Three Invasive Species and How to Manage Them
Creating better wildlife habitat is hard work, so there are few things as frustrating as finding invasive species popping up in a pollinator plot or in a drainage. Learning how to identify common invasive plants before they become difficult to manage is key in making sure quality habitat stays quality.
Bush Honeysuckle
Bush Honeysuckle is infamous, not just for its frustrating resiliency, but also for how common it is and how devastating it can be to wildlife habitat in the long term. Introduced as an ornamental plant, erosion control and as a food source for wildlife, bush honeysuckle quickly spread throughout the US. In addition to failing to control erosion or providing sufficient food for wildlife, bush honeysuckle forms dense thickets that choke out native plants. They are especially prolific in draws, alongside streambanks and will quickly consume old fields and forests alike. It is frequently spread through bird droppings, which makes controlling this frustrating species an important part of a long term management strategy.
Mature plants can be efficiently killed using foliar sprays or hack and squirt methods. Foliar sprays are best done after native plants have gone dormant in the fall and while bush honeysuckle is still green. Simply put, foliar spraying is spraying the foliage of bush honeysuckle with a herbicide which will kill the entire root system of the plant as well as the leaves. Glyphosate is the most common herbicide used in this application. Hack and squirt involves cutting down or topping the honeysuckle bushes and immediately treating the stump with glyphosate or triclopyr. It is important to note that bush honeysuckle must be immediately treated when its cut for the treatment to be effective.
Once the large plants are removed, smaller plants can be controlled by a combination of pulling them up by hand, spot spraying and prescribed fire. While prescribed burns will kill the tops of larger plants, it won’t kill their root system and the plant will resprout.
Sericea lespedeza
Sericea lespedeza is a warm season, perennial legume that outcompetes other native forbs and holds little value for wildlife. With seeds that remain viable for twenty years, it spreads quickly and is difficult to control. Its invasive nature has led a number of states to ban its sale and every year wildlife professionals and landowners spend a significant amount of time keeping this plant out of grasslands.
Sericea lespedeza can be controlled through a combination of herbicide application, mowing and prescribed fire. Cody Stegman, Quail Forever Habitat Specialist in Kansas suggests using prescribed fire in the late summer when Sericea begins to flower. John Holmes, Clinton Wildlife Area Habitat Specialist, stressed the need for a consistent, long term approach to managing sericea, which included herbicide use. Spraying both adults plants and emerging plants, with additional disturbance such as prescribed fire can help get on top of sericea issues. Keeping this invasive plant out of pastures and grasslands requires annual upkeep, but it is possible to keep sericea at bay.
Callery Pear
Woody encroachment is one of the primary threats to intact grassland ecosystems in the United States. Nearly 8 million acres of intact grassland habitat in the US is threatened by woody encroachment, according to the Nebraska Great Plains Grassland Initiative of the federal Natural Resources Conservation Service. In fact, according to the National Wildlife Federation, grasslands are now disappearing at the same rate as rainforests. The Callery Pear is an invasive species with serious negative implications for the spread of woody encroachment.
“It's one we worry about because it poses the threat of woody encroachment at a much faster rate than our other native trees and shrubs that try to move in on grasslands,” says Valarie Kurre, “This species is also problematic because, in many states, it can still be bought as an ornamental species for homeowners and municipalities. However, there are several states that now have bans on them being sold, including Missouri.”
For removing and managing Callery Pear, Kurre recommends a combination of burning to expose small trees and herbicide treatments when combatting this invasive tree. Small stems can sometimes be pulled out of the ground from moist soil. They can also be treated by foliar spraying using a systematic herbicide. For larger trees, multiple herbicide methods can be used, including basal barking (for trees up to six inches in diameter), girdling, and cut stump. Basal barking involves spraying the base and exposed roots young Callery pears with a combination of herbicide and basal bark oil when their outer layer of bark isn’t thick enough to protect the plant against the chemical. Cut stump removal involves cutting down the tree and then treating the stump with herbicide.
Cut stump and basal barking are best performed during late winter/early spring or in summer. Prescribed burns will kill the seeds but will only top-kill trees, causing many suckers to sprout from the roots.
Team Work
Landowners will find more success in the fight against invasive species if they can get assistance from other landowners and conservation professionals. Joining a Prescribed Burn Association can help landowners get prescribed fire on the ground. Prescribed Burn Associations are collectives of like minded landowners, who pool resources, manpower and equipment to do burns on PBA member’s land. The Great Plains Fire Science Exchange map can help landowners find Prescribed Burn Associations in their area.
County soil and water districts, as well as local Quail Forever chapters may have equipment such as ATV sprayers for herbicide applications. Landowners can learn more about how they can effectively combat invasive species by contacting a Quail Forever biologist. Getting ahead of invasive species can be difficult, but with help and a little knowledge, landowners can make big improvements for wildlife on their properties.