Making a bog garden

Grow a Bog Garden in a Pot

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You dont need much space to enjoy a few wonders of nature. In fact, I have everything I need here to create a bog-like garden for my balcony.

Carnivorous plants like the pitcher plant (Sarracenia) and sundew (Drosera) grow in wet acidic environments known as bogs. This curly reed (Juncus), elephant ears (Colocasia), chameleon plant (Houttuynia cordata ‘Chameleon’) and moneywort (Lysimachia nummularia) grow in wet soggy areas in or next to ponds.

Once you select the plants, find an all-weather pot without drainage holes. Mix equal parts of clean sharp sand and peat to create your planting mix.

Arrange your plants to provide a pleasing display, making sure the tall plants do not overshadow the smaller ones. Set the plants in the potting mix so the crowns are just above the soil surface.

Grow in a sunny location and water as needed. Tap water is usually ok, but rainwater or water collected in your rain barrel, or dehumidifier will be even better.

A bit more information: Grow tropical and carnivorous plants like the Venus flytrap (Dionaea muscipula) indoors in a terrarium. The plants will thrive in the moist humid environment. And the whole family will have fun feeding flies and other insects to the carnivorous plants.

How to make a bog garden

A bog garden can be created by adapting an existing soggy area, or from scratch, either at the edge of a pond, or as a standalone feature. Permanently damp, it creates an area where moisture-loving plants thrive. These plants are different to those suited to the standing water of a pond, so will attract a host of different wildlife.

A bog garden may be a better option than a pond for families with young children. Like a pond, it should attract frogs, toads and even grass snakes. Dragonflies and damselflies will perch on the taller grasses, and bees and butterflies will flit around the flowers.

Planning your bog garden

  • Decide on size. Lay out a length of rope or hose to help you to work out the size of your bog garden. Beware of making it very large, though, as it will be harder to maintain and stepping stones may be required.
  • Research your plants. Unlike pond plants, bog plants thrive in soil with high nutrient levels and that contain lots of organic matter. There is a huge range of exciting bog plants, from striking gunneras to tiny water forget-me-nots. A little research will reveal their partialities, for instance, whether they are sun- or shade-loving, the degree of damp and acidity preferred, and the amount of space they require.

Establishing your bog garden

  • Pick a spot. Making an artificial bog is very like making a pond. Pick a spot on level ground, away from overhanging trees.
  • Dig a hole. Dig a hole about 30 cm (12 in) deep.
  • Lay a butyl liner in the hole. Make a few drainage slits in the liner and return the excavated soil, mixed with some organic material, to the hole.
  • Water the soil thoroughly. Try to use rainwater, especially if the soil is acidic. If tap water is the only means of filling, let it stand for a few days to allow any additives to break down.
  • Leave the soil to settle for about a week before planting up.

Maintaining your bog garden

  • Plant a combination of short and tall plants for cover and perches.
  • Be careful what you plant as some species can be vigorous, aggressive or very large, such as pendulous sedge and gunnera.
  • Think about planting so that there is a range of flowers throughout the year, from marsh-marigold in spring, to hemp-agrimony in autumn.
  • Water your bog in drought, but respect hosepipe bans. Try to use rainwater if you can.
  • Include stepping stones if you bog garden is very big. This will help you to get to the plants as you maintain them without compacting the soil.

Top tips

  • If you’re digging your bog garden into turf, place the sods grass-side down around its edge for an instant, nutrient-rich planting medium.
  • If a bog garden’s not possible, a miniature version can be created in a container, and planted up. This will probably dry out quicker than a traditional bog garden, so will need topping up with water frequently.
  • ‘Palustris’ and ‘ulignosus’ mean ‘bog’ or ‘marsh’ in Latin, so look out for these words in the names of plants, for example, Caltha palustris. It shows that they are appropriate for this environment.

Suggested species:

  • Creeping Jenny – Lysimachia nummularia
  • Hemp-agrimony – Eupatorium cannabinum
  • Marsh-marigold – Caltha palustris
  • Meadowsweet – Filipendula ulmaria
  • Plantain lily – Hosta spp.
  • Purple-loosestrife – Lythrum salicaria
  • Snake’s-head-fritillary – Fritillaria meleagris
  • Water Avens – Geum rivale
  • Yellow Iris (aka Flag Iris) – Iris pseudacorus

Plants For Bog Gardens: How To Build A Bog Garden

Nothing beats the natural appeal of a bog garden. Creating an artificial bog garden is both fun and easy. Most climates are suitable for growing bog garden plants. They can be designed in various ways based on your landscape and personal needs. Keep reading to learn more about how to build a bog garden.

What is a Bog Garden?

