When to prune ferns?

Should this year’s asparagus fern be cut in the fall?

Varietal dormancy differences. Photo Credit: Dan Brainard, MSU.

Many asparagus fields in Michigan have begun the dormancy process, turning from the chlorophyll-green color that typifies photosynthesizing plants to a bright, vivid yellow. The loss of green pigment signifies that these plants are no longer photosynthesizing, but does not indicate full dormancy. That state has only been reached when the fern turns the same light brown color that one sees on dormant pasture or mature cornfields. Asparagus fern can be mowed or chopped any time after the “dormant brown” color is seen without losing any of the energy that will go into making next year’s spear crop.

Some varieties of asparagus seem to reach this state earlier than others. Canadian hybrids like Millennium or Tiessen are bred to have a quick and complete dormancy response, going from green to yellow to brown in a matter of a few weeks, often allowing growers time to chop fern before winter snows set in. New Jersey hybrids, such as Jersey Supreme and Jersey Giant, have a much slower dormancy response and are often still mostly yellow or even green when heavy snow makes field activities impossible.

Even if fern reaches full dormancy before winter weather makes chopping or mowing impossible, there are two schools of thought on whether the fall is the correct time to do this necessary chore. Many growers prefer to leave dead fern standing as a way to trap additional snow that might otherwise blow off the field. Standing fern may well catch and hold snow equivalent to an additional inch of rain. That water should be available to the dormant asparagus crown when growth starts in the spring. However, other asparagus farmers, especially the larger growers or growers of other spring planted crops, are often pressed for time when weather clears in the spring. Getting the chore of mowing dead fern out of the way in the fall frees up time for other spring tasks like spreading fertilizer or applying pre-emergence herbicides. These growers count on normal spring rains to provide adequate moisture for growth.

Ultimately, the choice to chop or mow old asparagus fern in the fall or spring comes down to the preference of the grower.

The Ins and Outs of Beautiful Boston Ferns

I always knew Boston ferns (Nephrolepis exalta) were special. I’ve had a soft spot for these tropical beauties since spending a mild winter in Georgia. My landlady had the greenest, most enormous ferns I’d ever seen on the porch of her rambling southern home. When I got married that spring, she brought them to help decorate the chapel. They filled her car, adding another over-the-top element to an outstandingly beautiful day.

My grandmother had a much-complimented Boston fern at the farmhouse where my mom grew up. Every fall, it was brought inside, and my mother had the unenviable job of picking off all its browned fronds. In spring, it was cut back hard, and its pot was replenished with the richest compost that could be scratched up, one handful at a time, from beneath big trees in the woods. Two weeks later, it would be huge and lush, ready to hang on the front porch for all to enjoy.

Grandma loved roses best of all, but my mom will choose a pretty fern over a rose any day. I picked up an enormous Boston fern for her last spring. Yellowing outer leaves had it marked down to $10, but I knew it just needed a helping hand. The fern was so tightly rootbound that it could no longer absorb moisture. Water just ran right through the pot.

Remembering how Grandma’s potted fern had been refreshed every year, I knocked off as much old soil as I could to make room for fresh potting mix. I loosened the roots and pruned back a few of the longest ones. When we brought it up a week later for Mother’s Day, it was bursting with healthy new growth.

Ferns love water, so I put an extra tablespoon of polymer moisture crystals into the bottom of the hanging basket. The hanging container I chose has a self-watering bottom. Dad had no trouble keeping Mom’s fern well watered by refilling the saucer reservoir every couple of days. When “his” Carolina Wrens started looking at the fern as a nesting site, he was even happier to be able to water it from below!

They’ve had ferns on the back porch before. Usually they look pretty tired and beat-up by the end of summer, and Dad sneaks them into the compost pile. This one just got larger and prettier all summer, though, so Mom made sure it came in before the first freeze. They asked me to over-winter it for them. I looked around my crowded window areas and wondered where I’d find a place for such a big plant. Then my friend Sharon gave me great advice: Don’t wait until spring to cut it back!

I gave that fern the haircut of its life, taking all those green fronds down to two inch stubs. Seeing some small new fronds emerging between all those chopped ends gave me hope that I hadn’t killed it with such extreme pruning. I put it in a north window for partial sun and gave it enough water to keep it going. By Mother’s Day, I hoped it could resume its pride of place on my parents’ back porch. (Unfortunately, I forgot to water it once too often, but I’ll try again with this year’s fern!)

Pruning a Boston Fern way back in fall means far less space is needed for over-wintering. It will gradually put out new growth, but it won’t grow out as quickly during winter as it would after a spring trim. By spring, the foliage will be large and full again.

