How Do You Get Rid of Tree of Heaven in Pennsylvania?

Brinko Tree Service

3 hours ago

5 min read

You get rid of Tree of Heaven by killing the roots with a systemic herbicide first and cutting the tree down later, because cutting alone makes it come back thicker. Penn State Extension explains that when the tree is cut or mowed, it responds with large numbers of stump sprouts and root suckers, and it recommends herbicide treatments from July to the onset of fall color, when the tree is moving carbohydrates down to its roots. If a tree has to come down for safety, Penn State advises treating it first, waiting about 30 days for symptoms to develop, and then cutting.

Pennsylvania treats this tree as more than a nuisance. The Pennsylvania Department of Agriculture lists Tree of Heaven (Ailanthus altissima) as a Class B noxious weed, a category for plants that are widely established in the state and cannot feasibly be eradicated, and noxious weeds cannot be sold, transported, planted or otherwise propagated in Pennsylvania. This guide covers how to identify it, why cutting backfires, the treatment methods Penn State describes, and how to plan removal of a large tree.

How Do You Identify Tree of Heaven?

Tree of Heaven is an invasive tree with long compound leaves made up of many leaflets. Penn State Extension points to three features that separate it from native look-alikes such as staghorn sumac, black walnut and hickory:

Smooth leaflet edges. The native look-alikes have toothed, serrated leaflet edges, while Tree of Heaven leaflets are smooth.
Glandular teeth at the base. Each lance-shaped leaflet has one to two protruding bumps near its base.
The smell. Crushed leaves and other plant parts give off a strong, offensive odor.

It grows fast. Penn State says it can reach 80 feet tall and up to 6 feet in diameter, and a female tree can produce more than 300,000 seeds a year. Add the root suckers covered below, and one tree can become a stand. Rutgers University notes that a cluster of root suckers is made up of genetic clones of the parent tree, all male or all female, so a patch that spreads from a female tree can produce seed as well.

Why Does Cutting Tree of Heaven Make It Worse?

The root system is the problem. Penn State Extension notes that established trees continually spread by sending up root suckers that can emerge as far as 50 feet from the parent tree, and a cut or injured tree may send up dozens of new sprouts from the stump and roots.

Penn State is direct about the common shortcuts. Mechanical methods such as cutting or mowing are ineffective, and cut stump herbicide applications do not prevent root suckering and should not be used. The tree also releases allelopathic chemicals from its leaves, roots, and bark that can limit or prevent other plants from establishing, so a stand left alone tends to crowd out everything around it.

What Treatment Methods Does Penn State Recommend?

Penn State Extension describes three herbicide methods, all timed from July 1 to the onset of fall color:

Foliar spray using glyphosate plus triclopyr.
Basal bark treatment with triclopyr ester, applied to the lower trunk of stems up to about 6 inches in diameter.
Hack-and-squirt, where spaced cuts are made through the bark and filled with glyphosate or triclopyr. Penn State's guideline is one hack per inch of trunk diameter, with a minimum of two, leaving intact bark between the cuts.

Follow the product label for rates and safety equipment, or hire a licensed pesticide applicator. Since Penn State describes basal bark treatment for stems up to about 6 inches across, larger trunks are usually handled with hack-and-squirt. Penn State also notes a few reports of skin irritation from contact with the plant and rare reports of heart inflammation from sap entering broken skin, so wear gloves and long sleeves when handling it.

Expect more than one round. Penn State says well-established stands are only eliminated through repeated efforts and monitoring, so plan to check for new sprouts the following summer. Rutgers University's Plant and Pest Advisory gives a slightly later window of mid-July to mid-October, when the tree moves the most sugars down to its roots through the phloem and carries the herbicide the farthest. Rutgers also advises waiting at least 30 days after treatment before cutting, so the herbicide has time to reach the more distant roots.

How Is Tree of Heaven Connected to Spotted Lanternfly?

Tree of Heaven is a preferred food source of the spotted lanternfly, according to Penn State's Center for Private Forests. The Center published its Tree of Heaven control guidance with that connection in mind. Our post on how spotted lanternfly affects trees in Western PA covers the insect itself.

The same treat-then-cut approach applies whether your goal is lanternfly control or simply clearing an invasive stand. Cutting the trees without treating the roots first leaves you with more stems, not fewer.

How Should You Remove a Large Tree of Heaven?

Large trees near homes, driveways, sheds or power lines still need to come down safely once they are dead or dying. Here is the sequence that follows Penn State's guidance:

Have the tree treated with herbicide between July and the start of fall color.
Wait about 30 days for symptoms to develop.
Have the tree cut down and the brush chipped or hauled away.
Watch for root suckers over the next growing season and treat any that appear.

Grinding the stump clears the spot for lawn or planting, but it does not stop sprouts from the wider root system. That is why the herbicide step comes first. For more on leftover stumps, see what happens to a tree stump if you don't grind it. Tree of Heaven is not the only invasive tree Pennsylvania homeowners are removing, and why Bradford pear trees are being removed across PA is covered in another. If you are clearing a lot for building, which trees should be removed before building starts is worth a read before work begins.

FAQ

Is Tree of Heaven illegal in Pennsylvania?

It is regulated. The Pennsylvania Department of Agriculture lists it as a Class B noxious weed, and noxious weeds cannot be sold, transported, planted or otherwise propagated in the state.

Will cutting down Tree of Heaven kill it?

No. Penn State Extension says cutting and mowing are ineffective because the tree responds with large numbers of stump sprouts and root suckers.

When is the best time to treat Tree of Heaven?

From July 1 to the onset of fall color, according to Penn State Extension, when the tree is moving carbohydrates to its roots.

How long after treatment can the tree be cut down?

Penn State recommends waiting about 30 days for symptoms to develop before cutting a treated tree.

How is it different from sumac or black walnut?

Check the leaflet edges and the smell. Penn State notes that sumac, black walnut, and hickory have toothed leaflet edges, while Tree of Heaven leaflets are smooth with one or two glandular teeth near the base, and crushed Tree of Heaven leaves smell strongly unpleasant.

How far can the roots send up new trees?

Penn State Extension says root suckers can emerge as far as 50 feet from the parent tree. Rutgers adds that a large tree cut without herbicide treatment first can respond with potentially dozens of trunk sprouts and root suckers across that distance.

Tree Removal and Lot Clearing From Brinko Tree Service

Brinko Tree Service, based at 1010 Sunset Blvd in Harrison City, brings nearly 20 years of experience to properties across Westmoreland and Allegheny Counties. Once a Tree of Heaven has been treated and is ready to come down, Brinko provides tree removal, stump grinding, and lot clearing for overgrown stands, along with brush chipping and debris hauling. The company is fully licensed and insured, follows OSHA and ANSI safety regulations with an OSHA safety site supervisor on every job site, and offers free estimates.