Creating a bog garden in your landscape is an enjoyable project that allows you to experiment with different plant species. So exactly what is a bog garden anyway? Bog gardens exist in nature in low-lying areas, or around ponds, lakes or streams. Bog garden plants love overly moist soil, which is waterlogged, but not standing. These marshy gardens make a lovely attraction in any landscape and can quickly turn an unused, water-logged spot in the yard into a wonderful scenic attraction.

How to Build a Bog Garden

Constructing a bog garden is not a difficult task. Choose a site that receives at least five hours of full sunlight. Dig a hole that is about 2 feet deep and as wide as you would like your garden.

Line the hole with a sheet of pond liner and press it down so that it contours with the hole. Leave at least 12 inches of liner exposed to accommodate for the bog settling. This edge is easy to hide later on with mulch or small rocks.

In order to keep the plants from rotting, it is necessary to poke drainage holes around the edge of the liner, one foot below the soil surface. Fill the hole with a mixture of 30% coarse sand and 70% peat moss, compost and native soil. Allow the bog to settle for one week and keep it well watered.

Choosing Bog Garden Plants

There are many perfect plants for bog gardens that will naturally adapt to the moist environment. Be sure that you select plants that are appropriate for your growing region. Good choices for a bog garden include some of the following beauties:

  • Giant rhubarb – has massive, umbrella-shaped leaves
  • Giant marsh marigold – grows up to 3 feet tall with beautiful yellow flowers
  • Flag iris – can be purple, blue, yellow or white with tall stalks and dark green leaves

Other plants for bog gardens include carnivorous species such as Venus flytrap and pitcher plant. Many woodland plants feel right at home in the boggy environment as well. Some of these include:

  • Jack-in-the-pulpit
  • Turtlehead
  • Joe-pye weed
  • Blue-eyed grass

Be sure to put taller bog plants in the back of your bed and provide plenty of water.

Container Bog Garden

If your space is limited or you are not interested in excavation, consider a container bog garden. A bog garden can be created using any number of containers including whiskey barrels, kiddie swimming pools and more. Virtually, any relatively shallow container that is wide enough to accommodate some plants will do.

Fill 1/3 of your chosen container with gravel and put a mixture 30% sand and 70% peat moss on top. Wet the planting medium completely. Let your container bog garden sit for one week, keeping the soil wet.

Then, place your bog plants where you want them and continue to keep the soil wet. Put your bog garden container where it will get at least five hours of daily sun.

Gardening How-to Articles

A Bog Garden

By C. Colston Burrell | June 1, 1997

Few gardeners are lucky enough to possess a moist spot, much less a true bog. I garden in Minneapolis on a dry terrace adjacent to the Mississippi River, in silty loam above limestone bedrock. For an ardent plant collector such as myself, lack of moist soil is a cruel fate. I love turtleheads, sedges, skunk cabbage and iris, plants of low woods and wet meadows which demand continuous moisture to thrive. In my dry, silty soil, it seemed impossible to even think of growing them. Impossible, that is, until I thought of creating an artificial bog garden.

Natural bogs form in glacial lake beds and shallow depressions over hundreds of years. My challenge was to create a consistently moist soil environment for plants on a flat, well-drainedriver terrace. Employing the same technology available to water gardeners who build artificial ponds, I used a plastic-lined trench. But instead of filling the liner with water, I filled it with soil. Unlike a true marsh, which has open water, my bog provides a haven for plants that like wet feet; there is no standing water.

Keeping the soil moist was not the only consideration in the making of my bog. The relationship of the new bog garden to the overall landscape design was also paramount—I didn’t want the bog garden to look like a botanical freak show. My garden is laid out formally. A rectangular lawn and terrace form a long axis, flanked on both sides by eight-foot-deep beds. The bog garden had to complement and maintain the integrity of this design framework, forming an exuberant planting bed with lots of relaxed and tumbling plants to mirror the one on the opposite side of the lawn. I decided to run the bog garden for 25 feet along the entire length of the lawn. On either end, it blends imperceptibly into the existing beds, creating a visually unified whole. Though the lines of the garden are rectilinear and formal, the overall effect is relaxed and comfortable. The velvety lawn is surrounded on all sides by lush plantings. The bog garden fits in perfectly.

Building a Bog Garden

Because small excavations dry out quickly, a bog garden should be as large as possible. Ideally, it should be at least 2-1/2 feet deep.

Once the size and shape of the new bog were designed, the most challenging task was excavating the hole. I decided to make the bog two feet deep. In retrospect, I should have dug down to three, allowing the dictates of the plants to determine the bog’s depth rather than my physical stamina. Since small excavations dry out quickly, the larger you make your bog garden, the better. Deeper soil is more accommodating to the root systems of mature plants. In other words, if you are thinking about designing several small bog gardens, you would be better off with one large one at least 2-1/2 feet deep.

