- Trees And Water – Wet Soil Trees For Standing Water Areas
- Your Tree and Water Drainage
- Using Water Loving Trees to Correct Drainage Issues
- List of Standing Water and Wet Soil Trees
- Trees and Shrubs for Wet Soils
- How to choose the best trees for wet soils
- Some Like it Wet: Water-loving Trees
Trees And Water – Wet Soil Trees For Standing Water Areas
If your yard has poor drainage, you need water loving trees. Some trees near water or that grow in standing water will die. But, if you choose wisely, you can find trees that not only grow in wet, swampy area, but will thrive and may even help correct the poor drainage in that area. Let’s look at how to choose wet soil trees and some suggestions for trees to plant in wet areas.
Your Tree and Water Drainage
The reason some trees die or grow poorly in wet areas is simply because they cannot breathe. Most tree roots need air as much as they need water. If they do not get air, they will die.
But, some water loving trees have developed the ability to grow roots without needing air. This allows them to live in marshy areas where other trees would die. As a home owner, you can take advantage of this trait to beautify your own wet and poorly drained areas.
Using Water Loving Trees to Correct Drainage Issues
Wet soil trees are a great way to help soak up excess water in your yard. Many trees that grow in wet areas will use large amounts of water. This trait causes them to use up much of the water in their vicinity, which may be enough to dry the surrounding area out enough so that other plants that are not as adapted to wet soil can survive.
A word of caution if you plant trees in wet areas. The roots of most wet soil trees are extensive and can possibly cause damage to pipes (though not often foundations). As we said, these trees need large amount of water to properly grow and if they use up all the water in the wet area of your yard, they will seek water elsewhere. Normally in urban and suburban areas, this will mean the tree will grow into water and sewer pipes looking for the water it craves.
If you plan on planting these trees near water pipes or sewers, either make sure the tree you choose does not have damaging roots or that the area you will be planting in has more than enough water to keep the tree happy.
List of Standing Water and Wet Soil Trees
All of the trees listed below will flourish in wet areas, even standing water:
- Atlantic White Cedar
- Bald Cypress
- Black Ash
- Freeman Maple
- Green Ash
- Nuttal Oak
- Pin Oak
- Plane Tree
- Pond Cypress
- Pumpkin Ash
- Red Maple
- River Birch
- Swamp Cottonwood
- Swamp Tupelo
- Sweetbay Magnolia
- Water Tupelo
Trees and Shrubs for Wet Soils
Many trees and shrubs thrive in Iowa’s fertile, well-drained soils. Most trees and shrubs, however, don’t like wet soils. Fortunately, there are plants that tolerate wet soils better than others. The following trees and shrubs are good choices for wet sites.
The silver maple (Acer saccharinum) is commonly found along the banks of rivers and streams throughout Iowa. It is one of our largest native trees, growing up to 100 feet tall. Silver maples have been widely planted in the past because they transplant well, grow fast, and adapt to a wide range of site and soil conditions. Unfortunately, silver maples are weak-wooded trees. They often become liabilities in home landscapes because of their tendency to break apart in ice and windstorms. While the silver maple is a poor choice for the home landscape, it is suitable for windbreaks and natural areas.
River birch (Betula nigra) tolerates heat and drought better than the white-barked birches. It is also resistant to the bronze birch borer. The river birch is native to much of the eastern third of Iowa. It is typically found in moist to wet areas along rivers, hence the common name river birch. The exfoliating bark varies from gray-brown to reddish brown. The cultivar ‘Heritage’ has a salmon-white bark. River birches are often planted as multi-stemmed specimens or “clumps.” It grows 50 to 60 feet tall. River birches perform best in acid soils. Their foliage often turns a sickly yellow-green in alkaline soils.
The American hornbeam (Carpinus caroliniana) is native to woodlands in eastern Iowa. It is noted for its hard, tough wood. The American hornbeam is also referred to as ironwood, musclewood, and blue beech. The small, shrubby tree grows slowly to a height of 20 to 30 feet. It does well in heavy shade and wet soils, but will tolerate sunnier and drier sites. In the fall, the foliage turns yellow to orange red.
