Native trees - general considerations
For information about specific species,
see our page on Native Tree Choices.
For every landscaping need, there are Northern Virginia native trees that will fit the bill. If you only have time to do one thing to turn your yard into a wildlife sanctuary, let it be to plant a native tree.
The benefits of trees in general are obvious: in addition to improving property values and providing shade and year-round beauty, trees cool the environment, soak up greenhouse gases, and provide fruits and shelter for birds and other wildlife. But trees that are native to our area go far beyond that. Unlike those from other continents, a tree that is native to Virginia can support astonishing numbers of Virginia native insects. And insects—especially caterpillars—are what songbirds feed their babies. No native plants, no caterpillars; no caterpillars, no baby birds. And no butterflies either, of course!
A tree is the perfect way to honor or memorialize a person or event.
Details about growing conditions and wildlife value of individual species can be found in the Native Plants for Northern Virginia guide and app.
Eastern Redbud (Cercis canadensis)
Arlington's champion White Oak (Quercus alba)
A tree for every yard
A tree of any size will cool the air, sequester carbon and support wildlife. Small understory trees work in small yards or where there are overhead lines. Large canopy trees provide even more benefit if you have the space to plant them.
Spring blooms are the most prominent features of several understory trees.
Spectacular fall foliage can be reason enough to choose some trees.
Various bark textures provide winter interest.
Edible fruits are fun, though it may be a decade or more before the tree produces any. See the page on Edible Native Plants.
Trees have large, extensive root systems that reach beyond the canopy, so make sure you have room for them.
As with all plants, trees need to be given the right amount of sun and moisture to flourish, and some will tolerate salt or soil compaction better than others. Most require acid or neutral soil, but a few can tolerate alkaline. Check the pH of your soil - you can get an inexpensive pH meter at garden centers.
A deciduous shade tree on the west side of a building will significantly reduce air conditioning costs while allowing winter sun for warmth.
Plan around obstacles
In locations that might obstruct a view, choose a tree with one dominant leader so that the lower limbs can be removed if necessary as the tree grows.
Plant at least 15 feet from buildings.
Consider the overhead wires and clearance for cars and pedestrians. Find distance guidelines here.
Call Miss Utility first and don’t plant a tree right over your sewer pipes or gas lines.
Avoid tree litter on walking surfaces
Trees with small leaves that shed over a long period are often preferred next to parking lots.
Acorns and other nuts may be problematic on sidewalks.
Choose the right size tree
Use small trees in small spaces. This may seem obvious, but you need to plan for the root spread and not just the height. Tree roots need 1 to 2 cubic feet of non-compacted soil volume for every square foot of expected crown area spread. Typically the soil area provided should be about a third less than the mature canopy area. This means that planting in a little square that is cut out of pavement is problematic except for the smallest trees. You'll need to choose in that situation between a small tree with a normal life expectancy of maybe 30 years, or a large tree that will also die after about 30 years after obtaining about the same height that an understory tree would have reached. As a strategy for greening some urban spaces, this may be the best you can do: you just plan to replace the trees periodically. For details about the myriad considerations for planting street trees, see this website.
The shape is important as well. Some trees can be planted near walkways or streets, but others have branches that are too near the ground.
In a small space, you can also use large shrubs that have been arborized, meaning trained when young into a tree shape. Examples include Blackhaw Viburnum (Viburnum prunifolium) and Witch Hazel (Hamamelis virginiana), but any shrub that can tolerate light on its trunk could be trained this way. Some shrubs such as Staghorn Sumac (Ruhus typhina) and Common Elderberry (Sambucus canadensis) make nice small trees, but you would need to keep cutting back suckers.
Did you know?
94% of caterpillars that use trees as their food source complete their life cycle by falling to the ground and burrowing in the leaf litter over winter? If you remove that leaf litter, you are at least in part defeating one of the main reasons to plant native trees. How about planting a layered landscape instead?