As with any plant kept indoors, introduce it gradually to outside conditions. Those tender indoor stems need to toughen up and be hardened off before the plant can be out all day. If a spring frost threatens, be sure to bring it back inside for the night.

Boston ferns are easy growers if you’re willing to do the “in and out dance” with them as the seasons change. With annual pruning, the plant will renew itself for many years, providing a striking focal point in both winter and summer. Reserve a place for this cool, green beauty, and listen to the compliments roll in!

Photos by Jill M Nicolaus. “Mouse over” images and links for more information.

Pruning Boston Fern – How And When To Prune Boston Fern

Boston ferns are among some of the most popular houseplants grown and common attractions found hanging from many front porches. While these plants come in various sizes and shapes, most can get quite full. Oftentimes, it is necessary to cut back Boston ferns in order to maintain their vigorous form.

Trimming Boston Ferns

When it comes to pruning Boston fern plants, you should always look towards its leaves for inspiration. It is not uncommon for this plant to exhibit old, discolored fronds. These fronds may be yellow or brown.

Older leaves often get shaded out by new growth. The plant may also have leafless runners dangling down from the plant. These are all good indications that trimming may be needed.

Unsightly plants with erratic growth can always benefit from pruning to maintain an attractive shape as well.

How & When to Prune Boston Fern

While routine trimming of discolored and unattractive foliage can be performed at any time, severe pruning is best accomplished in spring or summer. An ideal time for pruning is during repotting,

when plants can be dramatically cut back. In fact, Boston fern responds well to severe pruning, which encourages more prolific, bushy growth and corrects dull, leggy growth.

When pruning Boston fern, always use clean, sharp pruning shears or scissors. Since pruning can be messy, you may want to move the plants outdoors or place an old sheet in the area to catch the cuttings.

You don’t want to crop the top of the plant when pruning Boston fern. Instead, trim off the side fronds at the base. Also remove old, discolored fronds near the soil to allow new growth to come through. Remove the unsightly stems to the base as well. The remainder of the plant can be clipped along the outer edges to the desired shape. Likewise, you may choose to cut the entire plant back to the base if necessary.

Boston Fern Yellow Leaves

Yellow leaves can signal a number of things. For instance, stressed out plants can develop yellow leaves, especially when they are adapting to a new environment. Improper watering can also lead to yellowing leaves.

Boston ferns should be kept consistently moist but not soggy. Dry air can be a factor as well. Misting plants and providing additional humidity can often alleviate this problem.

Pot bound plants will sometimes turn yellow. In addition, it is not uncommon for fronds to turn yellow and then brown as they age. Simply remove any yellow leaves that may be present.

Boston Fern Prune Brown Leaves

Brown leaves are another common occurrence in Boston fern plants. As with yellowing, there may be multiple reasons. Brown edges or tips could be due to uneven watering or too much fertilizer. Generally, Boston ferns should only be fed twice a year (spring/summer).

Compacted soil or overcrowding can also lead to brown leaves.

Finally, too much contact with the plant can affect the foliage. Touching plants with your fingers can actually cause brown spots to form on the leaves of Boston fern.

Prune brown Boston fern leaves at the base as they appear.

  1. First, get the tools you need ready. I prefer to use my Fiskar Sheers that have about an 18” “scissor” blade which make quick work of the job and are fun, safe and easy to use. Plan to spend around $25 for a good pair of shears like this. I also use my pair of (also Fiskars) Smooth Action Pruners which is a small hand-held pruner for more detailed and careful trimming around any new growth that’s already started.
  2. Before you cut, inspect. Take a look at the base of the plant by moving the fern’s fronds around. Look for small “fiddleheads” poking up. These are new fronds (leaves) so you will not want to cut those off.
  3. You might be thinking, “my fern is still green and looks nice, why would I want to chop all that off?!” – and that’s a good question. But trust me, you will be happy later in the year when you get lush growth popping up with a nice clean look.
  4. As you begin cutting, you can cut nearly all the way down to the base of the fern without harming it. So go deep and leave just a few inches sticking up. Older ferns will have a pretty substantial base, especially those that were not regularly trimmed while newer ferns won’t have as much base. Use common sense when cutting them back.
  5. The next step is the easiest but also possibly the hardest! Waiting for the new fiddlehead growth to start popping up, which depending on your type of fern and the local weather, could happen between a month and three months. Ferns begin their new growth in Spring however, so what I normally see is new growth really staring about 3 to 5 weeks after my Presidents Day trim!
It’s as simple as that! And as Ciscoe Morris says… “Oooh la la!”

The beauty of a tree-fern frond opening.

UP to 80 per cent of tree ferns die due to lack of information about siting and watering requirements.

