How to Kill Tree of Heaven and Stop the Suckers

Do not cut it first. Treat the standing tree with a systemic herbicide between July and the start of fall color, wait about 30 days, then cut it down. If you cut first, the root system responds with suckers, and you will have dozens of new stems instead of one tree.

That is the whole decision. The rest of this page is about which treatment fits which stem, and why the calendar matters more than the equipment.

Why cutting first fails

Tree of heaven spreads by root as well as by seed. Penn State Extension says established trees send up root suckers as far as 50 feet from the parent tree, and that a cut or injured tree may send up dozens of stump and root sprouts. The University of Maryland Extension puts it just as plainly: cutting the tree down will not eradicate it unless you take additional steps, because cut trees regrow from any roots left alive.

This is the expensive mistake the current search results let people make. A tree is cut because it is in the way. The stump looks dead. Then a ring of suckers appears, and the job is bigger than the tree that was cut.

Two related facts from the extension programs explain why the problem grows:

• Female trees can produce more than 300,000 seeds a year, and the winged seeds travel on wind and water.
• Sprouts as young as two years old can produce seed.

So a failed cut does not just make more stems. It can make more seed-producing stems.

Choose by stem size

One warning about the table: a cut-stump treatment is not on it. Penn State Extension says cut-stump herbicide applications do not prevent root suckering and should not be used on tree of heaven. The stump may stay clean while the roots send up suckers.

When to treat tree of heaven

The treatment window is mid- to late summer, from about July 1 until the onset of fall color. Both extension programs give roughly that window.

The reason is sap flow. In late summer the tree is moving carbohydrates down to its roots for winter. A systemic herbicide applied then moves with that flow and reaches the root system. Penn State Extension says applications outside that window injure aboveground growth but do not control the roots. The foliage may die while the roots stay alive.

The University of Maryland Extension adds a useful detail for homeowners: after a systemic treatment, it may take about a month before you can cut the tree without risking regrowth. That wait is part of the method, not a delay.

What the extension programs name for herbicide

Penn State Extension lists dicamba, glyphosate, imazapyr, metsulfuron methyl and triclopyr as effective on tree of heaven. For most treatments it recommends products containing glyphosate or triclopyr, because they have practically no soil activity and pose little risk to nontarget plants through root uptake. The University of Maryland Extension names glyphosate and triclopyr as commonly used systemic ingredients.

This page does not give rates or mixes. Product strengths differ, and the label for the product in your hand is the only rate that applies. Follow the product label; the label is the law. If the label and this page disagree, the label wins.

Two cautions from the sources:

• Foliar sprays can hit desirable plants. Penn State Extension limits foliar use to sites where you can cover the target without unacceptable contact with nearby plants.
• Basal bark and hack-and-squirt are targeted methods. They put the product on the stem rather than in the air, which is why they are used near plants you want to keep.

Protect yourself

Tree of heaven is not a touch hazard like poison hemlock, but it is not harmless either. Penn State Extension notes that it is a very high pollen producer and a moderate source of allergy for some people. It also reports skin irritation or dermatitis from contact with leaves, branches, seeds and bark, and rare reports of heart muscle inflammation after sap exposure through broken skin, blisters or cuts.

Wear protective clothing and gloves if you will have extensive contact, and keep sap off your skin. That is Penn State Extension’s advice, and it applies to the person running the saw as well as the person spraying.

After you cut

Expect to return. Both extension programs describe tree of heaven as a multi-year project.

• Watch the site for new suckers, especially within the first season after cutting.
• Treat regrowth while it is still small enough to reach.
• Check the whole clone, not just the stump. Penn State Extension describes tree of heaven as growing in dense clonal colonies, so the stems you see may belong to one root system.
• Keep the area clear of seed-producing stems. A female tree that survives will keep seeding the site.

Well-established stands are only eliminated through repeated effort and monitoring. Penn State Extension says initial treatments often only reduce the root system, which makes follow-up work necessary.

When to call a professional

Call an arborist or a licensed applicator if:

• The tree is large and close to a house, fence, driveway or power line.
• The tree is on a property line, or the stand crosses one.
• The infestation covers a large area, or the stems are too tall for safe coverage.
• You cannot treat it in the July-to-fall window and still need it down for safety.

A hazardous tree still gets the same order of work: treat first, wait, then cut. The difference is who does it.

Related WildScope pages

• Tree of heaven species profile for identification and look-alikes.
• Tree of heaven bark in winter for identifying it without leaves.
• Sumac vs tree of heaven before you cut a native look-alike.
• When to treat invasive plants for how the summer window fits the year.
• How to dispose of invasive plants for the material after cutting.
• Invasive plants in Pennsylvania for state rules and reporting.