Another large, native tree is the hackberry (Celtis occidentalis). Though it can be found in a wide range of habitats, it is most often found in the floodplains of rivers and streams. Although hackberries don’t possess any outstanding ornamental feature, they are adaptable. They tolerate acid or alkaline soils, wet or dry sites, and harsh urban conditions. Hackberries usually grow 50 to 60 feet tall, but can grow 100 feet tall.
The green ash (Fraxinus pennsylvanica) is one of our most common native trees. It is also widely planted because of its adaptability and fast growth rate. The green ash grows well in both wet and dry soils. Its mature height is approximately 50 to 60 feet tall. Unfortunately, it is weak-wooded and susceptible to storm damage. Seedless cultivars, such as ‘Patmore’ and ‘Bergeson,’ are preferred for home landscapes. Another excellent cultivar is ‘Summit.’ ‘Summit’ has an upright growth habit, but does produce a few seeds.
One of our most distinctive native trees is the sycamore (Platanus occidentalis). Its large maple-like leaves, persistent seedballs, exfoliating bark, and huge size make it easy to identify. The sycamore is not a tree for a small yard as it may eventually reach a height of 75 to 100 feet. It is best suited to parks and other large open areas. Anthracnose (a fungal disease) is a problem in cool, wet springs. Severe anthracnose infestations cause heavy leaf drop in late spring.
Swamp white oak (Quercus bicolor) is a large, slow growing oak which may eventually attain a height and spread of 60 feet. While difficult to locate in nurseries, it is sturdy, drought tolerant, and makes a handsome shade tree. The swamp white oak performs best in moist, acid soils.
Originally found only in southeastern Iowa, the pin oak (Quercus palustris) has been widely planted across the state because of its pyramidal habit and ease of transplanting. Unfortunately, iron chlorosis is a serious problem in alkaline soils. Chlorotic foliage is a sickly yellow-green. The pin oak is not a good street tree because of its drooping lower branches. Fall color varies from bronze to red. It grows 60 to 70 feet tall.
Bald cypress (Taxodium distichum) is a deciduous conifer. Native to swamps in the southeastern United States, it does surprisingly well in the north. In Iowa, it performs best in the southern portion of the state. The foliage is an attractive yellow-green in the spring and turns to russet in the fall. The bald cypress possesses a pyramidal growth habit and may eventually reach a height of 50 feet.
Other trees that do well in wet soils include the cottonwood (Populus deltoides), alders (Alnus species), and willows (Salix species).
Red chokeberry (Aronia arbutifolia) is an upright, suckering, multi-stemmed shrub that grows 6 to 8 feet tall. Red chokeberry is noted for its red fruit in late summer and fall. Leaves turn a reddish purple in fall. The variety ‘Brilliantissima’ produces excellent fall foliage color (scarlet) and a large crop of glossy red fruit.
A native shrub, buttonbush (Cephalanthus occidentalis) is typically found along stream banks, lake shores, and other wet areas. The shrub has glossy green foliage and produces creamy- white flowers in globular heads in August. Its mature height is about 6 feet, though it can grow up to 12 to 15 feet in southern areas of the United States.
Although not widely planted, summersweet clethra (Clethra alnifolia) is an excellent shrub for the home landscape. It is native to wet areas and will grow in full sun or heavy shade. Summersweet clethra produces small, white, fragrant flowers on spike-like structures. The flowers appear in mid-summer and remain attractive for 3 to 4 weeks. Bees and butterflies find the flowers irresistible. The foliage of summersweet clethra is a lustrous, dark green. In the fall, the leaves turn to a pale yellow or golden brown. Plant size is variable and determined by soil and moisture conditions. Summersweet clethra can grow to 3 to 8 feet tall and 4 to 6 feet wide. The cultivar ‘Rosea’ produces pink flowers which fade to pinkish white. ‘Pink Spires’ produces rose- pink flower buds which open to soft pink.
Silky dogwood (Cornus amomum) is a native shrub commonly found along streambanks, wet prairies, and at the edges of bottomland woods. Silky dogwood produces flat- topped clusters of yellowish white flowers. Fruit is bluish with white blotches. Silky dogwood is a rounded shrub which grows approximately 6 to 10 feet tall with a similar spread.