Tree ferns, or Dicksonia antarctica, are sold in increasing numbers. Sometimes they are taken illegally, but more typically, tree ferns are removed from the bush by qualified horticulturists and sold only under strict licensing regulations by the various state park and wildlife services and the Commonwealth government.

Cedric Bryant.

All retail tree ferns are tagged with a serial number issued by the particular government authority and markets are regularly checked for ferns being sold illegally.

Some of the healthiest tree ferns are from Tasmania, almost their natural home where, when sold, have a solid fern stem more than 30cm.

I saw one large unit development, not far from where I live, where ferns had been planted exposed to full sun plus the reflected heat from the white building. They lasted a couple of months and only because it was cooler!

If you have no natural shade plant on the south side of the home, use a 90 per cent shadecloth.

Have a look at tree ferns growing in the Rainforest Gully at the National Botanic Gardens or on Clyde Mountain. Here are the main pointers to prevent further tragedies:

  • Buying: Always select healthy ferns free from physical or insect damage. Always buy from a registered garden centre and make sure the fern has the authorised tag.
  • Siting: Tree ferns require shade, ample moisture and good drainage. They must be protected from severe frost. In their natural environment they are shaded by overhead evergreen trees.
  • Planting: In heavy soils dig in plenty of rotted organic matter such as cow manure (not chook), decomposed leaves with some washed river sand. In their natural state they continually benefit from falling leaves. The use of Multicrop liquid Ground Breaker will be beneficial in clay soils rather than gypsum. When planting, place one third of the trunk in the ground and fill in with soil with the added organic matter. Make a small bank around the trunk to hold a minimum of a bucket of water to which has been added liquid seaweed plant food. This will encourage hormonal activity and new root growth.
  • Watering: Tree ferns should be watered in the crown as well as the base. With drip irrigation, it’s ideal to connect a 13mm line to the top of the fronds making a circle. Deep water around the base once a week, keeping in mind tree ferns come from high rainfall areas.
  • Feeding: Only use certified organic fertilisers and, ideally, apply on a three-month cycle. I recommend the liquid variety rather than the pellets to penetrate the roots faster.
  • Pests: The only real pests are scale insects, usually indicated by ants. These in themselves don’t damage the fronds; they merely feed on the sugars sucked out of the scale insects. If in doubt, take a sample in a plastic bag to your nearest garden centre for identification. Multicrop certified organic EcoPest will fix scale, mites and other sucking insects.
    The Rainforest Gully at the Botanic Gardens.

Jottings…

  • If the leaves on deciduous trees are suddenly turning yellow, it’s not autumn arriving early. At this stage they are almost certainly suffering from lack of water. A good, really deep water is essential. Silver birch, Golden Elm and Ash are particularly vulnerable.
  • It’s vital not to let lemon trees dry out and, as the fruit is developing, feed very regularly. Yates Liquid Dynamic Lifter, Neutrog Seamungus or Maxicrop seaweed plant food are all ideal.
  • Resist pruning shrubs until the hot weather has gone, but deadhead perennial plants after flowering.

Gardening Answers Knowledgebase

Search Results for: Ferns | Search the catalog for: Ferns

  • Plant Answer Line Questions: 3
  • Garden Tips: 2
  • Book Reviews: 1
  • Recommended Websites: 3

Recommended Websites

American Fern Journal

Hardy Fern Foundation

Ferns Resource List

More websites

Plant Answer Line Question

Keywords: Matteuccia, Ferns

I have ostrich ferns and I was wondering if there is anything special that I should do for them for the winter. What I have been doing is putting ground up leaves in the bed, but beyond that, I’m not sure if there is anything else I should do.

Answer:

Andrew MacHugh’s book, The Cultivation of Ferns (1992) says the following (from p. 47):

“In autumn, a mulch of well-rotted leafmould, peat or bark chippings should be given to ferns planted in open sites. In winter the fronds of deciduous ferns can be cut back to an inch above the crown. In areas subject to frost, the decayed fronds will provide some protection to the plant and should not be removed until the spring growth of new fronds shows signs of emerging.”

Date 2019-07-17

Keywords: Pteridium aquilinum, Perennials–Care and maintenance, Ferns

My question has to do with the fall/winter foliage of bracken fern (Pteridium aquilinum). A friend trimmed the bracken to the ground. Will the bracken grow back next spring? This led to other questions. Does bracken lose only its leaves in the winter or does the entire plant die off? Does it spread through its roots or spores? Any information you have would be appreciated.

