Six trees not to plant near a house, and what to plant instead

None of these six trees is worthless; two are native and magnificent in the right place. The trouble is that the right place is not a small lot beside a house, a driveway, a sidewalk and a sewer line, and each has a specific, well-documented way of becoming a problem there. Every one was chosen because it grows fast and looks good in year three. The alternatives, all from our own catalog, are mostly slower, and that is the point. A tree that puts on wood slowly holds its limbs, keeps its roots in the ground, and is still there when the house changes hands.

Each of the six has one problem that shows up near a house, and each has a substitute that does the same job in the same space.

White mulberry: invasive, brittle, and it stains everything

The problem: white mulberry came from China for a silkworm industry that never took, and it has since spread across the East on its own and onto invasive plant lists across the region. Birds eat the fruit and plant seedlings in every fencerow and foundation bed. The wood is weak and the crown drops limbs. The fruit stains sidewalks, cars and shoes for weeks. The tree hybridizes with our native red mulberry and is slowly replacing it.

“Red mulberries are more selective about growing conditions and locations, but cross-pollination with white mulberries results in hybrids that are closer to the white species than the red.” (University of Maryland Extension, Invasives in Your Woodland: White Mulberry)

Instead: red mulberry, the native, has bigger leaves, longer and sweeter fruit and none of the invasive spread. Its fruit still stains, so give it a spot at the edge of the yard where the birds can have the mess. For fruit near the house with less of a carpet under it, an American persimmon holds its fruit until after frost.

Lacebark elm: handsome bark, weak crotches, escaping seedlings

The problem: lacebark elm was planted widely because it shrugs off Dutch elm disease, and its mottled bark is genuinely handsome. But it grows fast into a crown of narrow, weak crotches that split in ice and wind. It seeds heavily in the fall. In the Southeast especially, those seedlings are escaping into the woods and putting it on invasive-plant watch lists.

Instead: American hornbeam gives you a small, tough tree with smooth, sinewy gray bark that is at least as interesting, orange-red fall color, and no seedlings in the neighbors’ beds. On dry ground, hop hornbeam is the same idea with shreddy bark and fine, elm-like texture.

Willows: brittle wood and roots that find your drain lines

The problem: a weeping willow is a pond tree, and a beautiful one, as long as the pond is far from anything you own. Willows use enormous amounts of water and send roots toward it wherever it is, which means drain lines, septic fields, footing drains and any cracked sewer lateral within reach. The wood is brittle, so the tree sheds twigs every week and limbs every storm, and most weeping willows are in decline by forty or fifty. A wet corner with room is the place for one; a wet corner by the house is not.

Instead: black gum takes wet ground and dry ground alike, has the best scarlet fall color in the East, feeds bees for weeks in spring, and lives for centuries instead of decades. Bald cypress is the other choice for a spot that floods, and on a lawn it rarely makes knees, which are one of the open questions in how floodplain trees survive high water.

Silver maple: fast wood, split forks, lifted pavement

The problem: silver maple is native and grows faster than almost anything, which is why it lined every postwar street. Fast growth means weak wood; the tree forks into co-dominant stems with bark trapped between them, and those forks split. Its roots run along the surface, heave sidewalks and driveways, and find old clay sewer pipes. And it gets huge, seventy feet and more. In a floodplain it is a fine tree. Next to a foundation it is a slow argument with the house.

Instead: for a mid-sized shade tree, yellowwood reaches thirty to fifty feet, carries hanging white flower clusters in late spring, has smooth gray bark and roots that behave. For something that will still be standing in three hundred years, black gum again.

Tuliptree: magnificent, and far too big for a small lot

The problem: tuliptree is native, grows straight and fast, and in a woodland it is one of the tallest and most beautiful hardwoods in the East. It is also far too big for a small lot, well over a hundred feet with time. It drops limbs in wind and ice. In a dry year it sheds flowers, leaves and seed all summer. The aphids that colonize it rain sticky honeydew on whatever is parked or set beneath it, and black sooty mold follows. With a back acre, plant one and thank yourself in thirty years; with a patio, plant something else.