Starting at one end, I dug the trench to its full depth as I moved down its length. While digging, I kept the walls sloped outward slightly from the bottom of the trench to keep them from caving in. To protect the lawn, I piled the soil on a tarp. The mountain of soil that grew next to the pit caused quite a stir on the block. Neighbors appeared from all corners to investigate. The 8-foot prairie plants I had used in the front garden had made them suspicious. But when they heard I was building a bog, they thought I had really lost it. Now that the hole is filled and the plants are in place, they can’t even tell that the bog is there.

After excavating, I lined the trench by rolling out an 8 mm plastic sheet. The use of a single, unbroken sheet is important because the seams created by using several overlapping sheets will not hold water.

Some drainage is necessary to keep the crowns of the plants (the point where the roots meet the top growth) from rotting. Because I garden in USDA zone 4, where winter temperatures reach -30 degrees F, I was also concerned about the cold. I didn’t want water and ice to come into contact with the crowns, so I placed drainage holes around the periphery of the liner, a foot below the soil surface. By duplicating the conditions under which many plants grow in the wild, I ensured that the top of the soil—where the crowns are—remains relatively dry, while the roots are kept moist.

Poke drainage holes around the liner, about a foot from the top, to keep plant crowns from rotting.

After unrolling the plastic sheet and centering it over the trench, I let it settle in, checking to make sure that the liner fit the excavation’s contours. Then, I filled the trench with a mixture of half compost and half excavated soil, packing it down as I went, until it mounded in the center. It is important to fill the entire trench level by level to insure that the liner falls into place evenly along the entire length, and to tamp down the soil as you go.

Some people install perforated pipes in the corners of the bog to expedite watering. The pipe is buried vertically, with the bottom of the pipe extending down to just above the bottom of the liner. The top of the pipe sits 1 to 2 inches above the soil line. There are two ways to do this: The simplest is to use narrow, perforated tubing and run a hose inside of it to water the bog. However, water can run into the bog too quickly, backing up in the tube. The second method requires two perforated pipes. Place a narrow tube within a larger tube at least 10 inches in diameter. Fill the gap between the two with pea gravel. When watering, run your garden hose down the inner tube. This methods enables the water to seep into the soil more gradually. It is particularly useful for controlling the water flow in specialized acidic bog gardens (see “A Bog for Specialized Plants”).

I chose not to use pipes at all. My house has no gutters and so the bog, which runs the length of one side of the structure, collects all the water that runs off the roof each time it rains.

After adding the soil, I filled the new bog garden with tapwater and let it sit until the soil settled. I recommend waiting at least a month before planting, keeping the soil wet at all times. If you cannot wait a month—and few of us have such patience—wait at least a week. Smooth out the lumps in the the soil surface, keeping the mound in the center before you plant. Fill in with additional soil if necessary to keep a consistent level. Cut the plastic liner flush with the soil and you will never notice the seam between bog and lawn.

Bog Plants

The bog garden is a haven for plants like ligularia that like wet feet; there is no standing water. Growing pitcher plants and other species native to sterile acid bogs requires a slightly different approach.

Many of the plants that grow in the wet, peaty soils of bogs and other wetlands are beautiful garden plants for either sun or shade. Locate your bog according to which plants you wish to grow and how they fit in with the rest of your garden.

In nature, a bog contains plants that are uniquely adapted to wet, acidic soils—acidic because little or no water flows through the bog and so no acids are leached away. In an artificial bog, you can either grow these specialized plants or a wide variety of perennials, bulbs and shrubs which require constantly moist soils, such as bog rosemary, turtlehead and blue flag iris. I chose the latter approach for my garden. Building a specialized bog garden is discussed on the next page. Before buying plants, decide on which kinds you wish to grow, either garden plants or those suited to acid conditions.

The beauty of bog plants is not just in their flowers, but also in their foliage. I love their bold showy leaves—the arrowhead shapes, the umbrellas and the swords—which is why I love bog gardens. These shapes are even more striking when contrasted with delicate sedges and ferns, which also thrive in moist soil.

Maintenance

The most important maintenance job for an artificial bog garden is watering. Never let the soil dry out. Dry soil means sure death for moisture-loving plants. Mulch the garden with pine straw or oak leaves in the winter to help protect delicate plants. Leave the mulch in place, allowing it to rot into the soil. Top dressing with rich compost will also enrich the soil, keeping its level constant as the soil settles. As with any garden, remove weed seedlings before they become a problem. Weeds will be few as many of them do not thrive in wet soil. Depending on the location of your garden, tree seedlings may be a nuisance.

Other Ways to Build a Bog

Bog gardens can be difficult to work into the landscape. If you have a pool or pond, place the bog garden next to it, so that the bog blends harmoniously into the landscape. If you connect the bog and the pool with a length of pipe to allow the water to flow freely, the pond can provide water for the bog. This will also keep water levels in both enclosures constant.