Options for a 10 x 15 foot parking lot island
Though more a shrub than a tree, any Sumac would do well in those conditions.
Small trees that would be suitable include
Amelanchier species - single stem specimens, not 'Autumn Brilliance'
Carpinus caroliniana (but not if salt is an issue or soil is compacted)
Chionanthus virginicus (if its width is not a problem
These are taller trees that could do well until they outgrow the space after 20 years or so, at which point they may need to be replaced.
- If width is not a problem
- Better shape for walking under
Willow oak (Quercus phellos)
Maximizing ecological benefits
The more plant species in an area, the more animal species will be supported and the less vulnerable the trees will be to diseases and pests.
The bigger the territory, the more species of insects, birds and other wildlife a natural area can support. You can expand the habitat value of nearby natural areas by planting the trees that grow there as a plant community. We are hoping to soon be able to provide you with plant lists to help you figure out the plant communities nearest you.
When plants reproduce sexually, meaning by producing flowers that get pollinated and go to seed, the offspring are unique individuals. Just as combinations of genetic traits result in differences between one human being and another, there are distinct differences between trees of the same species. Having a diversity of genetic traits provides resilience in the face of diseases, pests and changing climate. By contrast, cultivars are produced by cloning, which reduces biodiversity.
A tree that evolved in Florida or Oregon will not be as adapted to our region as another tree of the same species that evolved right here.
Plant a grove
The more trees, the better! Trees normally grow close to each other, with their roots interlocking, which provides stability. The best way to ensure that trees won't fall over is to plant them close together. Trees also communicate through an underground network, providing nutrients to each other and helping fend off attack from pests. If you have room, plant them in groves, spaced at 10 foot intervals. If that seems too close together, take a look at the woods - this is how they grow naturally, meshing their canopies and roots. Planting them all at once keeps them from shading each other out. This is also the best time to incorporate most shrubs into the grove.
Fringe tree (Chionanthus virginicus)
Oaks are the host plant to hundreds of caterpillars including the Red Spotted Purple butterfly. Caterpillars are the main food source for baby songbirds.
Because oaks hold onto their leaves in winter, many insects lay their eggs on them. When the larvae hatch in spring, Worm-eating Warblers and other songbirds descend on the leaves to feast.
Oak catkins attract wasps, caterpillars and aphids which in turn are a magnet for warblers.
Oak leaves of various species are the hosts for 150-200 species of leaf miners.
When to plant
Fall planting has many advantages, as the roots can to start to establish before the summer heat and droughts start. Spring planting is preferable for some slow-to-establish species, such as Baldcypress, American Hornbeam, Magnolia, Sweetgum, Tulip Tree, willows, and Willow Oak. Conifers prefer the warm soils of summer or early fall.
Choosing the specimens
Trees do not like to grow in pots. A seedling that is growing in your yard already and that is getting enough sun is the most likely to prosper. Otherwise, buy the youngest example you can find, as that tree within a few years will exceed in growth and health of a more expensive, larger tree planted at the same time.
Inspect the plant carefully. The top should be healthy with a good structure, and the trunk should be free of wounds (unwrap it to check), but the roots are the potential trouble-makers. Do not buy it if the roots are growing out the bottom holes. Probe the soil – there should be large roots coming out from the plant near the surface. Carefully remove it from the pot – garden centers should expect you to do this – and make sure the roots are white or tan and there are no large roots at the edge of the pot. If several trees in pots are sitting in a group, do not buy the ones on the edge that are receiving direct sunlight: sun heats up black plastic and kills roots.
Ask the garden center if the tree was produced by air pruning, a superior method which prevents the formation of encircling roots.
Victim of a mulch volcano
The Tree Benefit Calculator, developed by Casey Trees, allows anyone to make a simple estimation of the benefits individual street-side trees provide. With inputs of location, species and tree size, users will get an understanding of the environmental and economic value trees provide on an annual basis.