Instead: cucumber magnolia is the choice for someone with room for a big, fast tree. It is a straight, fifty-to-eighty-foot native magnolia with huge leaves and knobby fruit that turns scarlet for the birds. It grows two to three feet a year on good soil. For the flowers-and-honey side of a tuliptree on a lot that cannot take one, sourwood blooms in July, feeds bees, and turns crimson in September. It does so at half the size, in a bed rather than a lawn strip.

Callery pear: banned in a growing list of states, and it splits

The problem: Bradford, Cleveland Select, Aristocrat and the rest are all Callery pear. The cultivars cross-pollinate, birds spread the fruit, and the thorny wild offspring have taken over old fields and roadsides from Pennsylvania to Texas. The branch unions are so weak that a typical Bradford splits in half at fifteen to twenty-five years old. The flowers smell like a fish market. Several states now ban its sale, and more are considering it.

“Additionally, the ‘Bradford’ cultivar is extremely susceptible to damage from storms due to branches having narrow crotch angles; these trees will also split under their own weight after 15-20 years of growth.” (USDA National Invasive Species Information Center, Callery Pear)

Instead: serviceberry does everything people wanted from a Bradford pear. It has white flowers in early April before the leaves, a tidy fifteen-to-twenty-five-foot crown and orange-red fall color. It also bears a June crop of sweet fruit the robins and waxwings will race you for. Most people who come to Blue Whale Trees asking for a Bradford pear go home with a serviceberry instead. Blackhaw is the choice for a dry, tough spot; white fringetree for a wet one; flowering dogwood for shade.

Where to plant a shade tree to cool a house

A shade tree cools a house most on the west side, where it blocks the hottest sun of the day, from about 3 to 7 p.m. in summer. The east side comes next, shaded from about 7 to 11 a.m.

The south side is better left open for the winter sun. A tree there shades the house in summer only once its crown reaches over the roof, and in winter it blocks the low sun that warms the house. A deciduous tree lets much of that sun through once its leaves fall, but its bare branches still cast a good deal of shade. A tree to the south belongs at least 2.5 times its mature height from the wall, and one to the southeast or southwest about four times.

For a tree that will reach 25 feet or more, advice on saving energy puts it 10 to 20 feet from the east or west wall. A wide crown needs more room than that: the rule for any tree near a house is half its mature crown width, and never under 15 feet. To shade a two-story house, choose a tree that will reach 30 feet or more. These four trees we grow will reach it, each set at the distance its crown needs:

• Black gum: 20 feet from the house. Zones 4 to 9, 40 to 70 feet.
• Yellowwood: 25 feet from the house. Zones 4 to 8, 30 to 50 feet.
• Swamp white oak: 30 feet from the house. Zones 3 to 8, 50 to 60 feet.
• Northern red oak: 40 feet from the house. Zones 3 to 8, 50 to 75 feet.

Shading the air conditioner’s outdoor unit saves little, under 3 percent by one estimate. Shrubs crowding the unit cut its air flow, so keep every plant at least 3 feet from it.

The rule

Match the mature size to the space, the moisture to the site, and the species to the region, and most of the problems above never come up. The tree finder sorts the catalog by those same three, plus sun and hardiness zone. For a tree you already have in mind, the site check tests it at the distance you have, starting from a yellowwood 25 feet from a wall.

Common questions

What trees should you not plant near a house?

White mulberry, lacebark elm, willows, silver maple, tuliptree and Callery pear. Each has one documented fault near a house, from roots in the drain lines and forks that split to seedlings in every fencerow.

How far from a house should a tree be planted?

Half the tree’s mature crown width is the usual rule, never under 15 feet for a tree, and some trees ask for more. A black gum takes 20 feet, a white oak or bur oak 40 and a black walnut 50, and a site check at the distance you have settles it for one species.

Is Callery pear banned?

In a growing list of states, Pennsylvania among them, and more are considering it. Where it is still sold, a serviceberry does everything people wanted from it without the splitting.