, the greater the need for water; conversely, the more water available, the more sun they will take.

The nutritional needs of ferns are generally met with compost or the breakdown of leaves. Small size and slow growth are more likely to be caused by limited water than lack of food. In fact, ferns are sensitive to excess fertilizer; quick-release inorganic fertilizers are likely to burn the roots. If supplemental feeding is needed, use well rotted manure, fish emulsion or other slow-release organic food. Wind protection prevents the breakage of brittle fronds and reduces dehydration. While shelter is an advantage, the lowest, most sheltered spot is also probably a frost pocket which can delay spring growth, and result in early and late frost damage to deciduous ferns and winter-kill of species with borderline hardiness.

Planting Ferns

The best time to plant varies according to geographic location. Spring planting is preferable where winters are cold and wet. If ferns are planted late in the season in these areas, the roots could very well rot before they are established. Alternate freezing and thawing may heave the rhizomes from the soil, breaking young roots and exposing them, making them prone to desiccation. In warmer climates, fall planting is preferable because the plant has time to establish itself before the stresses of summer heat and drought. If you move or plant a fern that is actively growing, cut the fronds back by half to reduce stress from water loss and help it get established. New fronds usually will be produced as soon as the plant has enough roots to support them.

To move a fern, dig a generous root ball, especially if the plant is in active growth. Next, dig a hole the same depth as the root ball and place the plant in the hole, water well, fill in the sides with good soil and firm the soil around the plant. If the job is well done, the fern may never know it has been moved.

Many ferns available for sale are grown in quart size or larger pots. These are either mature size or will grow to maturity in a year or two.To plant a potted fern, knock the plant out of the pot and gently shake or tease the roots apart. It is important to remove excess potting soil, especially if it differs significantly from the soil in your garden. Potting soils are often light and peaty and will dry out faster than the surrounding soil. This may leave the newly planted fern dry and wilted even though the surrounding soil is moist. To rectify the situation, spread out the roots, mix some of the potting soil into the root area, water well and fill in the planting hole with good soil. Keep newly planted ferns well watered for the first growing season while they are becoming established.

Never let plants growing in 4-inch or smaller pots dry out until they reach a mature size and are well established. Plant them in well prepared soil in a protected area. It is often easier to pot them up for special care. Add fine pine bark to any good potting mix to improve drainage. Do not feed until they are growing well. If the fern requires alkaline conditions, you can add a tablespoon of ground limestone to a gallon of planting mix.

Ferns sold by mail may have been removed from their pots and put in plastic bags or they may be almost bare rooted. When you unpack the plants make sure that the growing tip has not been damaged during shipping. If it has been broken or has rotted, the fern will probably not recover and the shipper should be notified immediately. Depending on size, either pot the fern or plant it in a protected spot and keep it well watered until it has had a chance to establish itself. If the roots seem at all dry, set the plant in water for one to two hours while you are preparing the planting area.

Some ferns may be purchased as small bare rooted plants packed in dry peat moss in a plastic bag. In theory, there is enough humidity in the bag to prevent desiccation of the plant; in practice, ferns do not appreciate being bare rooted, and while they will certainly rot if they are enclosed with wet peat, they are generally dry enough to need a recovery period. Unless you can actually see signs of active growth such as a crozier beginning to uncurl, bare rooted plants are best avoided. Often the growing tip has been damaged by handling, or the peat has become completely dry. If you do try ferns sold this way, soak them in water for a couple of hours and pot them using a good, well draining potting mix. Be careful to keep the growing tips at or above soil level. Keep well watered and transplant to the garden after they have become established. Another disadvantage of ferns sold bare root is that they are frequently dug up from the wild.

How far apart should you plant your ferns? Spacing depends on form, size and type of growth. Crown formers with upright rhizomes and vase-shaped form spread slowly and show to best advantage as a single crown. Goldie’s fern and some of the larger growing polystichums and osmundas may need three feet or more between plants. Oak and beech ferns spread quickly and can be planted fairly far apart. Hay-scented, New York and Virginia chain fern are even more rampant spreaders, and the ostrich fern, which spreads by far-ranging runners, is best planted in an area where it can be controlled.

Growing Tips

Both fern fronds and roots grow directly from the stem, which is also known as the rhizome. All new growth is produced at the stem tip, and if it is damaged the entire plant may be killed. The roots grow at the base of the fronds, or on the lower side of creeping rhizomes. In all ferns they are close to the surface and easily disturbed.

Upright-growing rhizomes form a distinct crown consisting of the tightly coiled croziers at the soil surface, which grow in spring into a whorl of fronds that radiate from the center like a vase. These may grow out of the ground to form small trunks. The roots that grow at the base of the fronds are then exposed to the air and can dry out. If crowns lift themselves out of the soil they need to be replanted to return them to soil level. Adding one to two inches of mulch each year may make replanting unnecessary.

