Selecting Trees For Wet Sites

Wet, poorly drained soils - soggy soils - are one of the most challenging soil types for growing plants in the landscape.

This is where water may stand for long periods of time or where drainage is slow. Except in times of extended drought, the soil here stays damp. If the site is also shaded, you may also find moss growing. These sites may be naturally occurring or man-made. A man-made situation can occur when run-off from pavement, roofs, sidewalks, etc., flood a site with excess water. If the soil is heavy clay and compacted then it doesn’t drain well and becomes soggy.

As a rule, plants don’t like to have their roots wet for extended periods of time. In wet soils, too much water fills the soil pore spaces resulting in low oxygen levels. When oxygen is lacking, water and nutrient uptake stops and trees begin to decline or die.

However, some species have adapted to tolerate persistently wet conditions. You may have noticed the “knees” produced on bald cypress trees when growing in or around water. The “knees” help with air absorption into the roots. Willow trees can produce new air-filled roots to replace roots killed by excess moisture. And some trees produce tiny bark openings called lenticels to serve as breathing pores, allowing air into the interior of roots and branches.

Wet, poorly drained soils can limit your plant palette but your choices don’t have to be boring.

Many of the trees adapted to wet soil conditions are native to Virginia. Some have great fall color, others have fragrant blooms, a few attract wildlife and they are all very tough plants.

Sweetbay Magnolia, Magnolia virginiana, common throughout coastal Virginia, is a small native tree with sweet-smelling bay-like leaves often found in moist woodlands and along streams and swamps. Sweetbay is noted for its 2 to 3 inch wide creamy white and lemon-scented flowers which begin blooming in June and continue sporadically through summer. It is considered a semi-evergreen although it will behave as a deciduous tree in colder zones or during colder winters. Its leaves are bright green on top with a frosted white color beneath. Sweetbay prefers moist soil, an acid site and full sun to part shade.

New Guide Available for Virginia Riparian Native Trees and Shrubs!

Swamp White Oak, Quercus bicolor Willdenow, is one of our most outstanding native oaks. Growing to 50-60’ tall with an upright oval outline, it is an excellent shade. This long-lived species is tremendously adaptable and once established, it is tolerant of both wet and dry soils. Swamp White Oak prefers moist-acid soil environments. Summer foliage is a dark glossy green with a bit of yellow in the fall. This oak is common in the northern Piedmont (Culpeper Basin) and infrequent elsewhere in the Piedmont and mountains (Ridge and Valley province only), rare in the Coastal Plain.

If you have a wet site, also consider the following list of trees that naturally thrive in such conditions. When selecting and planting trees for poorly drained sites start with small plants to allow them time to acclimate to the soil conditions. Successfully planting in wet sites is all about selecting the right plant for the right place.

Deciduous Trees for Wet Sites

Acer negundo, Box elder
Acer rubrum, Red maple
Amelanchier canadensis, Shadblow serviceberry
Betula nigra, River birch
Carpinus caroliniana, American hornbeam
Celtis occidentalis, Common hackberry
Diospyros virginiana, Persimmon
Ilex decidua, I. verticillata, Deciduous hollies
Liquidambar styraciflua, Sweetgum
Magnolia virginiana, Sweetbay magnolia
Nyssa aquatica, Black tupelo and Nyssa sylvatica Marshall, Black Gum, Sour Gum
Platanus occidentalis, American Sycamore
Quercus bicolor, Swamp white oak
Quercus nigra, Water oak
Quercus phellos, Willow oak
Salix nigra, Black willow
Taxodium distichum, Bald cypress
Ulmus alata, Winged elm and Ulmus americana L., American Elm

Evergreen Trees for Wet Sites

Magnolia grandiflora, Southern magnolia
Pinus taeda, Loblolly pine