Another native dogwood is redosier dogwood (Cornus sericea). It grows about 6 to 8 feet tall. The redosier dogwood is noted for its red-colored twigs in winter. Several varieties are available. ‘Cardinal’ is an introduction from the University of Minnesota Landscape Arboretum. Its twigs are bright red in winter. ‘Isanti’ and ‘Kelseyi’ are compact, red-stemmed shrubs. ‘Flaviramea’ has yellow stems.
Winterberry (Ilex verticillata) is a deciduous holly. The deep green leaves drop off in the fall revealing bright red fruit. The shrub attains a height of 6 to 10 feet. Hollies are dioecious. Male and female flowers are produced on separate plants. The cultivars ‘Sparkleberry,’ ‘Winter Red,’ and ‘Christmas Cheer’ produce abundant bright red berries. A male cultivar, such as ‘Southern Gentleman’ or ‘Jim Dandy,’ is required for pollination. Winterberries do require acid soils.
Purpleosier willow (Salix purpurea) is an 8 to 10 foot shrub. ‘Nana’ is a compact form which grows about 4 feet tall. ‘Streamco’ is a Soil Conservation Service, USDA introduction which was developed to prevent soil erosion along stream banks. The purpleosier willow is one of many willows that grow well in wet soils.
American elder (Sambucus canadensis) is a native suckering shrub that produces large clusters of purple-black fruit in late summer. The ripened fruit are good for jellies, preserves, and wines. The fruit are also attractive to birds. Its mature height is 6 to 10 feet. ‘Aurea’ and ‘Laciniata’ are two cultivars which have greater landscape potential than the species. ‘Aurea’ has golden-yellow foliage and red fruit, while ‘Laciniata’ has cutleaf foliage.
Virginia sweetspire (Itea virginica) and common sweetshrub (Calycanthus floridus) are two additional shrubs that do well in moist to wet soils.
When selecting trees and shrubs for the home landscape, gardeners should select plants suitable for the site. Wet sites can be a challenge. However, the aforementioned trees and shrubs will perform well in wet soils.
This article originally appeared in the August 7, 1998 issue, p. 108.
My window looks out on 9 Mile Creek, a rural looking creek in an urban/suburban environment in Minneapolis/St. Paul, Minnesota. In the six years our company has been here, this is the closest I’ve seen water come to the parking lot. For a number of weeks this spring and summer, the large ash trees on the 100 year floodplain were in standing water between one foot and three feet deep.
Below is a graph of Minnesota’s precipitation for the first half of 2014. Minnesota’s long-term annual average is 32.6 inches – as you can see we are almost there by June and the two wettest months of the year (July, August) have not yet passed.
A map from the early 2000s from the EPA predicted increases in very heavy precipitation (big storms) throughout the United States. The Northeast is predicted to have a 67 percent increase! Another map (looking like a patchwork quilt) from National Oceanic and Atmospheric Administration (NOAA) shows that most of Minnesota has had an increase in precipitation by up to 20 percent since 1900. The same increase or more is seen in Indiana, Michigan, northern Illinois and the northeastern United Stations. All but two patches of the Eastern United States (Central Florida and Central/Southern Appalachia) have had a 10 percent increase in rain. Minnesota and the upper Midwest are predicted to have a 33 percent increase in these larger storms. I think now is a good time to make a list of trees, shrubs and vines that can tolerate standing water
Map courtesy Environmental Protection Agency
Here are plants that I have seen with my own eyes growing in standing water (<3′) for weeks at a time and surviving well. Most were in a natural condition, but I also witnessed a few with long flood durations in urban settings. The list is Midwestern and Eastern North America centered, pretty much east of the 100th meridian. Most of these trees and shrubs are hardy into USDA Zone 5, but notably not Red Mangrove (USDA Zone 10). There are other folks who have seen different trees in standing water, so it’s not comprehensive, but these are ones I can personally vouch for. This is qualitative not quantitative data. Some of these trees are not native, or are weak wooded with bad branch attachments. Many are light on aesthetics; Gary Johnson, Extension Professor in urban forestry at the University of Minnesota fondly describes some of them as “Junkyard Dogs.” I don’t get to use that phrase nearly enough.