Rakes, hoes and feet do not belong in the fern garden. Surface roots, tightly coiled croziers and developing fiddleheads are too easily damaged. Leave a place to walk, and remove by hand winter-burned evergreen fronds and any other garden debris before the fiddleheads begin to unfurl in spring.

Caring for Ferns

If you choose plants suited to your growing conditions and practice good gardening hygiene, removing debris that may harbor pests, you may seldom have to deal with diseases or pests. Slugs and snails tend to be the most common problems; they are voracious eaters that thrive under the same conditions as ferns. Slug baits containing metaldehyde are effective, but they are toxic and especially hazardous to children and pets. Various nontoxic baits and traps are safer: Dishes of beer sunk to soil level are effective. Slugs will also collect under overturned grapefruit shells and can then be dropped into denatured alcohol for the coup de grace. Ferns are quite sensitive to insecticides. If you must use a chemical poison, test it on a few plants. Avoid the liquid emulsion sprays, as they contain oils that damage ferns. Use dusts or sprays made from wettable powders, reducing the recommended dosage by one half.

To prevent disease, start with healthy plants. Keep the crown of the plant above the soil, and don’t cover it with mulch. Avoid overwatering and space the plants far enough apart for adequate air circulation. Mulching with fine pine bark, pine needles or a fairly coarse compost will help keep the soil moist, prevent weeds or at least make them easier to pull and provide essentially all the nutrients your ferns need. Replenish the mulch each year to compensate for the tendency of certain athyriums or dryopteris to raise their crowns above soil level.

Which Ferns Are for You?

    Ferns for Beginners

    • Adiantum pedatum
    • Athyrium filix-femina
    • Blechnum spicant
    • Cyrtomium species
    • Cystopteris species
    • Deparia acrostichoides
    • Dryopteris dilatata
    • Dryopteris erythrosora
    • Dryopteris expansa
    • Dryopteris filix-mas
    • Dryopteris marginalis
    • Matteuccia struthiopteris
    • Polystichum acrostichoides
    • Polystichum munitum
    • Polystichum setiferum
    • Thelypteris noveboracensis

    Ferns for Sun

    • Athyrium filix-femina
    • Dennstaedtia punctilobula
    • Dryopteris filix-mas
    • Dryopteris ludoviciana
    • Matteuccia struthiopteris
    • Onoclea sensibilis
    • Osmunda cinnamomea
    • Osmunda regalis
    • Polystichum setiferum
    • Sphaeropteris cooperi
    • Thelypteris kunthii
    • Woodwardia virginica

    Ferns for Deep Shade

    • Asplenium rhizophyllum
    • Blechnum spicant
    • Cyrtomium falcatum
    • Dryopteris (evergreen species)
    • Gymnocarpium species
    • Osmunda cinnamomea
    • Polystichum species
    • Phegopteris species
    • Woodwardia areolata

    Ferns for Wet Soils

    • Athyrium filix-femina
    • Blechnum serrulatum
    • Dryopteris celsa
    • Dryopteris ludoviciana
    • Macrothelypteris torresiana
    • Onoclea sensibilis
    • Osmunda cinnamomea
    • Osmunda regalis
    • Thelypteris kunthii
    • Thelypteris palustris
    • Woodwardia species

    Ferns for Dry Soil

    • Asplenium platyneuron
    • Blechnum penna-marina
    • Cystopteris bulbifera
    • Dennstaedtia punctilobula
    • Dryopteris filix-mas
    • Dryopteris intermedia
    • Dryopteris marginalis
    • Osmunda claytoniana
    • Pentagramma triangularis
    • Polypodium species
    • Polystichum species
    • Phegopteris hexagonoptera
    • Woodsia obtusa

    Ferns for Alkaline Soils

    • Adiantum species
    • Asplenium (most species)
    • Cystopteris bulbifera
    • Diplazium pycnocarpon
    • Dryopteris carthusiana
    • Dryopteris dilatata
    • Dryopteris expansa
    • Gymnocarpium robertianum
    • Matteuccia struthiopteris
    • Osmunda claytoniana
    • Polystichum aculeatum
    • Thelypteris palustris

    Ferns for Strongly Acidic Soils

    • Asplenium platyneuron
    • Blechnum species
    • Cyrtomium species
    • Dennstaedtia punctilobula
    • Dryopteris campyloptera
    • Dryopteris cycadina
    • Dryopteris ludoviciana
    • Gymnocarpium dryopteris
    • Osmunda cinnamomea
    • Osmunda regalis
    • Polypodium species
    • Polystichum species
    • Phegopteris connectilis
    • Thelypteris species
    • Woodsia obtusa
    • Woodwardia species

Nancy Swell grows and propagates a wide variety of hardy ferns in her garden in Richmond, Virginia. She is an active member of The American Fern Society, The British Pteridological Society and The Hardy Fern Foundation and is a self-proclaimed fern fernatic.

