FORT WAYNE, Ind. (WANE) – As you are doing your spring planting this year, you should make sure you know what plants are actively invasive in our area. Turns out there are more than you might realize.

Jayde Grisham, Educator in Urban Agriculture and Horticulture at the Allen County Purdue Extension office, knows all about invasive plants. Before we talk about which plants are currently most invasive, let’s focus on how a plant becomes invasive and what can be done about them.


In the past, there was not a lot of research done on invasive plants. They were bought and sold and used for a variety of purposes. They were once considered beneficial in some capacity. They could have been used for erosion control, landscaping, and pest management.

Over time though, these plants do so well that they outcompete and take over native plants. This can happen in several decades, a couple decades, or even within a year; it depends on how many are initially planted and how quickly the plants can reproduce. Plants that can produce an abundance of seeds are particularly hazardous. This is why it is important to identify and spread awareness about these plants.

Invasive plants have no natural predators and they eradicate over time the native plants that local flora and fauna rely on as part of their life cycle. This ultimately decimates biodiversity, which is important to help buffer any sudden changes in temperature or weather; there needs to be a variety of plants and organisms living in an area to protect against habitat loss. Insects and birds that rely on native plants suffer the consequences of an invasive plant overtaking a native plant that is a part of the ecosystem as well. An invasive plant can destroy crops, impact the environment, take over forests, and impact fisheries.

An invasive plant will not impact your day to day life, but there are negative impacts to the economy, parks, and wild spaces in our area. Local parks have to spend time, money, and resources to remove invasive plants. This takes away the opportunity to use those resources for other projects to benefit the public. It is estimated that at least 20 billion dollars is spent annually in the United States to control invasive plants.

Eventually, something will adapt to be able to eat an invasive plant. However, expensive and negative consequences will have likely already occurred by this point. It is also difficult for the problem of an invasive plant to resolve itself when more invasive plants end up being introduced. Plus, there are invasive insects and birds that may rely on a plant that is also invasive. It is a constant effort to keep all invasive things at a low level, while watching out for new invasive things.

Top Invasive Plants in Northeast Indiana and Northwest Ohio

#1: Asian Bush Honeysuckle

This is an illegal invasive plant that is the most widespread in our area. There are four varieties in Indiana and all are prohibited from being planted. The plant was intentionally planted for soil erosion, but then it took over and rapidly spread throughout many of our area forests and parks. It is typically between 5 and 16 feet tall. The plant puts out leaves early in the spring and holds them really late in the fall. It grows red berries where the leaves meet the stem. The stem itself is also hollow. To treat it, a stem can be cut, but it will grow off more side shoots unless continually treated.

#2: Callery Pear

This tree is still legal to plant and many of these trees are in our area. They were popular for landscaping purposes after around the 1950s. They were initially expected to not produce an ample amount of seeds. However, the plant can send up root suckers (vegetative growths that stem from the tree’s root system), which can in time produce more trees. It can also cross pollinate with other similar species in the environment. Seeds produced by the tree can be eaten by birds and dispersed by their bird poop. This is why these trees pop up in fields or along roadways.

The tree grows to about 30 to 50 feet tall. The ‘Bradford’ Pear is a variety of Callery. Young trees may be thorny and they have glossy leaves that appear in clusters and have slightly folded edges. The trees are hardy and are a food source. The springtime bad smell of the tree’s flowers has to do with the insects it attracts. The tree produces clusters of blueberry-sized brown fruits later in the year.

#3: Burning Bush

This plant is still legal to plant and is currently not prohibited in Indiana yet. Many are still in stock in nurseries and they are sold to customers for business. This plant has been used as a simple landscaping bush, but have become invasive based on how quickly they grow. The plant produces many seeds that can be carried off by birds and it produces little plants off of the main plant. This causes renewed growth even after it is cut down. People tend to plant a burning bush close to their house and do not realize they can become very large. They typically grow up to 5 to 10 feet tall, but some can get up to 20 feet or higher and 15 feet wide or greater. Imagine many plants of this size across acres and acres of forested areas. It is very difficult to kill completely and be replaced by native plants. It also has no natural pests in our area.

They have corky protrusions that look like wings on the end of the leaves. They are best known for their fall color. The plant’s flowers are small pale green and the plant’s fruit is pinkish purple and orange.

#4: Poison Hemlock

This is a poisonous plant that is herbaceous, meaning it does not have a stem that forms a trunk. It lives for two years. It looks like a plate when it grows the first year, then grows up to 5 to 8 feet tall the second year. It has a smooth stem with purple splotches, which is how you can identify it as a poisonous plant. It often comes in clusters and has a dark spot in the center.

It was originally used as medicine, but has since spread because it is used for decorative purposes. Consuming small amounts are very dangerous for livestock; a lot of these plants grow and spread in areas that have livestock. Consumption of 50 grams or so by large livestock can result in death within a couple of hours. Juices from the plant that come into contact with your eyes or mucus membranes can cause an allergic reaction. It is safe to touch, but you should wear gloves to make sure you don’t rub plant sap on yourself.

#5: Autumn Olive

This plant is illegal. It was first used to help control soil erosion. It is very similar to the Asian Bush Honeysuckle, as it has become more widespread and grows red berries. It can grow up to 20 feet tall. It has an alternating silvery underside foliage, with ruffled edges. It produces white small, narrow flowers. It is easy to spot from a distance, as it resembles a willow.

Autumn Olive

Honorable Mention: Japanese Barberry

This plant is illegal. It is a common landscape plant. It has spread throughout forested areas and does well in the shade or full sunshine. It has dark red foliage; tiny, oval-shaped leaves that are clumped tightly together; massive thorns, and is yellow on the inside of the plant’s stems. It also spreads seeds easily. This plant makes it difficult to navigate through a forest because of all the thorns and thick branching. It also houses a lot of ticks, which can be dangerous.

Ways to Help

You can help alleviate the problems brought about by invasive plants by making sure you are aware of if a plant is invasive before buying it. Not all invasive plants are prohibited from being bought or sold. You can find a full list of invasive plants here.

If you have an invasive plant currently in your yard, consider removing it or replacing it with a native plant. A lot of times an invasive plant requires a special treatment or herbicides though because an invasive plant is hardy. Consider consulting with an expert to make sure they are removed properly. Sometimes a plant removal can take years.

If you do not have a yard on your property, you can volunteer to plant native plants and remove invasive ones. You can also spread awareness by educating others on which plants are invasive and their consequences.

For more information, you can visit the Indiana Native Plant society. Click here to visit their website and click here to visit their Facebook group.