Although beautiful from afar, a Tree of Heaven can be problematic. In North America, the Tree of Heaven (Ailanthus Altissima) is considered to be an invasive species, due to its ability to shade out native trees. The female Tree of Heaven can produce as many as 300,000 seeds per year, all of which are dispersed by wind alone. With the Tree of Heaven’s quick growth rate, it consistently outcompetes native plants for sunlight, and when it wins, it forms dense colonies that cover the plants below it, causing them to deteriorate.
Since the Tree of Heaven is considered undesirable, it’s important to identify it from other trees. Similar-looking trees such as species of ash trees, hickory trees, and walnut trees, can be distinguished from the Tree of Heaven by the differences in leaflet shape, the fruits of the trees, or by seeds they produce.
Below, we will go over the look-alike species that you may find, how to identify them, and how to get rid of the Tree of Heaven if you spot one on your property. So, keep on reading to find out more!
Where Does The Tree Of Heaven Grow?
The Tree of Heaven was introduced from China to North America in the late 1700s. First seen in Pennsylvania, the Tree of Heaven is considered ornamental as it’s aesthetically pleasing, although very ugly to nearby vegetation. The Tree of Heaven has since spread across the United States and can be found in hardiness zones 5 through 8, and parts of Eastern Canada.
The Tree of Heaven can be found in abundance around the Mediterranean area of Europe but has been limited in spreading to northern parts of Europe because of cold weather. The Tree of Heaven can also be found in the north and southern parts of Africa, southern South America, and Australia, although it is not widespread in any of those areas just yet. Further, in its native range, the Tree of Heaven grows in Northeast China, Central China, and Taiwan.
Apart from just it’s location on the globe, the Tree of Heaven does not grow well in shade, and it usually grows after a site disturbance. After an environmental disturbance, like a forest fire or windstorm, sunlight is more able to reach a forest floor, and once the sunlight gets to any seeds of a Tree of Heaven – these trees will quickly outgrow anything else.
Why Is The Tree Of Heaven A Problem?
As beautiful as it is, the Tree of Heaven creates a lot of problems for surrounding vegetation around it!
The Tree Of Heaven Produces Invasive Root Suckers That Take Over Surrounding Vegetation
According to Pennsylvania State University, not only can the Tree of Heaven produce 300,000 wind dispersed seeds per year, it can also spread by root suckers. Root suckers are growths that arise from the roots, up to 50 feet from the parent Tree of Heaven, and those little root suckers will turn into full grown clones of the parent tree. Tree of Heaven root suckers can start producing seeds in as little as 2 years, and a lot of problems quickly come from it.
The Tree of Heaven is a problem because the abundance of seeds and root suckers it produces allows it to completely take over a site. Since the Tree of Heaven can grow 10 to 15 feet per year, they quickly outcompete the native vegetation in the area. The Tree of Heaven produces an allelochemical called Ailanthone, into the surrounding soil which prevents other plants from growing.
The Tree of Heaven isn’t the only invasive tree in the U.S. Read our article about invasive poplar trees and what to do if you have one in your yard.
The Tree Of Heaven Has An Unpleasant Odor
Another problem that arises with the Tree of Heaven is that it produces an unpleasant odor – from its flowers, and also from any part of the tree that is damaged.
Since the Tree of Heaven has little wildlife value, with most grazers finding it unpalatable, it causes major ecosystem disruptions by displacing not only other plants, but the wildlife that’s in the area that it takes over.
Why Is It Called The Tree Of Heaven?
You may be wondering: why does an invasive tree that smells bad be referred to as the Tree of Heaven? Well, when the common name Tree of Heaven was given to the tree, it was due to its rapid growth rate towards the sky or Heaven.
Even the scientific name for the Tree of Heaven refers to its rapid growth rate. The genus name, Ailanthus, means ‘sky-tree’, and the specific epithet, Altissima, means ‘tallest’.
However, it is also believed that the name Tree of Heaven was created as a marketing strategy to get homeowners to plant the Tree of Heaven.
For more info on where the title “tree” comes from – check out our article Why Trees Are Called Trees, it’s so interesting!
Trees That Look Like The Tree Of Heaven
There are many native and non-native trees in North America that resemble the Tree of Heaven.
Below we will discuss the features of each species or genus which looks like the Tree of Heaven and how they can be distinguished from one another. We will focus on the easiest characteristics that can be used to identify these similar looking trees from the Tree of Heaven.