Make More Ferns by Sprouting Spores

There are a couple of ways to make more of the ferns in your garden. You can wait for them to grow (some spread faster than others) and divide them. Or collect and sprout their spores.

Spores are like little seeds, though they’re much smaller and slower to germinate and grow. They’re found on the fern fronds instead of a seed pod, capsule, or fruit. Spores appear as little bumps, often black or brown, lining the underside of some fronds.

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Step 1: Gather the Spores To collect spores, place a mature fern frond on a piece of smooth white paper. The ripened spores will fall from the frond and onto the paper after several days.

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Step 2: Plant the Spores Carefully fold the paper so the fern spores fall into the crease. Then sparsely sprinkle the spores over moist seed-starting mix. Mist the seed-starting mix with water after planting.

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Step 3: Be Patient Cover the container with clear plastic after planting to keep the spores humid. Make sure the spores stay moist, but not saturated or soggy. Be patient. Spores can take several months to sprout.

Step 4: Plant the New Ferns Once the spores have sprouted, keep them humid until they’re large enough to transplant. For most ferns, this is after they have at least three fronds.

Photo by Holly A. Heyser

I eat a known carcinogen every spring. But then again, chances are, so do you.

Few wild plants are as polarizing as bracken fern, Pteridium aquilinum. It is a global species, living everywhere but the harshest deserts and the coldest tundra. Here in California, it is ubiquitous. I find its fiddleheads — odd looking fiddleheads, like an eagle’s clenched talon — in Point Reyes as early as late February and as late as mid-June in the High Sierra.

That means if you wanted, you could eat bracken fern fiddleheads for four straight months here in California. You could, but you shouldn’t.

Bracken fern does indeed contain a carcinogen, that much is clear. It also contains an enzyme that makes Vitamin B1 less available to the body, so chronic consumption of bracken can lead to nastiness like beriberi. I’ve spent a lot of time over the years reading scientific papers with names like “Induction of Tumors in ACI Rats Given a Diet Containing Ptaquiloside, a Bracken Carcinogen.”

Breezy reading, this. But the slog has been worth it, if only because I refuse to trust the internet and my fellow foraging writers outright. Bracken is so controversial you will see them writing statements ranging from “eat it as much as you want, it’s fine,” to “never, ever, ever eat bracken, raw or cooked.”

And like most black-and-white statements, both are wrong.

After a pretty exhaustive — and exhausting — survey of the literature, it seems pretty clear that a typical forager’s diet of bracken fiddleheads, blanched and sauteed with lots of butter (or whatever) is perfectly safe. Before you start shouting at me, let me explain.

The primary villain lurking within bracken fern is a substance called ptaquiloside. It is, by all accounts, nasty stuff. And bracken fiddleheads are packed with it, up to 0.8 percent by dry weight, according to some studies. But therein lies the first caveat: A raft of other studies shows that ptaquiloside levels vary wildly in bracken stands. Some in New Zealand were even found with none of the stuff at all. So you really have no idea how much — if any — of the carcinogen lies within your pretty fiddlehead.

It is abundantly clear, however, that if you eat raw bracken fiddleheads in the woods you will probably ingest ptaquiloside. And that’s not good eats.

But ptaquiloside has three properties that are of interest to us:

  • First, it is not actually a carcinogen, according to the latest research. But it is volatile, and likes to react in alkaline environments to create what is now suspected of being the true carcinogen, a substance called dienone. This is why drinking milk from animals that have been eating a lot of fiddlehead fronds is a very bad idea; milk, and the healthy stomach of a ruminant, is basic enough to cause the ptaquiloside to transform into dienone.
  • Second, ptaquiloside is water soluble. That means if you soak bracken fiddleheads in cool water (cool to keep them crunchy), and change that water every so often, you will greatly reduce the level of this nasty substance in the fiddlehead; the Japanese often eat bracken this way.
  • Third, ptaquiloside is notoriously volatile at normal temperatures. The pure stuff degenerates at room temperature, which is why the scientists doing the rat studies store their ptaquiloside at -20° Celsius. Once exposed to boiling temperatures, the carcinogen denatures almost completely. Salt increases this effect.

Photo by Holly A. Heyser

Virtually all the data on the subject link most human health problems associated with bracken fern to exposure to contaminated milk from animals eating bracken, contaminated groundwater near bracken stands, and, in some cases, long-term exposure to bracken spores; so if your yard is covered in bracken fern, you might want to dig most of it up.