If you don’t have room for an in-ground bog, you can still have a bog garden. Try using an old whiskey barrel or other container that holds water. I have seen kids’ wading pools, utility sinks and even old bathtubs used to make bog gardens. Your imagination is the limit. With a little ingenuity, anyone can have an artificial bog garden. So what are you waiting for?

Bog for Specialized Plants

Growing plants native to sterile acid bogs requires a different approach from the one I took in my garden. The environment of a true bog is unlike a low, wet woodland or meadow. A bog forms slowly in a glacial lake bed with the help of specialized mosses called sphagnum that grow inward from the edges of the lake. As they grow, the lower portions of their stems die but remain attached as the upper stems branch and spread, creating an interwoven mat.

At first the moss floats on the surface of the water. But as the mat grows and decays, it deposits peat on the lake bottom. As the sphagnum spreads outward, the floating mat becomes thick enough for other plants to take root and grow. Eventually, the sphagnum covers the entire lake, and the floating mat of vegetation is dense enough to support flowers, shrubs and even trees.

This kind of bog is called a quaking bog. Walking on it is like walking on a squishy waterbed. The ground trembles or quakes. To re-create this environment in your yard, you need to provide a sterile substrate on which the plants can grow. Clean, medium-coarse sand and peat moss are the best choices. Dig a trench as described in the accompanying chapter. Since most specialized bog plants have sparse root systems, two feet is generally deep enough. I recommend installing perforated pipe in at least two corners of the bog as you may be adding distilled water or rainwater collected elsewhere. A pipe 2 to 4 inches in diameter is ideal. For larger bogs, use the double-pipe system described above.

Fill the excavation with a 50/50 mixture of sphagnum and sand. A living layer of sphagnum at the top of the bog is desirable but may be hard to come by. Carolina Biological Supply Company is a good source. You can reach them at 2700 York Road, Burlington, N.C. 27215; (800) 334-5551.

It is imperative that you let the bog settle for at least a month before planting. The pH of the sand and sphagnum mix and the water need to come into balance before the plants are added. The additional time also allows the soil to settle. If it settles too much after the plants are established, it may bend or break their new roots.

Before planting, wash all the soil from the roots of the new plants to avoid introducing soil-borne microorganisms and worms. If you use live moss, add it after the other plants are in place. The moss is often slow to establish.

Use only rainwater or distilled water in the bog. Tapwater contains minerals and chlorine harmful to bog plants. It is also neutral to alkaline in pH, and bog plants need a highly acidic soil. As with all bogs, consistent water is essential. Bogs are naturally low in nutrients, so do not add fertilizer.

Because it requires so much diligent attention, a specialized bog is not for everyone. Do not waste time and doom plants to a slow death if you are unwilling to manage a true bog garden properly.

Many bog plants, such as pitcher plants, are becoming rare in the wild. If you choose to plant them, purchase them only from reputable dealers who propagate their own plants. Make sure you do not buy wild-collected specimens. Remember that “nursery-grown” does not mean nursery propagated.

A living mulch of sphagnum moss is desirable for an acid bog. Add an additional mulch of pine straw in winter to protect delicate plants, especially in areas where winters are cold and snowfall is erratic. Remove the mulch in the spring to allow the sphagnum to grow.

C. Colston Burrell is an avid plantsman, garden designer, and award-winning author. His books include Hellebores: A Comprehensive Guide (Timber Press, 2007), winner of the AHS Book Award; Perennial Combinations (Rodale, 1999), a Garden Book Club Best Seller; and A Gardener’s Encyclopedia of Wildflowers (Rodale, 1997). He is the editor of several BBG handbooks, most recently Native Alternative to Invasive Plants (2006) and Intimate Gardens (2005). He gardens on ten acres in the Blue Ridge Mountains of Virginia. Learn more at www.ccolstonburrell.com.

Creating a Bog Garden

Do you have a spot in your yard that seems unsuitable for planting because it’s always a bit on the waterlogged side? At first glance, it may seem like that bit of marshy landscape is beyond saving, but you can actually make use of this space by starting your own bog garden in it. Of course, you don’t have to have an overly-moist patch of land to enjoy a bog garden. All you’ll need to create one is a little extra landscaping or container gardening.

Preparing a Bog Garden

Besides moisture, there are a few other things you’ll need to consider when picking out and preparing your site. For starters, you’ll want an area that gets about five hours of direct sunlight. All that light is exteremly beneficial for the plants that thrive in bog gardens. If you’re not sure how much sunlight a particular area gets, you can either use a meter to gauge it or just keep an eye on it during the day to get a basic idea.

Prepping the spot you pick is a bit more physically intensive than a lot of your other gardening chores. Begin by digging a hole that’s about two feet deep. You can make your hole as wide as you’d like your garden to be, but you must adhere to this depth. Once you’ve finished, use pond liner or a similar material to line the inside of the hole.