1. Walnut Trees (Juglans spp.) Vs. Tree Of Heaven
The walnut tree looks like the Tree of Heaven, but there are a few differences between the two!
Both Trees Have Compound Leafs
Walnut trees are often confused with Tree of Heaven due to them both having pinnately compound leaves. A pinnately compound leaf is made up of a central elongated petiole called the rachis which has a row of leaflets on either side. Pinnately compound leaves may or may not have a leaflet at the tip.
Walnut tree leaves differ from a Tree of Heaven by having serrated or toothed margins along the edges of each leaflet. The leaflets on the tree of heaven leaves have smooth margins except for one rounded tooth, called a glandular tooth, at the base of each leaflet.
They Produce Different Fruits
Another major difference between walnut trees and Tree of Heaven is the type of fruit or seeds they produce. Walnut trees produce a nut that is covered by a shell and a husk (picture a walnut that is in the genus Juglans). Tree of heaven produces samara, which is a dry indehiscent seed with an elongated papery wing allowing it to be dispersed by wind.
Two of the main walnut trees which are confused with the Tree of Heaven are the black walnut tree (Juglans Nigra) and the butternut tree (Juglans cinerea). The chart below lists walnut species in North America that can look like the Tree of Heaven.
| Common Name | Scientific Name | Range in North America |
| Japanese walnut | Juglans ailantifolia | Northeast |
| Black walnut | Juglans nigra | East, South, Midwest |
| Butternut | Juglans cinerea | East |
| Northern California walnut | Juglans hindsii | California |
| Southern California walnut | Juglans californica S. | California |
| Arizona walnut | Juglans major | Southwest |
| Little walnut | Juglans microcarpa | TX, OK, NM, KS |
| English walnut | Juglans regia | West, Northeast |
Want to learn more about walnut trees? Check out our article on the 5 best places to plant your walnut tree!
2. Ash Trees (Fraxinus Spp.) Vs. Tree Of Heaven
Ash trees can also be confused with the Tree of Heaven due to both having pinnately compound leaves.
Ash leaves can be distinguished from the Tree of Heaven by the growth of the leaves on the branch. Ash tree leaves grow in an opposite pattern with one leaf directly across from the other on a branch. A Tree of Heaven’s leaves has an alternate pattern with leaves that never grow directly across from one another on a branch.
There are many ash trees which can be confused with the Tree of Heaven due to the pinnately compound leaves including Green Ash (Fraxinus pennsylvanica) and White Ash (Fraxinus americana). Below is a list of ash trees found in North America which can look like the Tree of Heaven !
For more info on ash trees head over to our article on 5 Reasons Why Ash Trees Make Wonderful Shade Trees.
| Common Name | Scientific Name | Range in North America |
| Texas ash | Fraxinus albicans | TX, OK |
| White ash | Fraxinus americana | East |
| Singleleaf ash | Fraxinus anomala | Southwest |
| Mexican ash | Fraxinus berlandieriana | TX, LA, MS |
| Carolina ash | Fraxinus caroliniana | SE |
| Fragrant ash | Fraxinus cuspidata | TX, NM, AZ, NV |
| California ash | Fraxinus dipetala | West |
| European ash | Fraxinus excelsior | Northeast |
| Goodding’s ash | Fraxinus gooddingii | AZ |
| Gregg’s ash | Fraxinus greggii | TX, NM, AZ |
| Oregon ash | Fraxinus oregona | West coast |
| Black ash | Fraxinus nigra | Northeast |
| Chihuahuan ash | Fraxinus papillosa | TX, NM, AZ |
| Green ash | Fraxinus pennsylvanica | East, South, Midwest |
| Pumpkin ash | Fraxinus profunda | East |
| Blue ash | Fraxinus quadrangulata | East |
| Shamel ash | Fraxinus uhdei | CA |
| Velvet ash | Fraxinus velutina | Southwest |
3. Hickory trees (Carya Spp.) Vs. Tree Of Heaven
While hickory trees also have pinnately compound leaves like the Tree of Heaven, they typically have fewer than 11 leaflets per leaf which are fewer than the Tree of Heaven’s. The leaflets also have serrated margins while the Tree of Heaven’s leaflet is smooth with only a single tooth on each side of the base.
A hickory tree’s fruits are also much different from that of the Tree of Heaven. The fruits of hickory are nuts which are encased in a hard shell and husk (think pecans which are also in the genus Carya).