What all this means is that a very normal cooking process for fiddleheads — blanching in salty water, then shocking in ice water, then sauteeing — renders the fiddlehead close to harmless.

Note that I say “close to harmless.” Even though most of the research out there suggests that normal human methods of eating bracken, which, incidentally, has been eaten by cultures across the globe since prehistory, denature or render harmless what ptaquiloside exists in a bracken fiddlehead, there is one nagging piece of data out there: There is an apparent link between chronic consumption of bracken and an increased level of throat and gastric cancers in the populations of Korea, Japan and parts of China. Bracken is widely eaten in Korea, Japan and parts of China. And when I mean “widely,” I mean almost every day in some cases. Bracken (gosari) is a classic part of bibimbap, one of the most famous Korean dishes there is.

Most of the research on this has been done by Japanese and Koreans, searching for clues as to why they seem to have high rates of throat and stomach cancer. Apparently there are a kaleidoscope of reasons, and habitual bracken-eating is among them. Like anything, ptaquiloside’s poison is in the dose. According to my reading of the research, the body apparently can process out only so much of the stuff, and constant eating of bracken puts too much in the system, and that’s what causes cancer.

I know what you are saying. Why even mess with this crazy bracken thing? Why even put myself at risk?

Several reasons. First, bracken tastes wonderful, like asparagus, almonds and Tuscan black kale all rolled into one. Second, eating bracken is akin to drinking alcohol: Done responsibly, it is enjoyable and perfectly safe. But just as you would not rationally decide to drink a case of beer every day for a month, you would not rationally choose to eat a big plate of bracken ferns every day during the fiddlehead season.

I choose to eat bracken fiddleheads. How often? Maybe a half-dozen times a year. Eat them once and you will see what all the fuss is about, and make your own decision. Just remember your Aristotle: All Things in Moderation.

If you do pick your own bracken fiddleheads, choose those that are not fully extended. You want them either in the horseshoe bend or at least tightly closed. Remember, the eagle’s talon should be clenched, not open. Do not eat them once their fronds unfurl.

Buttered Bracken Fern

Bracken fern is as tasty eat as it is beautiful, but you need to take some special steps in cooking it to diminish its harmful properties. Once you do this, it is best to just simply cook these pretty things and enjoy their flavor, which is a combination of asparagus, almonds and kale. Truffle butter seemed like a natural choice as a flavoring — regular butter and truffle salt is a good alternative. No truffle products? Just use the best butter you can afford and a nice fancy salt. Splurge! After all, you should only eat bracken a few times a year, so enjoy it! Prep Time1 hr Cook Time10 mins Course: Appetizer Cuisine: American Servings: 4 people Author: Hank Shaw

Ingredients

  • 3/4 to 1 pound young bracken fiddleheads
  • Salt
  • 3 tablespoons truffle butter, or regular butter

Instructions

  • Trim the bracken fiddleheads to an even length. Bring a large pot of water to a boil and add enough salt to make it taste like the sea. Fill a large bowl with ice water. Boil the bracken for 2 minutes, then plunge into the ice water. let them sit in the water for 45 minutes to 1 hour. Discard the water. Pat dry.
  • Heat half the truffle butter in a large saute pan over medium-high heat. Saute the fiddleheads for 4 to 5 minutes, flipping them from time to time. Sprinkle some salt over them. Turn off the heat and add the remaining butter. Swirl to coat the fiddleheads with the butter as it melts. Eat at once.

Foraging Resources

You can find all sorts of tips and tricks on foraging edible wild plants, right here on Hunter Angler Gardener Cook.

What are Bracken Ferns?

Bracken ferns are a group of ferns of the species Pteridium aquilinum and its numerous subspecies. Bracken ferns are found in many parts of the world and can grow especially fast in defrosted areas like at the edge of woodlands and recently abandoned farmlands and pastures and also in sunny slopes. They are found in most continents and under many climates except for desert and arctic climates. They are most commonly found in Europe, North America, Australia and New Zealand and are considered weeds in many other countries. Bracken fern is native to Hong Kong and China, and is mainly found in southern China and in Taiwan in these geographical areas. Its leaves (fronds) have distinctive shape and have rhizomes grown underground.

Consumption of Bracken Ferns

Bracken ferns had been harvested for food and other uses for centuries. It has been reported to be grown commercially in Japan, Canada, Siberia, USA and China for consumption. The bracken fern rhizomes had been used to make bread by Maori natives in New Zealand and in Europe during food shortage. In Japan, young bracken fern leaves (fiddleheads) are reported to be prepared by boiling or by pickling before further preparation. Bracken ferns are known to be a hazard to grazing farm animals as they can cause a number of diseases after ingestion. Chemicals from bracken ferns can also be found in the dairy products the affected animals produced. The Canadian Government had advised people who collected fiddleheads of another species of fern (ostrich fern) for food to clean, cook in generous amount of boiling water or steam till tender before further preparations in order to prevent food poisoning due to improper preparation.