Thuja occidentalis – Northern White Cedar/Arborvitae (thrives in higher pH soils)
Salix Babylonica – Babylon/Weeping Willow
Taxodium distichum – Bald Cypress (takes briny water)
Salix nigra – Black Willow
Picea mariana – Black Spruce (thrives in lower pH soils)
Quercus macrocarpa -Burr Oak (Hard to believe, but there it was)
Fraxinus nigra – Black Ash (I wouldn’t plant because of Emerald Ash Borer)
Acer negundo – Box Elder (right now it has been in standing water for weeks, outside my office/Kestrel on 9 Mile Creek)
Populus deltoides – Dogtooth Cottonwood
Fraxinus pennsylvanica – Green Ash (I wouldn’t plant because of Emerald Ash Borer)
Larix laricina – Eastern Larch (thrives in lower pH soils)
Acer rubrum – Red/Swamp Maple
Rhizophora mangle – Red Mangrove (takes salty water)
Nyssa biflora – Swamp Tupelo
Quercus bicolor – Swamp White Oak
Alnus incana – Alder
Vaccinium angustifolium – Blueberry (thrives in lower pH soils)
Cephalanthus occidentalis – Buttonbush
Potentilla fruticosa – Bush Cinquefoil/Potentilla (thrives in higher pH soils)
Sambucus canadensis – American Elderberry (right now it has been in standing water for weeks, outside my office/Kestrel on 9 Mile Creek)
Amorpha fruticosa – Indigobush
Myrica pensylvanica – Northern Bayberry (thrives in low pH soils)
Salix exigua – Sandbar Willow
Hypericum perforatum – St. Johnswort
Symphoricarpos occidentalis – Western Snowberry
Vitis riparia – Riverbank Grape
Climate change scientists have shown that the largest fluctuations in extremes are occurring in the Northern Hemisphere in the northern temperate and boreal climates. Currently south central Minnesota, where the twin cities of Minneapolis-St. Paul are located is experiencing one of the wettest years ever. A few people (me included) are interested in these statistics, because there is a pattern here in Minnesota: Winter 2011 was our mildest in decades; Spring 2012 was our earliest spring in 50 years; Summer 2012 had a prolonged drought; Winter 2012 was long and the coldest in 20 years; Spring 2013 was much wetter than average; Summer 2013 was a record breaking drought; Winter 2013 was the coldest in 40 years and the snowiest in 20 years, and Spring 2014 was our wettest ever. If I was a betting man I would say that the pattern is more extreme versions of each season: wetter springs, colder winters, drier summers and rosier red falls.
My advice is to become familiar with trees that can tolerate wet conditions. We’ll all be needing them.
Peter MacDonagh, FASLA, ISA, is Director of Science + Design at The Kestrel Design Group.
Japanese Maple & other moisture-loving plants
A golden fullmoon maple (Acer shirasawanum ‘Aureum’ takes center stage in this in this moderately wet site.
Many of us in the Pacific Northwest deal with soggy clay soil, especially in spring. But there’s no need to let that put a damper on growing plants in wet places.
Sure, you can take the more expensive, mechanical approach with extensive drainage systems, dry creek beds or installing raised beds filled with imported garden soil. However, the easier and less expensive option is to utilize design tips for wet places, and to grow plant trees, shrubs and perennials with roots that can adapt to more soggy sites.
Degrees of wetness
There are many ways to transform a wet space from unusable to beautifully functional. But the key to making it work begins with understanding your site, its characteristics and seasonal conditions.
An area considered to be “soggy” is consistently wet and spongy with high water saturation. The soil is damp underfoot, but never swampy. Moderately wet sites have soil that is consistently moist but not waterlogged.
Areas that become saturated during the rainy season but reasonably dry out between rainfalls are considered intermittently or seasonally wet. This type of area may also be dry for several months once the rainy season is over.
