A common request in the spring is how to get rid of crawfish that are making unsightly mud chimneys in lawns. Crawfish can be common in lawns and other low-lying areas where the water table in close to the surface. A single crawfish can dig a burrow that can extend several feet deep, and there may be dozens near a low spot in a lawn or near ponds and creeks.
Fortunately, crawfish and the chimneys they create, do not hurt plants or turf. They don’t feed on plants or roots and are considered detritus feeders; some are carnivorous. But spring is when they are spawning and cleaning out and enlarging their burrows. The burrows with their chimneys are, however, unsightly and cause increased wear on mowing equipment.
A practical way to deal with the chimneys is to rake them out or wash them away before mowing, but this can be time consuming. Here are some other strategies that may or may not work:
Try to lower the water table or direct drainage away from the area to promote drier soil conditions. This can make the area much less favorable for crawfish; however, this can be expensive and may not be effective during periods of regular heavy rains.
Pesticides and other chemicals are not recommended. As crawfish are associated with high water tables, there is an elevated risk that anything put into the burrow may contaminate the water table. There are no pesticides labeled for crawfish control by the EPA or for use in Kentucky. There are no chemical treatments of any type that can be discussed or recommended.
Trapping of crawfish can reduce their numbers in an area. There are commercial crawfish traps and some designs can be used for trapping on lawns. Generally, these are baited with pet foods or putrefied meat and need to be checked regularly and bait replaced as needed. Keep in mind that these baits will also attract raccoons, opossums, and other wildlife, as well as cats, so they need to be anchored to the ground with lawn staples or stakes.
While there is no silver bullet to control crawfish in lawns, the problem is usually seasonal. When the drier months of the summer arrive, the problems should diminish.