What is the Health Concern?

Numerous chemicals had been isolated from bracken ferns. Of those chemicals, ptaquiloside, a highly water soluble chemical, had aroused much interest as it may have carcinogenic properties. Toxic chemicals were reported to be found in all parts of bracken fern.

A number of animal carcinogenicity studies had been performed by oral administration with dried, processed and components isolated from bracken ferns. In animals studies on mice, rats, guinea pigs, toads except cows, bracken fern caused malignant or benign intestinal tumours, especially in small intestines. It can also cause bladder cancer in rats, guinea pigs and cows. Rats study with bracken fern diet as processed for human consumption had produced intestinal tumours. However, the incident rate is lower than that of unprocessed bracken fern.
The International Agency for Research on Cancer (IARC) had classified, in 1987, bracken fern as “possibly carcinogenic to humans” (Group 2B) due to inadequate evidence for carcinogenicity to humans but sufficient evidence for carcinogenicity to animals

How to Reduce the Risk?

With reference to the above findings and that bracken ferns are not commonly consumed in Hong Kong, we have the following recommendations to consumers:

  • Avoid overindulgence in bracken fern products.
  • Proper processing and preparation is essential in order to reduce the level of harmful chemicals in bracken fern. For example, boil the fiddleheads in large amount of boiling water for 15 minutes or steam the fiddleheads for 10 to 12 minutes or until tender and discard the water before further cooking can help to lower the level of water soluble toxic chemicals in the fiddleheads.
  • The public is advised to maintain a balanced diet so as to avoid excessive exposure to natural toxins and contaminants in general from a small range of food items.


Young leaves of bracken fern (Pteridium aquilinum) Photo by ©Al Schneider, www.swcoloradowildflowers.com

Risk Assessment Section
Centre for Food Safety
August 2014

10 ferns to grow

1

Adiantum venustum

This evergreen Himalayan maidenhair fern, Adiantum venustum, does well in shade or dappled shade; its delicate, light green fronds darken with age. Protect from wind. Height: 22-38cm

Delicate fronds of the Himalayan maidenhair fern 2

Asplenium scolopendrium

You often see British native Asplenium scolopendrium growing wild – if you spot it in your local area, it will probably grow well in your garden. It’s evergreen, and needs very little care – just a little tidying in spring. Height: 45-60cm

Glossy, strong leaves of Asplenium scolopendrium 3

Asplenium scolopendrium Crispum Group

A cultivar of Asplenium scolopendrium, Crispum Group is an eye-catching evergreen that has distinctive wavy edges that become more pronounced as the plant matures. Height: 30-60cm

Crinkley-edged leaves of Asplenium scolopendrium, Crispum Group 4

Athyrium niponicum

Deciduous painted Japanese fern Athyrium niponicum is flushed with silver and burgundy, making it an unusual, eye-catching choice. It’s growth is more prostrate than upright; it likes moisture. There are several pretty cultivars. Height: 30-38cm

Delicate, silver and burgundy leaves of the painted Japanese fern 5

Dryopteris erythrosora

Known as the autumn fern, Dryopteris erythrosora is an unusual fern has red new growth in spring, which eventually turns bronze and then green. It’s evergreen and just needs a little tidying up in early spring. Height: 60cm

Bronze fronds of the autumn fern 6

Dryopteris wallichiana

In spring, deciduous fern Dryopteris wallichiana unfurls to produce striking fronds that are 90cm high. If you have the space, it looks particularly effective planted in a group. Height: 90cm

Tall fronds of Dryopteris wallichiana 7

Matteuccia struthiopteris

The shuttlecock fern, or ostrich fern Matteuccia struthiopteris is not a British native, but has naturalised in parts of Britain. It sends up bright green ‘shuttlecocks’ in early spring and develops into a handsome plant. It prefers a moist soil. Height: 1-1.5m

Bright-green fronds of the shuttlecock or ostrich fern 8

Onychium japonicum

This delicate fern, Onychium japonicum, is known as the carrot fern, as its foliage resembles that of a carrot top. It hails from Japan, Thailand and India so isn’t fully hardy in the UK, although it should come through the winter in an unheated greenhouse. Height: 10-45cm

Fine fronds of the carrot top fern 9

Osmunda regalis

Also known as the royal fern, Osmunda regalis is a deciduous fern with a stately look, that can reach quite a size. Its foliage turns bronze in autumn. It likes a damp spot. Height: 1.5m

Advertisement Pale-green fronds of the royal fern 10

Polystichum polyblepharum

Polystichum polybelpharum is an easy-to-grow evergreen, also known as the Japanese tassel fern. The tips of the fronds are covered in golden hairs which give it an alternative name of the golden tassel fern. Height: 45-60cm

Golden tassel fern fronds

I have spent a lifetime acquiring plants from nurseries and gardens and then growing, or trying to grow them. I constantly reassure my two daughters that I’d be a wealthy woman if it weren’t for plants. They were dragged to enough nurseries and gardens in their childhood to nod knowingly in agreement.

