Invasive Plants: What’s the Big Deal?
The types of soil, weather conditions, plants and animals found in an area are all linked together. They have evolved over time to support one another and provide the things necessary for a balanced existence. When something changes, it has a ripple effect on all of these components. Some of the effects may be minor, some may not.
Non-native plants are those that occur outside of their native ranges, typically as a result of human actions. The new environment may provide perfect soil and weather conditions, but their natural controls – animals that eat them or diseases that would keep their numbers in check – might not be a part of the new habitat. If there are no checks and balances, these conditions set up a situation where the invasive plant can thrive, produce lots of seeds and out-compete native plants for resources such as nutrients, space, sunlight. Non-native plants do not benefit their new habitat in the same way; they do not produce food for the animals that live there, their root systems may not perform proper functions, such as holding the soil in place to avoid erosion. Plant diversity decreases and can no longer support the variety of animals that called that habitat home.
We challenge you to see if you can find invasive plants living right here in Hamilton County. Below, we’ve identified six invasive species that you can see signs of this spring. Ohio has many different types of invasive plants, but these are ones most obvious in spring and are certainly on the top of the list.
Lesser Celandine (Ficaria verna)
Described by local experts as a ‘sneaky’ and ‘stubborn’ plant, lesser celandine begins to grow in late January. As spring progresses, it forms dense carpets of dark green leaves with bright yellow flowers. By summer, the plant seems to disappear from view. This member of the buttercup family looks very similar to the native Marsh marigold and in fact will grow in some of the same places. Lesser celandine is mostly commonly found in wet environments, but also along hillsides and in the woods. It is native to Europe, Northern Africa and Asia. It most likely was brought to North America as an ornamental.
Callery Pear (Pyrus calleryana)
Callery pears (also known as Bradford pears) became cultivated in the early 1900s as an attempt to save commercial pears from a blight that was affecting them. Native shoots were grafted onto the Callery pear rootstock and resulted in cultivated varieties with devastating results. The cultivated varieties can cross breed easily, resulting in trees that carry the genes of the Callery pear. These include weak wood that splits easily, prolific blooms that have an unpleasant odor, obnoxious fruits that also have a bad smell and little nutritional value, so birds and other animals need to eat much more of them (which then also spreads the seeds) and 4-inch thorns that can puncture tractor tires! Despite these issues, these pear trees were made available to the public in the 1960s and became very popular for their prolific blossoms and red leaf color in the fall.
Bush Honeysuckle (Lonicera tatarica)
Bush honeysuckle came to North America in the late 1800s from various places in Asia and eastern Russia as an ornamental plant, for erosion control and for wildlife forage/cover. This upright shrub can grow from six to 15 feet tall and can be confused with native honeysuckle, Making proper identification important. Branches of the native varieties have solid stems, whereas the non-natives have hollow piths. The leaves come out usually about two weeks before the leaves of other shrubs and trees and remain on the shrub long after all leaves have fallen off other plants. The flowers are tubular in shape and bloom from early to late spring and result in bright red berries. Their root system is extensive and shallow, allowing them to out compete other plants for soil, sun and nutrients.
Japanese Honeysuckle (Lonicera japonica)
Japanese honeysuckle, a close relative of bush honeysuckle, is a vine that is considered semi-evergreen with leaves that stay on well into late winter. The stems are hairy and can be more than 30 feet long! The tubular flowers are white to pink and turn yellow with age. They are in bloom from April to June. It is fast growing, and can cover large areas of ground as well as tree tops, limiting the available sunlight for native plants, and causing the trees to carry quite a bit of extra weight. This leaves them vulnerable to windstorms and makes it easier for them to get blown over.
Winter Creeper (Euonymus fortunei)
Winter creeper (or wintercreeper) is native to China and East Asia. It was brought to North America as an ornamental ground cover. It stays green all year and creeps very fast, quickly over taking everything in its path. It grows in dense mats that smothers out other plants, including trees. Winter creeper grows well in full sun and in shade, enabling it to spread through our forests quite easily.
Garlic Mustard (Alliaria petiolata)
Garlic mustard can grow in a variety of places, forests, fields, fencerows and roadsides. It is a biennial herb that has a garlic-like odor when the leaves are crushed. It was introduced from Europe for herbal and medicinal purposes. It was first reported growing wild in the United States in 1868.
These invasive plants have several characteristics in common. They are fast growing, have strong root systems, can grow in several different types of habitats, can grow in sun or shade and it takes persistence to get rid of them. Hand removal is best for small infestations, but you must take care to remove the entire plant – remove all of the roots and bag them up and take them away. It takes repeated clearing attempts to rid invasive plants because any bit of the root system left in the ground is enough to regrow. Larger infestations often require the use of chemicals and that is best done by consulting a professional to ensure that chemical application is done correctly and safely for you and the environment.
Director of Education & Events