Since bog gardens rely on soil that toes a fine line between very moist and too moist, it’s essential to create some drainage holes in your liner. Only do this after you’ve got it perfectly in place. You’ll find it best to put these holes about a foot below the top of the larger hole you dug. Be sure to space them all out evenly as you go.

Try to keep about a foot of the liner above the hole. This material will gradually start to slide down as your bog garden settles after planting. Plus, any excess that doesn’t get brought down into the hole can always be hidden in by nearby landscaping. Use rocks or mulch to cover it up and keep it out of sight.

Next, you’ll put soil mixture into the hole. It may seem like a good idea to just use all the dirt you initially removed from the hole, but for an ideal growing environment, you’ll want to opt for some soil amendments instead. Try mixing coarse sand, peat moss, and compost into the soil you removed (wth an emphasis on the peat moss). This blend will give your bog garden the nutrients and drainage it needs to thrive.

Once you’ve gotten your bog garden ready for planting, you’ll want to leave it alone for about a week. During that time, all you’ll have to do is keep it well-watered and let it settle. After the week is up, it’s time to plant some seeds.

Perfect Plants for Your Bog Garden

Your bog garden should be filled with plants that feel more at home in wet climates. The good news is that there’s a wide variety of plants out there that fit that bill. Iris pseudacorus, Rodgersia pinnata, Astilbe chinensis, Gunnera manicata, and Salix alba “Vitellina” are all excellent choices.

Carnivorous plants can be especially fun to cultivate in bog gardens. Kids and adults alike can get a real kick out of growing things like pitcher plants and Venus flytraps. Depending on the weather in your area, you may also want to grow these in a container bog garden.

As with any garden, you’ll want to try to layer your bog garden based on your plant’s respective heights and growing seasons to keep it looking great all year long.

Mini Bog Garden

You may not have the space to create a large bog garden in your backyard, or you may not be up to the full preparation and maintenance of one. If either of those are true for you, consider starting a small container bog garden instead. Just about any container will work, but some may require the same pond liner you’d use in an outdoor setup. Potential containers include hard plastic wading pools, rubber tubs, and barrel planters.

A bog garden can make a fun and unique addition to any backyard, especially if a piece of it is already a little marshy by nature. Sometimes, making your yard work for you just takes a few extra steps.

How to make a bog garden for wildlife

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As well as creating biodiversity, the moisture-loving flora of the bog can look utterly spectacular. “These are colourful and dramatic species,” says Trevor. “They are great fun to play with, growing big and tall and making a real statement.”

Yellow iris, a beautiful native bog plant. © Iain Sarjeant/Getty

Bringing a touch of boggy splendour to your garden is easier than you might think. Late summer to early autumn is the best time to begin, as your bog will be able to establish itself before winter, and the plants will have the best possible start in spring.

A bog garden works equally well adjacent to a pond or on its own. Naturally damp clay soils are ideal, but you can create wet habitat in free-draining soil if you use a liner and introduce topsoil. You can even make a mini-bog in a container – half a barrel lined with plastic is all you need to bring a slice of this extraordinary and lively habitat into your back yard. Find out more at www.plantlife.org.uk

If you’d rather build a pond, take a look at this how-to guide instead:

How to build a wildlife pond

Photo © Steven Wooster/Getty

How to create a bog garden

1

Plan your bog garden

Mark the outline using a rope or hose on sunny, level ground away from overhanging trees. “As with any wetland site you need as much sun as possible – at least six hours a day,” says Trevor.

2

Dig a big hole

Dig a hole 50–100cm deep, placing the soil to one side. Line the hole with a butyl liner and pierce with a fork for drainage (remember, you are not making a pool but an area of wet soil).

3

Add a bog substrate

You can add a 3cm-layer of grit or gravel over the liner to help prevent the soil from blocking the drainage holes, but it’s not essential. The water will eventually find its way through.

4

Backfill the hole

Fill the hole and trim back the liner. Mix in just a small amount of old compost – too many nutrients will result in too much leaf, making your bog garden hard to control.

5

Add some bog plants

Plant up with nectar-rich, moisture-loving plants and water thoroughly while they get established, then leave the area to become naturally waterlogged over winter.

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6 top tips for making a bog garden

  • Plant a combination of the short (eg water avens, creeping jenny) for ground cover and the tall (eg flag iris) for perches. Do mix it all up a bit, though – there are no rules.
  • Avoid pendulous sedge for height – it can get very aggressive (use flag iris, purple loosestrife and meadowsweet instead), and gunnera – it can get very big.
  • Think about the flowering year. Marsh marigold blooms in spring, for example; yellow flag iris in summer and hemp agrimony in early autumn.
  • Water your bog in drought (but respect hosepipe bans). It’s worth burying a leaky hose around the edge and connecting to your main hose.
  • Bog species can be vigorous, requiring annual maintenance. Include a few flat stones to step on while snipping – this will prevent the soil from compacting.
  • Allow your bog plants as much space as you can. “These are large plants with big roots and they need plenty of water,” says Trevor. “You want to create a reservoir of moisture low down in the soil and avoid having to top it up – if the area is too small it will dry out quickly.”