Below is a list of other hickory trees found in North America that can look like tree of heaven.
| Common Name | Scientific Name | Range in North America |
| Water hickory | Carya aquatica | Southeast |
| Butternut hickory | Carya cordiformis | East, South |
| Scrub hickory | Carya floridana | Fl |
| Pignut hickory | Carya glabra | East, South |
| Pecan | Carya illinoinensis | East, South |
| Shellbark hickory | Carya laciniosa | East, South |
| Nutmeg hickory | Carya myristiciformis | South |
| Red hickory | Carya ovalis | East |
| Shagbark hickory | Carya ovata | East, South, Midwest |
| Sand hickory | Carya pallida | Southeast |
| Black hickory | Carya texana | Southeast, South |
| Mockernut hickory | Carya tomentosa | East, South |
4. Sumac Shrubs (Rhus Spp.) Vs. Tree Of Heaven
Sumac shrubs are usually only confused with the Tree of Heaven when the Tree of Heaven is young, as it can be confused with other shrubs – however, there are some great ways to identify and tell them apart!
You Can Identify Them By Their Leaves
Both sumac and the Tree of Heaven have pinnately compound leaves. However, some sumacs such as Staghorn Sumac (Rhus Typhina) have serrated margins on the leaflets which distinguish it from the Tree of Heaven. The leaf petioles and stems of Staghorn Sumac are also covered with fine hairs which the Tree of Heaven does not have.
Winged Sumac (Rhus Copallinum) leaflets are also smooth like the Tree of Heaven, but they have growths on the leaf rachis resembling wings which can help you distinguish winged sumac from the Tree of Heaven.
You Can Identify Them By Their Fruits
Sumacs can also be differentiated from the Tree of Heaven by their fruits. Sumacs produce drupes which are fleshy fruits with a hard seed in the center. Sumac drupes form large, tightly packed clusters which resemble a cone and are typically red in color when ripe.
The drupes of sumac are easily differentiated from the papery samaras of the Tree of Heaven.
5. Kentucky Coffee Tree (Gymnocladus Dioicus) Vs. Tree Of Heaven
The bark of the Kentucky Coffee Tree is rough and scaly and will easily distinguish it from the much smoother cantaloupe-like bark of the Tree of Heaven, especially in mature trees.
The fruit of the Kentucky Coffee Tree forms in pods, with 3 to 5 seeds per pod. These are easily differentiated from the samaras produced by the Tree of Heaven.
6. Yellowwood (Cladrastis Lutea) Vs. Tree Of Heaven
Mature Yellowwood can be distinguished from the Tree of Heaven simply by the smooth bark it has versus the Tree of Heaven’s bark which has more of a cantaloupe texture to it.
Yellowwood leaves are pinnately compound but typically have no more than 5 to 9 leaflets while the Tree of Heaven’s leaves rarely have fewer than 11 leaflets.
The fruit of the yellowwood is also a key characteristic since it produces long brown pods in clusters with 6 seeds per pod similar to the Kentucky coffee tree, which are much different than the samaras of tree of heaven.
7. Amur Cork Tree (Phellodendron Amurense) Vs. Tree Of Heaven
Amur cork trees are another non-native species in North America that resemble the Tree of Heaven. While it has pinnately compound leaves, the leaves are opposite to one another on the stem like ash trees.
Amur Cork Trees also have corky bark which is easily distinguished from the much smoother cantaloupe-like pattern on the bark of the Tree of Heaven.
Amur Cork Trees can also be distinguished from the Tree of Heaven by their fruits which are berries while the Tree of Heaven has samaras.
The Tree Of Heaven Has An Unpleasant Odor That Can Help Identify It
There are many identifying characteristics of the Tree of Heaven which can be used to distinguish it from other plants. One characteristic that is present year round is from the odor which has been commonly described as rotten peanuts or dirty gym socks. The flowers will emit this odor in late May through July when they are present, but it is also produced when you crush the stems or any part of the tree.
Since the sap can cause an allergic reaction in rare cases, you should not crush the stems or any part of the plant to smell them. Use the other diagnostic characters provided above to identify tree of heaven.
How To Get Rid Of The Tree Of Heaven
There are many strategies that can be used to get rid of the Tree of Heaven if you find it on your property. All of the strategies require that you monitor the area for several years after treatment in order to ensure that no further growth occurs from root suckers or seeds which remain in the soil. You will also likely need to use multiple methods together to get full control if you already have an established tree.