Making the most of soggy sites
Besides rainfall, there are other factors that can contribute to soggy soil, especially if the growing area sits on a high water table or has soil that is heavy clay or drains poorly. If that soggy area sits in a shady spot protected from winds, it may remain wet or soggy year-round. Water from higher elevations and surrounding hardscapes — streets, driveways, rooftops — may collect in a low spot in the yard, resulting in soggy soil.
Wet areas such as these can provide a wonderful opportunity for creating high-impact designs. Turn a poorly drained, fairly sunny site into a wet meadow with appropriate bird- and butterfly-attracting wildflowers and grasses.
Is rainwater runoff an issue? A rain garden can utilize that runoff in a way that not only beautifies your space, but also benefits both wildlife and the environment. By employing a few rainscaping techniques, more water will filter into the soil or be contained for future use rather than being lost as runoff.
Low soggy areas and swales offer yet another opportunity for utilizing wet spaces. Swales between property lines or other low-lying areas offer an ideal environment for growing moisture-loving plants and grasses within the swale or along its edges.
Planting the swale with shrubs and perennials that tolerate wet soil will increase infiltration of nearby runoff into the soil. Of course, any low, soggy area also make the perfect spot for growing a wetland garden.
Style by design
Design ideas and strategies that work for other areas of a landscape apply equally well to gardens in wet places: combining plants in attractive groups, incorporating textural layers within the vertical space by arranging plants with good visual hierarchy, mixing a variety of colors and textures for visual interest, and finding a common thread that ties everything together through a consistent style.
Whether transforming a moderately wet space or a seasonally soggy area, the type and style of design you choose is best determined by the size of the area, how often and how long the area remains wet, the consistency of wetness (water depths and conditions may vary within the space) and the varying levels of sun and shade.
By putting all the pieces together, you will ultimately be better equipped to transform the problematic wet area in your yard into an asset with a purpose.
USE THE RIGHT MULCH
The best mulch for soggy sites will depend on your design aesthetics, availability, cost factor, plant needs and the pH of your soil. Mulch from shredded hardwood or wood chips helps to build the soil while suppressing weeds. Mulching with wood chips will help capture nitrogen runoff in the area. Pine-based mulches work well with acid loving plants and biodegradable textiles help prevent erosion on slopes and hillsides.
Gunnera and pieris shine beautifully in this moist, shady area of the garden.
Depending on the cause, wet areas may be quite soggy, moderately and consistently wet or intermittently or seasonally wet. Fortunately, there are plants that thrive in each of these conditions. Here are a few plant options to get you started.
Plants for soggy sites
buttonbush (Cephalanthus occidentalis), purple osier willow (Salix purpurea), scarlet rosemallow (Hibiscus coccineus), winterberry (Ilex verticillata)
Grass and rush-like plants:
Plants for moderately wet sites
Atlantic white cedar (Chamaecyparis thyoides), American hornbeam (Carpinus caroliniana), fringe tree (Chionanthus virginicus), green ash (Fraxinus pennsylvanica)
gunnera, hosta, ligularia, meadowsweet (Filipendula spp.), rodgersia, spiderwort (Tradescantia virginiana)
Plants for seasonally wet sites
American elm (Ulmus americana), hackberry (Celtis occidentalis), river birch (Betula nigra)
black chokeberry (Aronia melanocarpa), Fothergilla, Kerria japonica, pussyswillow (Salix discolor), summersweet (Clethra alnifolia)
bluestar (Amsonia tabernaemontana), butterfly weed (Asclepias tuberosa), Coreopsis verticillata, false spirea (Astilbe spp.), geranium, obedient plant (Physostegia virginiana), scarlet monkey flower (Mimulus cardinalis), tufted hair grass (Deschampsia cespitosa), western bleeding heart (Dicentra formosa)
Correction: Yellow Flag (Iris pseudacorus) is an Oregon class B noxious weed and was removed from this list.