Bracken is deciduous, that is, the fronds die to the ground in winter and then regrow from the rhizomes in the spring. If your friend cut her bracken down to the ground late in the year there would be no problem. Even if it was earlier in the year, the bracken would probably survive. According to the fern books I read, people have tried mowing to remove their bracken with no success. The books also warn that bracken is very invasive and not recommended for small gardens. It spreads by underground rhizomes, maybe by spores as well, and can take over a large space in a very short time.

It might be a good idea to take a look at some pictures either in books or online (just enter the name in Google and select Images above the search box) to make sure this is what your friend has. Any deciduous fern (and even some evergreen ferns) can be cut to the ground in fall, but generally it is better to wait until the new fronds appear in spring to cut out the old fronds of evergreen ferns.

The USDA Plants Database provides further information.

Sources consulted:
The Plantfinder’s Guide to Garden Ferns (by Martin Rickard, 2000)
Ferns to Know and Grow (by F. Gordon Foster, 1984)

Date 2019-07-17

Keywords: Dryopteris, Pruning, Ferns

My wood ferns (now about 4 feet in diameter)have fronds which are now partially brown. Can I prune all the ‘old’ fronds off and let the new ones take over without damaging the plant? When should I do this?

Sources are divided on when and whether to prune wood ferns (Dryopteris). Some consider Dryopteris “self-cleaning,” meaning that the old fronds will eventually disintegrate on their own (Gardening with Woodland Plants by Karan Junker; Timber Press, 2007). If you are inclined to tidy up the look of your plants, they can be pruned of their old fronds after new growth begins in the spring (be careful not to cut the new fronds), or according to other sources, in late February or early March before new growth starts. Rainyside Gardeners and Great Plant Picks, two Pacific Northwest resources, offer more information. Rainyside advocates pruning once there is new growth, and Great Plant Picks advocates pruning before new growth begins.

Date 2019-08-02

Garden Tip

Keywords: Seed dormancy, Propagation, Shrubs, Seeds, Perennials, Ornamental grasses, Herbs, Ferns, Reviews

A book by Jekka McVicar called Seeds: the ultimate guide to growing successfully from seed (Lyons Press, 2003, $22.95) will help you turn your seedy hopes into plant reality. Thirteen chapters are divided by types of plant including ferns, grasses, shrubs, perennials and herbs. The practical information that applies to all kinds of seeds, such as what type of soil to use, and how to break seed dormancy, is included in the last chapter. Color photos illustrate throughout. For online tips for seed starting go to:
http://cru.cahe.wsu.edu/CEPublications/pnw0170/pnw0170.pdffrom Oregon State University.

Date: 2006-03-01

Keywords: Polystichum, Cyrtomium, Blechnum spicant, Plant and garden societies, Polystichum munitum, Ferns

To create a desert oasis look plant a few hardy palms and then add evergreen hardy ferns such as Deer fern (Blechnum spicant),Big leaf holly fern (Cyrtomium macrophyllum), Western Sword fern (Polystichum munitum), and Soft shield fern (Polystichum setiferum). Growing a few ferns usually leads to growing many ferns – there are so many cool species out there. Learn more about the world of pteridology (study of ferns) by joining the locally based Hardy Fern Society. Members receive a packet of fern growing information and a quarterly newsletter; they also participate in a spore exchange and produce the wonderful Fern Festival and plant sale each June. To join the society send $25.00 to The Hardy Fern Foundation, P. O. Box 3797 Federal Way, WA 98063-3797.

Date: 2007-04-03

Fronds and Anemones: Essays on Gardening on Nature by William Allan Plummer, 2017

Reviewed by: Brian Thompson on 2017-10-05

With fronds like these, who needs anemones? This old horticultural quip inspired the title Fronds and Anemones, a book of essays by William Allan Plummer. In his preface he warns, “I am an incorrigible punster, for which I make no apology.”

Fun aside, these collected essays reveal the author as a keen and skilled observer of the native birds and wildflowers around his home in upstate New York. He also reflects on his discoveries as an avid gardener, with a particular interest in ferns.

This latter interest led him to join the Hardy Fern Foundation. In the summer of 2003, this organization, along with the British Pteridological Society, sponsored a “Best of the West Fern Excursion” to explore both the gardening and natural attractions found in Washington State. The emphasis, of course, was on those sites rich in ferns.

The resulting essays, which form a significant part of this book, make an outstanding travelogue to some of the best gardens of the region. These include public gardens such as the Elisabeth C. Miller Botanical Garden and the Rhododendron Species Botanical Garden, but many private gardens are featured, too.

These travel stories were originally published in the Hardy Fern Foundation Quarterly, Volume 14, No. 1 and 2 (Winter and Spring 2004). Those issues are available in the Miller Library, but I recommend reading Plummer’s writings in the context of his other fine work found in this book.

Published in the October 2017 Leaflet Volume 4, Issue 10

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