A bog garden is an area of permanently moist (but not waterlogged) soil. It may be that you can exploit existing poor drainage in your garden, or you can artificially create the correct conditions using pond liners to trap water in the area so that it mimics natural bog garden conditions.

A miniature bog garden in a tin bath

Attract wildlife

One of the best ways of attracting wildlife to your garden is by providing water.

If you worry about the safety of a garden pond then a bog garden will make the perfect alternative and will be just as valuable to wildlife.

Like a pond, bog gardens will quickly become home to lots of insects and invertebrates, making it a perfect feeding spot for frogs, toads, hedgehogs and birds. Dragon flies may be spotted perching on taller grasses and with careful plant selection it will be easy to attract butterflies and bees.

Creating a bog garden

Making an artificial bog garden is very similar to making a garden pond as you have to start by digging!

  • Mark out the outline of your bog garden with dry sand, string or a garden house. If it looks like your bog garden is getting big then you may need to position some stepping stones for access.
  • Dig out to about 5cm (18 in) deep, keeping the excavated soil to one side.
  • Line the hole with thick polythene or flexible butyl pond liner and puncture it several times at 1m (3ft) intervals. (Although you want the soil in your bog garden to be moist, it shouldn’t be completely waterlogged or it will starve your plant roots of oxygen and they could rot)
  • Fill in with a thick layer of coarse grit or gravel to prevent the drainage holes from becoming blocked.
  • Replace the excavated soil back into your bog garden, mixing in plenty of organic matter such as leaf mould or well-rotted manure.
  • Allow the soil to settle for a week before planting and watering in well. To keep your bog garden well-watered consider lying a soaker hose over the soil surface and disguise it with a layer of mulch. This can then be attached to a hosepipe or irrigation system.

Create a miniature bog garden

If you would like to create a bog garden on a much smaller scale then you can easily use a container. Large plastic pots (with no drainage holes or you’ll need a liner); half barrels and tin baths make perfect choices.

Adding a top mulch of gravel to the tin bath to help with filtration, water chemistry and add an aesthetic appeal

Fill the base of your chosen container with a layer of gravel and then add Perrywood potting soil to the top. Soak your container completely and allow the soil to settle for a week, keeping it wet. Plant your bog plants in their chosen position and top with more soil if necessary. Water well and mulch with a layer of gravel. Container bog gardens will tend to dry out more quickly so make sure they are checked for water frequently.

What to plant

When selecting plants for a bog garden you will have the opportunity to create wonderful displays with a range of contrasting foliage and lots of flower forms and colours.

Lobelia cardinalis ‘Queen Victoria’

Marginal plants that would typically be planted on a pond shelf are perfect choices. Just a few of the many possible examples include Caltha, Equisetum, Water Iris, Gunnera, Cyperus and Lobelia.

Moisture loving herbaceous perennials that will enjoy bog garden conditions include Lythrum, Hostas, Astilbe, Rheum, Ligularia, Primula and the Shuttlecock fern Matteuccia. Grasses such as Carex, Juncus and Acorus are also ideal.

Cyperus

Take care not to overcrowd when planting and make sure that you don’t put smaller plants between large ones as the smaller ones will struggle to attract sunlight.

Bog gardens

Bog gardens are a type of shallow pond garden, in which an area is permanently covered in a thin layer of water. It is ideal for an area of the garden that has poor drainage or it can be created from scratch by making a shallow type of pool.

Plants grown in a bog garden must be those that thrive having constantly wet roots and lower stems/leaves. It should also be situated in an area where it will not create an insect nuisance, such as near a house, windows/doors or play and leisure areas, as bog gardens attract flies, mosquitoes, gnats, midges, etc. However, provided the bog garden is carefully planted and situated, these insects and their larvae will instantly become a meal for amphibians, newts, birds and bats that frequent your garden. It will attract damsel flies, dragonflies and other lovely insects too, making for nice viewing and photo opportunities.

Bog gardens tend to be suitable for cool to mild temperate climate zones, many natural bogs are alpine, sub-alpine or cool climate, thus the plants suited to such gardens reflect the cooler temperature needs. The bog garden may not do well in a hot environment, if it risks attracting disease-carrying mosquitoes, in which case it would not be a desirable addition to a garden space unless well managed. If that is not an issue, base such a bog garden on tropical or sub-tropical plants suited to a watery growing environment.