It’s not surprising then that I know the names of lots of plants. One of my more recent passions is the hardy fern, particularly those with wintergreen foliage. They’re restful on the eye and their reassuring presence reminds me, when all else is in retreat, that the garden will return like a hibernating animal.

I buy them regularly; I plant them regularly. Once planted, I assumed the fern names would stick, as other plant names have done, but they’re as slippery as Teflon. They slide down the memory bank and disappear into a black void.

So I now have a collection of 50 or so ferns and I love them dearly, despite the fact that I can’t name them accurately even though I grow mostly five distinctive species – dryopteris, polypodium, polystichum, adiantum and asplenium. Not having the names come to mind quickly is extremely frustrating, rather like getting into a different model of car and finding that you can’t start the engine.

It’s even more maddening because male fern admirers seem to be able to trip the names off their tongues with ease. Perhaps the ability to remember botanical names is linked to testosterone, like spatial ability. Scientists have apparently proved that “spatial intelligence” is affected by the female hormone oestrogen. Presumably my fern naming would improve if I took a course of testosterone, along with getting the right lid on the right saucepan.

Although not a botanist, I do understand the recurring descriptive additions to fern names such as cristata (crested), crispum (frilly-edged), crenatum (scallop-shaped), frizelliae (very crinkled like the lettuce), fimbriatum (with a small fringe), congestum (busy, like the M25 on a Friday evening), grandiceps (large-headed) and sagittata (arrow-shaped). I’m not so sure of the difference between ‘Grandiceps’ and ‘Grandiceps Askew’, however, the latter is described by the fern king Martin Rickard as neat, but rare. It’s possibly only a couple of glasses of wine between upright and askew – which is where I may be going wrong, for I’m teetotal.

Some names reflect the collector, or raiser, such as Martindale (Lake District 1872), or Bevis (Devon 1876), or Druer (1900). These date from the Victorian era of fern fever, or pteridomania, when enthusiasts roamed the damper western half of Britain, where ferns tend to flourish, in search of the unusual and rare. Martindale, Bevis and Druer were all men, although bonnet-wearing ladies with baskets denuded the London area of ferns for their conservatories and terrariums. Luckily, ferns have a juvenile algal stage that allows them to return, decades later.

There are, of course, female fern fanatics, such as Angela Tandy of Fibrex Nurseries (fibrex.co.uk). She can name anything in the blink of an eye, although she is not suffering from a surfeit of testosterone, I hasten to add. She’s been working with ferns for 40 years on the family’s Warwickshire nursery. She says: “You get to recognise them. They’re like children and they’re all different.”

Her advice is to look carefully and say the name out loud every time you see your new treasure. Keep at it until you know it. Once you’ve learnt the name, look closely and learn to recognise the differences. Start with the foliage, then the colour of the stems, then look at how they grow, examining the detail – “rather as you would with snowdrops”, Angela adds.

I can do snowdrops Angela, just not ferns. Luckily, not knowing the name in no way diminishes the beauty of the fern, that’s what I tell myself.

Angela recognises that there are more male fern fanciers than women. They are “nerd-like” to use her words, but you have to be a nerd to undertake the 10-year process of raising ferns from spores in a dark place such as the wardrobe. I’d rather have shoes in mine. “Women just want to grow beautiful ferns that look lovely,” Angela adds. I’m with her there.

Top five favourite ferns for winter green

1. Asplenium scolopendrium Crispum Group

A small upright fern that must have moist shade and shelter from midday sun. The tongue-shaped leaves need careful placing because they scorch easily and turn yellowish in bright light. Angela loves the puckered edges of the leaves which look as though they’ve been gathered up round the edges, or “goffered” as Martin Rickard calls it. Like hair that’s crimped with tongs. Find it the right place and it will shine, away from the glare of the sun, offering a contrast to the lacier fronds. My best are in deep, moist shade.

Asplenium scolopendrium Crispum Group Credit: © Andrea Jones

2. Dryopteris affinis ‘Cristata’

The king fern is second on Angela’s list. This will thrive in dry shade once established, although it will grow in moist soil, too. All newly planted ferns must be watered in their first growing season, even if it says “dry shade” on the label. This upright fern gets big, up to 3ft (90cm), but the dark green crests on the top of the frond and on the sides (the pinnae) add weight so the ends of the fronds appear to curtsey.

