What is tree-of-heaven?

Tree-of-heaven identification matters more than ever in Pennsylvania, because this fast-growing tree from China is the preferred host of the spotted lanternfly. It was planted in Philadelphia in the late 1700s as an ornamental and has since spread along roads, rail lines and vacant lots across the state.

The PA Department of Agriculture lists it as a Class B noxious weed. It grows several feet a year, tolerates poor soil and pollution, crowds out native trees, and spreads by both seed and aggressive root suckers.

Tree-of-heaven identification: what to look for

• Leaves: alternate and compound, 1 to 4 feet long, with 10 to 40 lance-shaped leaflets. Each leaflet has smooth edges except for one or two small, rounded teeth near the base, each with a gland on the underside. That gland tooth is the key feature.
• Smell: crush a leaf or snap a twig and it gives off a strong, rank odor many people compare to rancid peanuts or burnt popcorn.
• Bark: smooth and greenish-brown on young stems, turning light gray with pale, netted lines, like the skin of a cantaloupe.
• Twigs: thick and stout, with large heart-shaped leaf scars and a spongy, light brown pith inside.
• Seeds: female trees produce big clusters of twisted, papery winged seeds, 1 to 2 inches long, that turn tan or reddish and often stay on the tree into winter.

Where it grows in Pennsylvania

Tree-of-heaven is common statewide, including along highways and railroads through central PA. It grows anywhere it gets sun: road shoulders, field edges, woods openings after logging, fence rows, abandoned lots, and cracks along building foundations and retaining walls.

On home properties it often starts along a back fence, a driveway edge or the side of a garage, then spreads by root suckers into the yard. One female tree can release a huge amount of seed each year, and the papery seeds ride the wind well beyond your property line. Root suckers can pop up many feet from the parent tree, even on the other side of a fence or walkway.

Tree-of-heaven look-alikes

Several native trees have long compound leaves. Check the leaflet edges first.

• Staghorn sumac has toothed leaflets all the way around, fuzzy twigs and upright, cone-shaped clusters of red fruit.
• Black walnut has finely toothed leaflets and a pleasant, spicy smell, and drops round green nuts.
• Hickories and ash have fewer leaflets, usually 5 to 11, with toothed edges. Ash leaves are opposite each other on the twig.

Smooth leaflet edges with a gland tooth near the base and a bad smell add up to tree-of-heaven.

How to get rid of tree-of-heaven

Here’s the mistake most people make: cutting it down. Penn State Extension notes that cutting or mowing alone makes it send up many new sprouts from the stump and roots, so you can end up with a thicket where you had one tree.

Hand and mechanical:

• Pull small seedlings when the soil is moist, getting the entire root. This works only on young seedlings, not on root suckers attached to a bigger tree.
• Don’t cut established trees unless they’re also being treated with herbicide. For a tree that’s a hazard, the extension approach is to treat it first, wait about a month for the herbicide to take effect, then cut.
• Clip off seed clusters on female trees you can reach to slow spread while you plan treatment.

Cultural: after the trees are controlled, replant with native trees and shrubs to shade the ground, and check for new sprouts each summer.

Herbicides: Penn State recommends treating from July 1 until fall color begins, when the tree is moving sugars down to its roots. Glyphosate and triclopyr are the main active ingredients used, applied as foliar sprays on smaller stems, basal bark sprays on stems under about 6 inches, or the hack-and-squirt method on larger trees. Treatments outside that late-summer window tend to only damage the top. For a dense stand, the usual sequence is a foliar treatment on the thicket first, then basal bark or hack-and-squirt on the stems that survive. Plan on follow-up the next year for survivors. Read and follow the product label every time; the label is the law. Check that the product is labeled for your site, whether that’s a lawn, a landscape bed, woods, a roadside or ground near water, where only aquatic-labeled products belong. Applying herbicide for hire in Pennsylvania requires a PA Department of Agriculture pesticide applicator certification, so bigger jobs belong with a licensed lawn-care or vegetation-management company.

Keeping it from coming back

Expect some sprouts in the year or two after treatment, and watch for seedlings from neighboring trees. Catching them small saves a lot of work.

Because spotted lanternflies feed heavily on tree-of-heaven, controlling it near your house can help reduce lanternfly pressure on your property. If you see lanternflies, check the PA Department of Agriculture’s guidance on reporting and quarantine rules in your county.

Keep in mind that dead tree-of-heaven trunks get brittle, so trees that have been treated and left standing near a house, driveway or power line should come down once they’ve died back rather than being left to fall on their own.

Questions we get about tree-of-heaven

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