How do I control common lespedeza in my lawn?
Common lespedeza is a summer annual legume that can be a challenge to control in lawns. As common lespedeza matures, the stem hardens and become woody. This allows this weed to persist into the late summer. Flowers can be pink to purple. Below are examples of common lespedeza courtesy of Dr. Patrick McCullough, UGA Turf Weed Specialist.
So, how do I get rid of this weed? There are a few things that can be done to control common lespedeza in lawns. If you have irrigation, proper irrigation scheduling is essential for promoting a deep-rooted lawn. Overwatering can encourage the growth of this weed in shady areas. Soil compaction can cause lawns to thin, which can allow weeds to establish. Core aeration can aid in the management of soil compaction. Warm-season grasses should only be aerated when they are actively growing.
Proper mowing height is another cultural practice that can help with lawn health. Scalping thins out turf and helps with weed establishment. Below are mowing requirements for Lawns in Georgia.
Preemergent herbicides should be applied in the spring when soil temperatures reach the low to mid 50’s in the upper 4 inches of the soil profile. Pre emerge options include atrazine, dithiopyr and simazine. Post emerge options include metsulfuron, atrazine, and dicamba. Dicamba is often available in combination products that contain 2,4-D and other herbicides. Below is information on herbicide options and turfgrass tolerance to herbicides used common lespedeza control.
If you would like more information on Common Lespedeza in lawns it is available here.
My irises are dying!! Irises can get a soft rot that is caused by the bacterium – Erwinia carotovora. Erwinia produces a very foul smell which is a key characteristic of this disease. The leaves begin to turn brown and the plant will die back until it is dead. The disease is favored by wet, heavy soils or shady locations that tend to keep the ground continuously moist, which was common this past summer.
If the soft rot is severe, take up the rhizomes in late summer or early fall. Please try to destroy all rotted portions of the rhizomes. September is a great time to lift, divide, and transplant bulbs as Iris. Gardeners should plant in a new location or sterilize the soil. This disease can be worse if excessive moisture is available during the growing season. The disease is easily spread to new iris plantings by non-sanitized tools. To avoid spreading the soft rot bacterium, please dip tools in a bleach solution (1 part bleach in 10 parts water) before each new cut.
Gardeners should also be on the lookout for the iris borer. Iris soft rot can be associated with the wounds from iris borers. Control options for iris borers include imidacloprid. If you have any questions about bulbs, Erwinia or Iris borers contact your local county Extension agent.
Jeremy Kichler is the County Extension Coordinator and Agriculture and Natural Resources (ANR) agent for UGA Extension in in Colquitt County. He has been an ANR agent for 21 years. His phone number is 229-616-7455 and his email is firstname.lastname@example.org .