It’s graceful as well as robust, but be aware that the fronds do deteriorate by midwinter. Cut them right back to the bare brown knuckles, as low as you possibly can, and the fronds will reappear with the bluebells, usefully covering foliage of early miniature bulbs such as snowdrops.

Dryopteris affinis ‘Cristata’ Credit: Alamy

3. Polypodium x mantoniae ‘Cornubiense’
A fern for dryish shade once established. “Once it’s happy it will produce three types of frond: plain, crested and heavily lacy.” This is a good ground-cover fern because polypodies are wider than they are taller. It will meander and saunter along without being an aggressive spreader. Like all polypodies, it is divided in August and September when it starts back into growth after a summer holiday.

Polypodium x mantoniae ‘Cornubiense’ Credit: Alamy

4. Athyrium filix-femina Plumosum Group

“This feathery airy-fairy fern needs moisture because the fronds will shrivel if it becomes too dry,” Angela warns. Given some shade, the light green lacy fronds are as dainty as paper doilies.

Athyrium filix-femina Credit: Alamy

5. Polystichum setiferum # ‘Pulcherrimum Bevis’

This is Angela’s favourite. “The architectural fronds appear in April, it’s evergreen and it’s no bother because you can grow it in a border in dappled shade, though not deep shade. It’s the perfect fern,” she says. I think of it as a feathery, elegant, shiny green shuttlecock with russet-brown bristles. Polystichum means “many-bristled” (which helps if you are name-challenged, like me).

Pulcherrimum Bevis Credit: Alamy

On good soil ‘Bevis’ will become large and luxuriant; you can divide a mature crown, should you wish to, between April and August. Mine, which was a division from a friend, took several years to shine – ferns are best planted small and left to develop, in my opinion. Now it is a fine specimen, so give this one some space to shine. Tidy it as the new fronds appear.

Most ferns are divided in the growing season between April and August. The exception is the summer-dormant polypody which needs to be tackled in August or September once it starts into growth once again.

Many of us think of “Jurassic Park” when we think of ferns (Pteridophytes) — abundant, spiky greenery thrashing about as huge dinosaurs crash through the forest in pursuit of human intruders.

At 300,000 million years old, they were, indeed, among the dominant plant species when dinosaurs roamed the Earth. And as many as 15,000 species now call our planet home.

Scientists aren’t exactly sure how many species exist, because new ones are still being discovered in unexplored tropical areas, according to Encyclopedia Britannica. But we know there are more than enough for you to choose from to include in both your landscape and inside your home, as these green beauties are versatile additions to either place.

While ferns are relatively easy to grow, you’ll want to understand some of their peculiarities before diving in. Let’s get started!

Plant Data

Ferns are vascular types of greenery, land plants with rigid, woody tissues that form “tubes” used to conduct water and minerals throughout. They reproduce via spores and have neither seeds nor flowers, and are distinguished from other spore-bearing plants, such as moss, by the fact that they have true roots, stems, and complex leaves.

A spore is a reproductive cell that can develop into a new individual without joining with another reproductive cell. And spore-based plants are evolutionarily much older than seed-based ones.

Instantly recognizable by their lace-like fronds (divided leaves) and hues of green ranging from olive to chartreuse, ferns are the Kevin Hart-Shaquille O’Neal of the plant world, varying in size from a quarter inch to as tall as 80 feet.

A Shady Character

Because ferns evolved in the shadows of the giant conifers that dominated the landscape in the time of the dinosaurs, they are generally fond of indirect light. This makes them a wonderful go-to for areas of your garden that are shady – and frustrating to fill since so many plants want sun, sun, and more sun.

Of course, there are exceptions to every rule. Some species — which may be evergreen or deciduous — will do well in sunny areas.

They are also very geographically diverse. “There are ferns that do well in almost every area of the United States,” says Skip Richter, a county extension agent with Texas A&M Agrilife Extension Service. “Check with a local source to find the best varieties for your area,” he recommends.

For example, ‘Lady in Red’ — characterized by lacy, light green fronds — does well in USDA plant hardiness zones 2-8. Happy a little further south in zones 3-9 is ‘Lady Fern,’ a longtime staple that’s very hardy. ‘Japanese Holly fern,’ successfully grown in zones 5-10, has “leaves” that are leathery and serrated, resembling holly.

If you want a true “Jurassic Park” experience, you might plant bracken (Pteridium) fern — it is one of the oldest and most evolutionarily persistent ferns. Scientists have identified bracken fossils that are more than 65 million years old. But beware — bracken can be be quite invasive with its extensive branched rhizome, which may grow to 1,300 feet in length.