How to choose the best trees for wet soils
Selecting the right trees for your site can be a daunting process, especially if you have the added issue of contending with difficult site conditions, as well as satisfying your tastes and styles. Selection of tree species to plant in areas prone to water logging or damp conditions is fairly limited, as there are only a number of trees that will tolerate this adverse condition. Generally trees need both oxygen and water blended in measure in which to thrive but in recent times too much rain has contributed to standing water and flash flooding where only the wetland group of trees are able to survive. Typically, for areas that get saturated for more than one week of the year the following Genus are best to plant; Alder, Willow, Poplar and Swamp Cypress. The following are our top 5 recommended trees for wet soils:
Alnus glutinosa (Alder)
Betula nigra (River Birch)
Populus tremula (Poplar)
Salix alba Tristis (Weeping Willow)
Taxodium distichum (Swamp Cypress)
Apart from the Swamp Cypress all of these can be planted as multi stems or standards and are a great way to lock up soils that may be prone to erosion. Multi stems are also great on windy sites as they are bottom heavy and are easy to establish without worrying about staking.
Don’t be tempted to go with any other genus on land prone to repeated waterlogging. Prunus, for example, will hate it and soon fail so beware, you can’t outwit Mother Nature! Choosing the wrong tree species for a water logged sites can have extremely detrimental results, as wet sites cause restriction in root productivity, root decay and even tree failure in very short periods of time. Therefore, choosing trees for your project that are tolerant of wet conditions from the offset is a great way of avoiding the disappointment of tree failure and ensuring that the trees you plant pass the test of time.
If you are tempted by alternatives, one thing you can do to aid planting succes is mound plant, i.e. planting with half of the container root system above ground level and mounding up the soil to cover it. By planting proud of ground level you are likely to give the root system greater and longer access to oxygen as the some of the root system will be above the water line.
When planting Barcham Trees you have the added benefit of immediate results following tree planting, as our unique container grown tree production method produces trees with a complete root system that will readily establish and continue to thrive from that point onwards. If you need any help or advice, please do not hesitate to contact our experienced tree team via chat, email or telephone.
Some Like it Wet: Water-loving Trees
In Colorado, we don’t have a whole lot of really wet areas. But those that are wet stay wet. The wonderful clay soil that we have all along the Front Range doesn’t allow water to drain through very quickly, so those low areas in yards or neighborhoods can be quite treacherous for plants. Below are some great trees of different sizes that not only can deal with, but thrive in these soggy areas.
Baldcypress is a tree that is native to the Southeastern United States in wetland areas. In our climate, it is a deciduous conifer, which means that it bears cones for fruit but will drop its needles in the winter. The needles on this amazing tree are a nice medium green and are extremely soft. The fall color is a striking golden-bronze color and the tree has shredded-looking red bark. This tree is very adaptable and maintains a tight pyramidal form. Winter watering is a must without significant moisture in the winter months. Baldcypress is a plant that will definitely set your yard apart from all of your neighbors.
Rocky Mountain Birch:
Rocky Mountain Birch is a plant known by many names; some of the most common synonyms are Water Birch and Rocky Mountain River Birch. This species is, however, distinctly different from the common River Birch of the Midwest and Eastern United States. Rocky Mountain Birch maintains its cherry-brown colored bark throughout its life. This tree is generally grown as a multistem tree or large shrub. Rocky Mountain Birch grows to a height of 20’ and will grow to be 15-20’ wide. This Colorado native grows naturally next to stream beds and creeks as it is a water loving tree. Rocky Mountain Birch gets fantastic golden-yellow fall color. Like the Bald Cypress, Rocky Mountain Birch will require winter watering without significant moisture in winter months.
Thinleaf alder, also known as Mountain Alder, is another Colorado native tree that is water-loving. This tree is another multi-stem tree that will grow to 20’ tall and 15’ wide. Thinleaf alder is closely related to Rocky Mountain Birch and has very similar culture and similar features. This plant features nice, dark green foliage in the summer and golden yellow fall color. The catkins (flowers) in the spring and fruit formed in mid-summer are great ornamental features of the thinleaf alder. If you want a beautiful large shrub or small tree to fill in a wet area of your yard, Thinleaf Alder is one of my favorites for those areas. Like the previous two plants mentioned, this species requires winter watering if there isn’t a significant amount of moisture in the winter months.