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Green Scene: Some plants will welcome boggy soil created by recent snowstorms

By Joel M. Lerner
Saturday, February 27, 2010; E01

As I write, snow is finally melting, making its way into the soil, creating soggy conditions in planting beds and woodlands.

Already this winter, we've set a record for snowfall in the Washington area, so boggy conditions going into spring are to be expected. The result of this supersaturated soil is that some of you may find it necessary to become bog gardeners, working in an area that is soft and muddy.

Consistently wet conditions can be a nuisance, making lawns hard to mow, leaving muddy tracks through turf areas and even causing grass to die because oxygen isn't available to the roots. There are many trees, shrubs and perennials that will not flourish in these wet conditions.

Trees with saturated root systems can topple because the absorption roots of even large trees anchor them only two feet into the soil. Root-rot diseases, mildew and mold are common during cool, moist weather, and compaction will occur from the weight of ice and snow and tramping by wildlife and gardeners.

There are a host of plants that will thrive in these conditions, however. Some species don't evenmind being planted in standing water. For example, blue flag iris and acorus thrive in water, but they require sun to flower or display showy variegated foliage.

Other plants, such as ferns, that like moist conditions will perform better in shady areas. Lightening the soil with leaf mold and planting all trees, shrubs and perennials high -- leaving as much as one-third of the roots aboveground -- will help plants drain and let oxygen get to the roots. Here are some flora that will thrive in soggy conditions:

Trees

Weeping willows are a romantic choice, but they are notoriously thirsty, prone to canker and other diseases, and will root toward any water source, including septic systems. Traditional weeping willows (Salix babylonica) are beautiful but too large for most gardens -- up to 70 feet tall by 40 feet wide -- and their branches weep to the ground.

Red maple (Acer rubrum) is a good choice, as is sweet bay magnolia (Magnolia virginiana). One of my favorite trees, serviceberry (Amelanchier arborea), tolerates moist conditions and has edible berries and striking orange-red fall foliage.

If you're looking for a tall, stately tree that loves water, the common baldcypress (Taxodium distichum) is a possibility. It's a deciduous conifer that displays russet-red fall needles and grows slowly to 75 feet or more.

River birch (Betula nigra) is another graceful tree that has whitish tan, exfoliating bark offering tremendous winter interest.

Bitternut hickory (Carya cordiformis) will grace moist-to-wet woodlands and offers beautiful golden fall color and nuts, sap and foliage that attract wildlife.

Atlantic white cedar (Chamaecyparis thyoides), a native evergreen with soft blue-green foliage, thrives in moist conditions and offers many hybrids.

Shrubs

Red osier dogwood (Cornus sericea) is a great choice for sunny spots, offering white flowers, white berries that birds love, and red or yellow stems that provide winter interest. Several varieties also display white variegated foliage in summer.

Elderberry (Sambucus canadensis) and highbush blueberry (Vaccinium corymbosum) like moist conditions and have edible fruit. Some people make wine from elderberries.

A shrub that loves wet feet, and is shade tolerant and valued by birds and homeowners for its brilliant red winter berries, is the deciduous winterberry holly (Ilex verticillata).

The smaller pussy willow (Salix caprea) is ornamental, with its soft male catkins (flowers) appearing in March and early April if the plant is grown in full sun.

American euonymus (E. Americanus) and spicebush (Lindera benzoin) will do well in shady, wet conditions. American euonymus has a brilliant red fruit.

Spicebush is the sole habitat for the spicebush swallowtail butterfly, and it emits a spicy fragrance when the bark or foliage is bruised.

Virginia sweetspire (Itea virginica) loves wet feet, has fragrant flowers and magnificent fall color, colonizes and becomes a fuller plant in sun than in shade.

Perennials

Perennials that tolerate boggy conditions are astilbes, which offer shrublike foliage with feathery, plumed flowers, and the native, grassy-looking sweet flag (Acorus calamus) that resembles large flag iris and releases a pleasant cinnamon scent when bruised.

Japanese irises (I. ensata) have showy purple, blue or white flowers and beautiful foliage all summer, and blue flag iris (I. versicolor) has long flat leaf blades, growing to a height of one to two feet.

New England aster (A. novae-angliae) needs partial-to-full sun and wet feet to flower purple-violet from late summer into fall, offering nectar and seeds for wildlife.

Bigleaf ligularia (L. dentata), rodgersia (R. species) with huge foliage, and the huge-leaved butterbur (Petasites species), some with leaves four feet across, will do well in shade and crave wet soils. Joe-pye weed (Eupatorium purpureum) has huge pink flowers, grows four to seven feet tall and is a butterfly magnet. It does best in sun.

Most ferns like moisture, and some thrive with wet feet, such as the evergreen wood fern (Dryopteris marginalis), which creates colonies in shade, and the ostrich fern (Matteuccia struthiopteris) with its tall shuttlecock appearance and fiddleheads that are used in gourmet cooking. There are grasses and sedges that flourish in wet circumstances. These include black-flowering sedge (Carex nigra), with bluish leaves and blackish flowers in late spring; wood oats (Chasmanthium latifolium) native to bogs and marshes in eastern North America, and the tall native switch grass (Panicum virgatum), which grows best in full sun -- and strongly in the summer heat -- and is a natural for the edge of pools or ponds.

Wool grass (Scirpus cyperinus), a member of the sedge family, is a very ornamental native of wet meadows and swamps in northeastern North America and grows to five feet.

If these bog plants have piqued your interest, try some in your garden this spring, especially if soggy conditions persist.

Joel M. Lerner is president of Environmental Design in Capitol View Park, Md.

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