Making a bog garden

Decide where to situate the garden. It could be in an area of the garden or yard with poor drainage or perhaps alongside an existing pond or body of water.

If the area is without a watery surface, create one by building a shallow pond. This pond should only be about 20cm deep at most. If the soil is especially heavy, place gravel onto the pond liner, to aid drainage, and be to poke holes in the liner. Finish with a layer of soil over the top, then add the water.

Plants suitable for bog gardens

Choose plants that grow in a water environment naturally. Here are some suggested plants:

  • Butterworts (Pinguicula)
  • Bladderworts (Utricularia)
  • Pennyroyal (Mentha pulegium)
  • Meadowsweet (Filpendula ulmaria)
  • Marshmallow (Althaea officinalis)
  • Teasel (Dipsacus fullonum)
  • Ragged robin (Lychnis flos-culculi)
  • Hemp agrimony (Eupatorium cannbinum)
  • North American pitcher plants (Sarracenia)
  • Lady’s smock (Cadamine pratensis)
  • Purple loosestrife (Lythrum salicaria)
  • Sundews (Drosera)

See also

  • Wikipedia, Bog garden, at https://en.wikipedia.org/wiki/Bog_garden (additional plant suggestions are listed here)

10 plants to grow in bog gardens

If you have a boggy or very wet area in your garden, why not create a bog garden?

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Plant towering gunnera for dramatic green architecture, then underplant with purple loosestrife to attract wildlife. For a touch of elegance, complete your border with the snowy-white blooms of zantedeschia, which will keep flowering all summer long.

If your garden conditions aren’t completely suited to the growing requirements of a particular bog plant, don’t be put off. Wetter areas can be created by digging up damp soil and placing a plastic liner underneath with holes puncturing it, to retain some drainage. If an area is too wet, you could build some simple raised borders with timber or stone within the bog.

Related content:

  • Get the best from wet soil
  • How to plant candelabra primulas
  • Get the best from acid soil

Browse our pick of 10 plants for a boggy spot, below.

Shorter plants like astilbe are great for underplanting around larger plants like gunnera.
1

Gunnera manicata

The huge, thick architectural leaves make a statement at the back of a boggy site. Fold the dead leaves over the crown in the autumn to protect it.

Huge leaves of gunnera 2

Ligularia

Ligularia have large serrated leaves, with a mahogany underside. The tall yellow flower spikes are perfect for adding drama to a boggy border.

Yellow flower spikes and serrated leaves of ligularia 3

Iris pseudacorus ‘Variegata’

The upright, sword-like leaves of Iris pseudacorus ‘Variegata’ are marked with creamy-white stripes. Bright yellow flowers appear in May. Though less vigorous than the uncultivated species, be sure to divide it in spring.

Bright-yellow iris flowers 4

Zantedeschia aethiopica

For a more sophisticated boggy border, try Zantedeschia aethiopica. Glossy-green arrow-shaped leaves are set off by stately spathes of white flowers, with prominent yellow spadices. Semi-evergreen, so cut it back in winter if the leaves die.

A swathe of white calla lillies 5

Rodgersia pinnata

Frothy, pink-white flowers and fabulous, huge, horse chestnut-like leaves, make Rodgersia pinnata a must-have in sites with poor drainage.

Pale-pink flowers and bold leaves of Rodgersia pinnata 6

Lythrum salicaria

A tough perennial with upright stems and long-lasting flowers. Plant purple loosestrife if you’re looking to attract birds and bees to the garden.

Purple loosestrife flowers 7

Astilbe chinensis

Shorter plants like astilbe are great for underplanting around larger plants like gunnera. Their divided leaves and fluffy plumes of purple or pink flowers really add impact to borders.

Magenta astilbe plumes 8

Cornus alba

When the lush growth of the warmer months has fallen away, the bright red stems of Cornus alba are a reliable source of winter colour. Cut back old, dull stems in spring to encourage the growth of vibrant new ones.

Vivid pink dogwood stems 9

Salix vitellina ‘Britzensis’

For further winter interest, grow Salix vitellina ‘Britzensis’ for its golden-yellow stems. Like C. alba, cut in back in spring for colourful new growth.

Golden stems of willow ‘Britzensis’ 10

Typha minima

The small reed mace has fine foliage and classic bulrush-type flowers. Unlike its larger relative Typha gracilis, the smaller T. minima won’t take over wet borders.

Advertisement Miniature bulrush-type flowers of small reed mace White flowers of meadowsweet

More bog plants to grow

  • Eupatorium cannabinum
  • Filipendula ulmaria
  • Onoclea sensibilis
  • Osmunda regalis
  • Candelabra primulas
  • Ranunculus spp.
  • Hemerocallis spp.
  • Iris laevigata

Bog gardens can be a fascinating addition for children and adults in the home landscape. Carnivorous pitcher plants (Sarracenia), butterworts (Pinquicula), sundews (Drosera), and other colorful and interesting wildflowers can be easily grown in cultured conditions. Many of these wetland plants are fairly small in size and suitable for patio containers or wet garden areas.

