Choosing the tree location
There are several considerations when siting a tree.
Street trees
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.
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
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Amelanchier species - single stem specimens, not 'Autumn Brilliance'
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Carpinus caroliniana (but not if salt is an issue or soil is compacted)
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Chionanthus virginicus (if its width is not a problem
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Magnolia virginiana
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
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Ilex opaca
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Juniperus virginiana
- Better shape for walking under
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Nyssa sylvatica
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Quercus velutina
River Birch has interesting bark
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Essential needs of the tree
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Available soil volume
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Avoiding obstacles
Human considerations
Aesthetics
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Flowers
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Spring blooms are the most prominent features of several understory trees.
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Fall color
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Spectacular fall foliage can be reason enough to choose some trees.
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Bark
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Various bark textures provide winter interest.
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The view
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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.
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Fruit
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Edible fruits are fun, though it may be a decade or more before the tree produces any. See the page on Edible Native Plants.
Cooling
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A deciduous shade tree on the west side of a building will significantly reduce air conditioning costs while allowing winter sun for warmth.
Pedestrians and vehicles
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Trees with small leaves that shed over a long period are often preferred next to parking lots.
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Acorns and other nuts may be problematic on sidewalks.
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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.
Tree or shrub?
A tree is something you walk under, and a shrub is something you walk around!
But...
In a small space, you can 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 (Rhus typhina) and Common Elderberry (Sambucus canadensis) make nice small trees, but you would need to keep cutting back suckers.
Possumhaw (Viburnum prunifolium)
with Golden Ragwort (Packera aurea)
Essential needs of the tree
Sun and moisture
It is critical to choose a tree species that is adapted to the amount of sun and moisture at the site. It is easy to overestimate the amount of sun in a given location - this should be measured as the number of hours of direct sun after the nearby trees have leafed out. Keep in mind that canopy trees create shade, but only a few of them can themselves grow in the shade. See the details on the Native Tree Choices page.
Tulip Poplar planted by George Washington
Available soil volume
Trees need 1.5 cubic feet of uncompacted soil for every square foot of mature tree canopy. This translates very roughly to about one third fewer square feet than the area of the expected canopy (the expectation being that your uncompacted soil may be at least two feet deep). With insufficient volume, as is often seen in parking lots, the tree's growth will be stunted and life expectancy greatly shortened.
For example: a White Oak's expected minimum canopy spread is 50 feet (radius 25 feet), therefore a canopy area of 3.14 x 25 x 25 = about 2000 square feet. If your soil is two feet deep, allow an area of 1/3 less than that, or about 1300 square feet. So for instance, a yard with 44 x 30 feet of space will do, though these are minimums and more would be better. Normally, many tree roots would spread well beyond the crown, and the soil in your lawn may be quite compacted, in which case you may need to double these allowances.
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50+ foot spread - allow at least 1300 square feet - White Oak, Swamp White Oak, Scarlet Oak, Northern Red Oak, Southern Red Oak, Chestnut Oak, Chinquapin Oak, Black Oak, American Sycamore, Shagbark Hickory
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40+ foot spread - allow at least 1100 square feet - Red Maple, Hackberry, Sweetgum, River Birch, American Beech, Swamp Chestnut Oak, Pin Oak, Post Oak, Bitternut Hickory, Mockernut Hickory
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30+ foot spread - allow at least 600 square feet - Willow Oak, Shumard Oak, Black Willow, Tulip Poplar, Pitch Pine
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25+ foot spread - allow at least 410 square feet - Black gum, Flowering Dogwood, Redbud, Hophornbeam, American Persimmon, Sassafras, Green Hawthorn
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20+ foot spread - allow at least 270 square feet - Virginia Pine, Shortleaf Pine, White Pine, Paw Paw, American Hornbeam, American Holly, American Hornbeam, Blackjack Oak,
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15+ foot spread - allow at least 150 square feet - Fringe Tree, Serviceberry, Eastern Red Cedar, Chickasaw Plum
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10+ foot spread - allow at least 70 square feet - Sweetbay Magnolia
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8+ foot spread - allow at least 45 square feet - American Plum
Avoiding nearby obstacles
Houses - plant trees at least 15 feet away from buildings
Sidewalks - the roots of maples, willows and Sweetgum are more likely to damage sidewalks
Underground utilities - Call Miss Utility but be aware that there may be other underground pipes that they don't mark, such as sewer and water lines.
Never plant trees or shrubs within 5 feet of an underground power line.
Overhead wires -
Dominion's recommendations
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0-15 feet from the line: No trees. Shrubs under 20 feet tall at maximum growth.
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15-30 feet: Small trees allowed (20-45 feet, with the taller trees in this range recommended as you progress away from the power lines)
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30+ feet: Large trees allowed.
NOVEC's recommendations
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0-25 feet from the line: Only shrubs and small trees under 15 feet at maximum growth. (There are many native shrubs but no native trees that stay this short.)
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20-50 feet: Under 40 foot trees
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50+ feet: Large trees allowed
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Transformer boxes: Keep shrubs at least 10 feet away from transformer doors and 4 feet away from the sides.
Examples of NOVA native shrubs under 15 feet
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Aronia arbutifolia Red Chokeberry
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Aronia melanocarpa Black Chokeberry
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Baccharis halimifolia High Tide Bush
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Ceanothus americanus New Jersey Tea
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Cephalanthus occidentalis Buttonbush
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Cornus amomum Silky Dogwood
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Cornus racemosa Gray Dogwood
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Eubotrys racemosus Fetterbush
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Euonymus americanus Strawberry-bush
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Hydrangea arborescens Smooth Hydrangea
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Hypericum prolificum Shrubby St. John's Wort
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Ilex verticillata Winterberry Holly
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Itea virginica Virginia Sweetspire
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Kalmia latifolia Mountain Laurel
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Lindera benzoin Spicebush
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Morella pensylvanica Northern Bayberry
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Physocarpus opulifolius Ninebark
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Rhododendron periclymenoides Pinxter Azalea
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Rhododendron prinophyllum Early Azalea
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Rhododendron viscosum Swamp Azalea
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Rhus aromatica Fragrant sumac
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Rhus copallinum Winged Sumac
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Rhus glabra Smooth Sumac
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Rosa carolina Carolina Rose
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Spiraea alba Meadowsweet
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Staphylea trifolia Bladdernut
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Vaccinium corymbosum Highbush Blueberry
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Vaccinium pallidum Early Lowbush Blueberry
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Viburnum acerifolium Maple-leaved Viburnum
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Viburnum dentatum Arrow-wood Viburnum
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Viburnum nudum Possum-haw
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Viburnum prunifolium Blackhaw viburnum
Examples of NOVA native trees under 40 feet
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Amelanchier arborea Downy Serviceberry
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Amelanchier canadensis Shadblow Serviceberry
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Amelanchier laevis Allegheny Serviceberry
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Asimina triloba Pawpaw
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Carpinus caroliniana American Hornbeam
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Cercis canadensis Eastern Redbud
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Chionanthus virginicus Fringe Tree
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Cornus florida Flowering Dogwood
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Crataegus viridis Green Hawthorn
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Magnolia virginiana Sweetbay Magnolia
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Ostrya virginica Hophornbeam, Ironwood
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Prunus americana American Wild Plum
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Prunus angustifolia Chickasaw Plum
It's too bad to see trees get mangled.