Planting-distance tool

Pick a species and tick what is near the spot: a house, a septic field, a sidewalk or driveway, power lines, a property line or another tree. For each one, the tool gives the distance in feet and the rule that sets it. Add the distance you have in mind for any of them, and a verdict says whether it fits, is tight or rules the spot out. Every rule is shown with its source, beginning with the tree's own page. These are rules of thumb, not a survey, and a town's own setback rules come first.

Species Its mature height and crown width set most of the distances.

What is near the spot Tick each one. Measure along the ground from where the trunk will stand, and add the feet if you know them.

House or other building

Septic tank or drain field

Sidewalk or driveway

Overhead power lines

Fence or property line

Another tree Which tree it is Not in the list? Pick one of about its size, or leave it as the same species.

Distances update as you change them.

The tool needs JavaScript. These are its rules, and the tree's own page comes first wherever it gives a figure. House or wall: the distance its page gives, or else half its mature crown, never under 15 feet for a tree, from University of Maryland Extension. Septic tank or drain field: at least the tree's mature height, from University of Georgia Extension. That is never under 10 feet for a shrub or 20 for a tree, the floors of Clemson Cooperative Extension. Between them, the two name willows, poplars, elms, birches, beeches, magnolias and red and silver maples as trees to avoid near a drain field. For those the tool asks three times their mature height, which is its own reading. Sidewalk or driveway: the distance its page gives, or else 10 feet for a tree under 20 feet tall and 20 feet for a taller one, from University of Maryland Extension. Iowa State Extension's least between trunk and pavement is 2 feet for a tree under 30 feet, 4 under 50 feet and 6 for a larger one. A shrub keeps half its crown from the edge, the tool's own reading. Power lines, by the International Society of Arboriculture's zones: within 15 feet of distribution wires, a tree of 20 feet or lower. From 15 to 50 feet out, a tree of 40 feet or lower. From 50 feet out, any tree. Property line: half the mature crown, so the crown stays on your side, the tool's own reading, and a town's own rule comes first. Another tree: the spacing its page gives, or else one crown width, the distance at which two crowns touch. For two different species, half of each tree's figure is added. Three quarters of the figure suits a grove, where crowns meet. The halves and the three quarters are the tool's own reading.

How far, and how to measure

Measure from the trunk. Measure along the ground from where the trunk will stand to the nearest point of each thing. That is the wall, the edge of the pavement, the nearest drain line or the tank, a point under the wires, the fence and the other trunk.
The crown sets most distances. Half the mature crown is how far the branches reach on each side, so the spread decides how close a tree can go to a wall, a line or a walk.
The tree's own page comes first. Where its How to grow section gives a distance from a wall, a walk or another tree, the tool takes that figure, so the two never disagree.
Keep trees off the drain field. Woody roots can clog and break the drain lines, which may lie only 6 inches down. A lawn or another shallow-rooted cover belongs over the field, and trees stay back from it.
A drain field needs sun. Trees that shade it heavily slow the drying the field depends on.
Under wires, choose by mature height. A tree that outgrows its zone is cut back by the line crew for the rest of its life.
Give a street tree its strip. A tree of 40 feet or lower wants a strip at least 4 feet wide between the sidewalk and the curb, and a taller one more than 8.
Call 811 before you dig. It is the national call-before-you-dig number. Call a few business days ahead, so the buried lines are marked with paint or flags.

The house rule is the planting-site check's, from University of Maryland Extension's Planting Trees in Our Changing Climate: "Plant small trees a minimum of 15’ away from the foundation." It adds: "A specific way to calculate spacing is to find out the expected mature canopy size of your tree, and cut that number in half." Where a tree's page gives no crown width, the tool estimates one from its height as the site check does. That is as wide as tall for a shrub, 0.9 of the height for a small tree, 0.8 for a medium one and 0.7 for a large one. The wire zones are the International Society of Arboriculture's, from its 2021 brochure Avoiding Tree & Utility Conflicts. Its low zone runs 15 feet either side of distribution wires and takes trees of 20 feet or lower at maturity. Its medium zone, 15 to 50 feet out, takes 40 feet or lower, and its tall zone, from 50 feet, any tree. A spot exactly 15 feet out counts as the medium zone, as on the planting-site check. Maryland's page allows a taller tree under wires: "Choose trees that are 25’ tall or lower at maturity." Virginia Cooperative Extension draws its low zone 20 feet from the line, for trees of up to 25 feet. The tool follows the stricter figures of the International Society of Arboriculture, as the site check does.

The septic rule comes from two extension services. University of Georgia Extension writes: "A good rule of thumb is to use the ultimate mature height of the selected tree as the minimum planting distance from the septic drainfield, then increase the distance." Clemson Cooperative Extension estimates that "tree roots spread out one to three times the height of the tree". It sets two floors: "Shrubs with less aggressive root systems should never be planted any closer than 10 feet and small less aggressive trees no closer than 20 feet from the drain field." Clemson also names the trees to avoid: "Trees with very aggressive root systems that should be avoided include willows, red and silver maples, beeches, birches, elms and poplars." Georgia's list adds magnolias and leaves out beeches. For a tree on either list the tool asks three times its mature height, the far end of Clemson's estimate, and that choice is its own reading. Georgia notes that drain lines are often shallow, "some no more than 6 inches from the surface", and Clemson that "the drain field needs sun to perform optimally". University of Florida IFAS Extension and the University of Minnesota's septic program keep trees and shrubs of any kind off and away from a drain field, and set no distance. The tool follows Georgia and Clemson, which give one.

Iowa State Extension sets the least room between a tree and pavement where space is short, as between a sidewalk and the curb. A tree under 30 feet tall needs "two or more feet between the trunk and any pavement or structure", one under 50 feet four, and a larger one six. Where there is room, University of Maryland Extension puts a tree under 20 feet at least 10 feet from a driveway and a larger one 20 feet away. The tool takes Maryland's figure as the distance that fits and Iowa State's as the least, and it reads a sidewalk as Maryland reads a driveway. Maryland's native landscape designs space a small tree about 20 feet from a building or sidewalk, more than its driveway figure for a tree under 20 feet. The tool keeps the driveway figures, which go by the tree's height. The strip widths are the International Society of Arboriculture's. No source gives a shrub a distance from pavement, so a shrub keeps half its crown from the edge, which is the tool's own reading.

At a fence or property line the tool takes Maryland's half crown, so the crown stays on your side, and that reading is its own. A town's own setback rule for trees, if it has one, comes first. The next tree takes the spacing its own page gives, or the mature crown where the page gives none, since two crowns touch at maturity one crown width apart. Three quarters of the figure, the room of a grove where crowns meet, counts as tight. For two different species, the tool adds half of each tree's figure. The halves and the three quarters are the tool's own reading. 811 Before You Dig, the national call-before-you-dig line of the Common Ground Alliance, asks for a call a few business days before any digging.

These are rules of thumb, not a survey or a permit. Your town, your utility and your septic permit may set distances of their own, and theirs come first. Small native trees and large shrubs for a small yard covers placing a tree near the house, the wires and the septic field. Six trees not to plant near a house names the trees that cause trouble there. Tree roots run shallow and wide explains how far roots reach. Native street trees covers the strip by the street and the wires over it.