All of these varieties (and more!) are available from Nature Hills Nursery.

Hungry, Thirsty All the Time

Whether grown in sun or shade, “they almost always want a high organic matter soil that’s moist,” says Richter. “A forest floor, for example, is ideal. The decaying leaves and understory lighting are just what they need,” he adds.

Adding these ancient treasures to a landscape that mimics those conditions will likely offer the best chance of success for most varieties, Richter says.

A top dressing of organic matter every now and then will ensure your plants are well fed. Keep in mind that they generally prefer soil that is more acidic than alkaline.

Again, there are exceptions, but most prefer a highly moist environment, such as in a humid forest or along a water source.

In the home garden, mimic these conditions by applying plenty of water if rain is infrequent. Keep the top 6 inches of soil moist but not soggy.

Transplanting and Propagating

Spring is the best time to transfer these plants from one place in the garden to another. If installing from a container, any time is fine. In either case, you may want do the work when it’s cloudy, to lessen the shock to the plant.

Simply dig a hole about the same depth as its container or root ball and twice as wide. Remove the plant from the container and place it in the hole; then fill in with organic soil. Water well, and add a layer of mulch to retain moisture.

You can also propagate these multifaceted plants by dividing them.

Start by watering the plant the day before you intend to divide it. Gently dig up the plant (or remove it from its container) and then cut or pull it into two or three clumps.

Each clump should have at least one growing tip — this is the structure from which the fronds grow. Replant the clumps as desired and keep the starts moist until you see new growth.

Creating new plants from spores is trickier, and takes a long time, but it can be done.

Choose spores when they look plump and furry. Remove a healthy frond and place it in an envelope or between two pieces of paper to dry out, then shake to loosen the spores.

Dust the spores over wet, organic, and sterile soil in a flat tray with a lid. Before you add the spores, you can microwave your soil to kill any pathogens. Heat for about 90 seconds on full power for every two pounds of soil. Don’t microwave seeds or spores as that will likely kill their ability to germinate.

Place the tray indoors in indirect light, and keep the soil moist at all times. Eventually you’ll see a green coating on the surface of the soil; many months later you will see small fronds popping up.

Some varieties produce stolons, or runners. To create a new plant from one of these, simply “pin” the runner to the top of the soil using landscape staples or a small stone.

Keep moist and look for new growth. At this point, you can cut the stolon from the mother plant and transplant as desired.

The Great Indoors

Because of their low light requirements, ferns make terrific indoor container plants. To provide indirect light, place near a north-facing window. Avoid south or west facing windows, because too much sunlight can scald the fronds.

Maidenhair grows nicely indoors.

As many indoor environments tend to be quite dry, be sure to water indoor consistently and provide an adequately humid environment. Try situating them in a bathroom, for example.

Other ways of increasing humidity, according to the University of Vermont Extension Department of Plant and Soil Science, include placing the pots on a water-filled, pebble-lined tray, placing a room humidifier nearby, or misting them occasionally. Thirty to 50 percent humidity is the sweet spot for these prehistoric plants.

While a fern is actively growing, the University of Vermont recommends fertilizing by applying liquid houseplant fertilizer at about one-half the recommended rate.

Asparagus fern is a beautiful evergreen, commonly grown as a houseplant, and related to the asparagus vegetable. There are several varieties, none of which are actually types of fern at all.

Maintain your indoor plants’ healthy appearance by occasionally trimming away brown fronds.

Popular varieties for growing indoors include Boston (Nephrolepis exaltata), Button (Pellaea rotundifolia), Kangaroo Paw (Microsorum diversifolium), and Silver Brake (Pteris cretica ‘Mayi’).

And while asparagus fern is a popular houseplant, it is not a true fern. It is a member of the lily family.

Need More of this Lacy Beauty?

If you decide these shade-lovers are really your thing, you might want to first visit Fern Canyon. This is an actual place in Humboldt County, California, where 80-foot canyon walls are clothed in thousands of lush plants, and where parts of “Jurassic Park 2: The Lost World” were filmed. And then, consider joining the American Fern Society, where you can exchange information and spores with other fern fans.

Do you fiddle with ferns? Tell us about your passion for this plant in the comments section below.

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About Gretchen Heber

A former garden editor for a daily newspaper in Austin, Texas, Gretchen Heber goes through entirely too many pruners and garden gloves in a year’s time. She’s never met a succulent she didn’t like and gets really irritated every 3-4 years when Austin actually has a freeze cold enough to kill them. To Gretchen, nothing is more rewarding than a quick dash to the garden to pluck herbs to season the evening meal. And it’s definitely time for a happy dance when she’s able to beat the squirrels to the peaches, figs, or loquats.

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