The most important element in the location of a bog garden is providing adequate sunlight. Bog plants require full sun for at least six hours a day. In addition, these plants will perform best in a moist, acidic soil with plenty of water during the growing season.

Building a Bog

An easy way to establish bog plants is to take advantage of an existing wet sunny area on your property. Road ditches, gutter runoff areas, pond edges and overflows, muddy areas, and waste treatment systems are often neglected places that could be planted to provide interest.

To build a bog garden on a dry site, dig a shallow area around twelve inches deep and place a quality pond liner along the bottom. Be sure to poke large holes along the sides of the liner to allow the bog garden to drain. Many bog gardeners make the mistake of not providing adequate drainage which can create stagnant water conditions, and the plants will not grow.

For a soil medium, use an 80% coarse peat moss and 20% sharp sand combination. Wet the mixture thoroughly and it will be ready to plant. Bog gardens can also be successfully grown in the shallow areas of small pools and ponds. Place the plants with the top of the container just at or slightly above the water surface.

Container Bogs

Smaller bog gardens can be easily created with containers. Use a container at least eight inches deep and twelve inches wide. Use the same soil mix as described above. Place a saucer underneath the pot and keep filled with water to allow the soil medium to stay moist. Smaller containers are difficult to maintain as they dry easily.

Bog plants are surprisingly easy to grow if provided the correct conditions, and will delight you and your family for years to come. Recommended Bog Plants:

COMMON NAME

SCIENTIFIC NAME

FLOWERING

Colic root

Aletris lutea

Yellow summer flowers

Red milkweed

Asclepias lanceolata

Red summer flowers

Swamp sunflower

Helianthus angustifolius

Yellow fall flowers

White-topped sedge

Dichromena colorata

White summer flowers

Lady’s hatpin

Eriocaulon decangulare

White summer flowers

Yellow candyroot

Polygala lutea

Yellow summer flowers

Balduina

Balduina uniflora

Yellow summer flowers

Joe-pye

Eupatoriadelphus fistulosus

White fall flowers

Cardinal flower

Lobelia cardinalis

Red fall flowers

Pine hibiscus

Hibiscus aculeatus

White summer flowers

St. John’s wort

Hypericum brachyphyllum

Yellow summer flowers

Blazing star

Liatris elegans

Purple fall flowers

Pine lily

Lilium catesbaei

Red summer flowers

Publications may download photo at 200 d.p.i.

These factsheets were written by Robert F. Brzuszek, Assistant Extension Professor, The Department of Landscape Architecture, Mississippi State University.

Bog Gardens

Have you ever thought about having a bog garden? It means that you can grow a wider range of plants, especially if your topsoil is quite sandy (see types of topsoil article here). It’s a particularly good way of using an old pond, but you can also make a new bog garden using pond liner. Autumn or winter is a good time for this project, so it will be ready for planting in spring.

Making the bog garden

You can use an old plastic pond as the base, or buy some butyl pond liner. If your pond is already in place, then all you need to do is drain it and clean it out. Otherwise, you will need to dig a hole. Mark out the area with string. You will have to dig it out to about 45cm/18in, so make sure it’s not too large. Keep the soil as you dig it out, as you’ll need it later.

Once the hole is ready, then line it with pond liner, weighted down at the edges with stones or bricks, or put in the old pond. Pierce the bottom of the hole or the liner at intervals for drainage. Line the bottom with a layer of gravel or grit, to improve drainage.

If you dug out your own hole, now is the time to return the soil. If you used an old pond, you will need to buy topsoil, available from topsoil suppliers. If you need gravel too, it’s probably a good idea to order them together to save money on delivery! Let the soil settle naturally over several weeks, and top up as and when necessary before planting. Keep it weed-free over winter until you’re ready to plant.

Suitable plants

There are a wide range of plants suitable for a bog garden, ranging from ordinary perennials that are quite happy in moist soils, such as hostas, through to genuine marginals and pond plants like Pontederia and flag iris (Iris pseudacorus). As always when choosing plants, think about having some tall and some spreading, and also about your season of interest.

One word of warning: Houttynia ‘Chameleon’ or ‘Flame’ is a foliage plant often recommended for bog gardens. It is very pretty, with lovely red and green variegated leaves, but it will spread like mad in ideal conditions like a bog garden.

Ongoing maintenance

Your plants will need the usual maintenance in a bog garden: splitting after a few years, and so on. You will also need a way of keeping it damp. Either use a watering system, or incorporate a length of porous hosepipe in the base of the bog garden, with the end leading out to an easily-accessible point. You can then irrigate through it and keep the soil damp all year.

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