How to identify and control the invasive tree of heaven in forests

tree of heaven

When an owner has a written forest management plan, one of the common recipes for making a forest healthier is to control invasive species. Some common invasive species found in forests include rose multiflora and non-native honeysuckle.

Another common invader that I often find along the edges of fields or disturbed areas is the tree of heaven. The scientific name of the tree of heaven is Ailanthus altissima. When talking to foresters or any other forestry professional, they will use the name Ailanthus or tree of heaven.

According to Penn State Extension, the tree of heaven was first introduced to the East Coast in the 18th century. It was prized for its extremely fast growth and its ability to grow almost anywhere. Young shoots can grow to about 10 feet in a year if site conditions are good. This rapid growth and ability to adapt to most site conditions has caused tree of heaven to become a major tree pest.

The tree of heaven is also known to secrete a chemical into the soil that is toxic to surrounding plants, which can help reduce competition for resources and lead to low plant diversity in a forest.

where to find it

Although tree of heaven does not grow well in shady areas, it does take advantage of sunnier rights-of-way, trails, and other forest clearings. It will take over these areas very quickly by cloning itself through root sprouting. These buds can be shipped up to 50 feet from the tree.

Tree of Heaven colonies will include both “male” and “female” trees. The females produce up to 300,000 seeds each year. During the fall, the seeds will be red in color and turn brown during the winter. The female tree of heaven will often cling to the seeds from her for much of the winter season.

how to identify it

The tree of heaven resembles some native plants such as sumac and black walnut. To identify the tree, look for the smooth edges of the leaflets. Native trees will have jagged edges.

Tree of Heaven will also produce a foul odor when the leaves or twigs are crushed. The leaf scars on tree of heaven are very large and the twigs will have a fluffy brown center. The bark of the tree will have vertical stripes and will be a soft brownish-green when the tree is young.

When the tree is older, the bark will resemble the exterior of a cantaloupe in both color and texture. Older bark will still have those distinctive vertical stripes.

Impact

In addition to Tree of Heaven’s negative impact on native tree populations, it can also produce negative impacts on human health. Landowners should be careful when walking or treating the tree of heaven. The tree produces a chemical in its sap that can cause inflammation of the heart muscle if it gets into the bloodstream through an open wound. The tree also produces a lot of pollen and is a source of allergy problems for some.

Unfortunately, I have found the tree of heaven through many Ohio woods. It is especially easy to spot when driving on state roads.

If you find it

If a homeowner finds this tree on their property, I urge them not to cut down the tree. Cutting the tree down will simply cause the tree to send warning signals to the roots and cause bud break.

Contact The Ohio State University Extension for advice on chemical treatments. Penn State Extension also has great treatment tips on their website: https://extension.psu.edu/tree-of-heaven. If you think you may have a Tree of Heaven on your property but are unsure, contact your ODNR Division of Forest Services forester or your local SWCD office for help with identification.

The spotted lanternfly really likes tree of heaven as a host plant, so be careful to check any of these particular tree species found for signs of the invasive insect.

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