Remember – any time you are removing a tree or using chemicals to control a pest, there can be significant risks involved. That’s why we recommend you use a professional to avoid creating an unsafe situation. Find a local ISA-certified arborist to ensure the job is done right.
Mechanical Control
Mechanical control is a way you can get rid of the Tree of Heaven. Mechanical control is the use of barriers such as fences and the removal of a pest by mechanical means such as mowing.
Mowing is a great mechanical control method for root suckers – which will pop up from the roots of an adult tree, even after the tree is removed.
If you continue to cut back newly emerging root suckers from the roots without allowing them to get too big, you can deplete the carbohydrate reserves in the roots and ultimately eliminate the Tree of Heaven completely.
Chemical Control
Chemical control is the use of pesticides to control a pest. Chemical control is perhaps the most effective way to control mature Trees of Heaven. However, combining chemical control with the mechanical control of mowing is the most effective way to control the newly emerging Tree of Heaven on your property.
Remember, since the Tree of Heaven can grow new trees from its roots, if you cut down the tree, you will likely find more trees continuing to try and sprout up from the stump and remaining roots. You can eliminate these root suckers and stump sprouts using chemical control.
If you have a large Tree of Heaven, it is best to have a professional cut the tree down for for safety purposes. Once the main trees are removed, spray the stumps and any new trees that emerge with glyphosate or triclopyr. Here are two of our favorite products to do so.
We like Round Up Pro Concentrate since it contains the higher concentration of glyphosate recommended by the Forest Service or this ITS Supply Triclopyr 4 which is a generic brand and more cost effective.
Cultural Control
Cultural control refers to actions you can take to make the environment less suitable for the pest you are trying to control. The most effective way to culturally control the Tree of Heaven is to know how to identify it and remove it, by pulling it up as soon as you see it begin to grow.
Make sure to wear protective gloves when pulling up the Tree of Heaven since the plant can cause allergic reactions in some people. We like these Cool Job Gardening Gloves for women, since they come in smaller sizes and have a rubber coating to prevent any contact with tree of heaven sap. These men’s Cool Job Gardening Gloves also have the rubber coating and are available in larger sizes.
You should also make sure that if you have been in an area where the Tree of Heaven is growing, you don’t take any seeds back to your property with you, since the seeds can spread by getting stuck to your car tires to the hair on your pets!
Biological Control
Biological control is the use of an introduced natural enemy or predator to eliminate an unwanted pest. While there currently isn’t an approved biological control agent for the Tree of Heaven in North America, there is ongoing research that is focused on certain insects which may be able to reduce the spread of these trees.
According to the USDA, researchers are hopeful to have a biological control method available for the Tree of Heaven in the near future.
That’s A Wrap!
The Tree of Heaven has become an invasive tree species on every continent, except Antarctica, since its movement out of its native range in China and Taiwan. It can easily outcompete native plants and has little wildlife value allowing it to cause significant damage to ecosystems.
There are many trees that look like the Tree of Heaven at various stages of growth. Often the leaves are most easily confused, but with the use of this guide, you should be able to easily distinguish other trees from the Tree of Heaven by using the leaves, bark, stems, and fruits.
There are many different ways to get rid of the Tree of Heaven if you find it on your property. The most effective management strategies tend to use several of these methods together to get complete control of the Tree of Heaven.
Remember, the earlier you identify and remove the Tree of Heaven from your property, the easier it is to remove it.
References
Ding, J., Wu, Y., Zheng, H., Fu, W., Reardon, R. and Liu, M., 2006. Assessing potential biological control of the invasive plant, tree-of-heaven, Ailanthus altissima. Biocontrol science and technology, 16(6), pp.547-566.
Enescu, C.M., Houston Durrant, T. and Caudullo, G., 2016. Ailanthus altissima in Europe: distribution, habitat, usage and threats. European Atlas of Forest Tree Species. Publications Office of the European Union, Luxembourg, pp. e01ca33.
Heisey, R.M., 1990. Evidence for allelopathy by tree-of-heaven (Ailanthus altissima). Journal of Chemical Ecology, 16(6), pp.2039-2055.
Sladonja, B., Sušek, M. and Guillermic, J., 2015. Review on invasive tree of heaven (Ailanthus altissima (Mill.) Swingle) conflicting values: assessment of its ecosystem services and potential biological threat. Environmental management, 56(4), pp.1009-1034.
