A 2019 survey of sericea lespedeza acres in Kansas estimated upwards of 75,000 acres of grassland in the Meadowlark Extension District with some level of the noxious weed present. Because of the plant’s ability to shade desirable forages (it can grow to three feet or more in height), a high water use requirement that steals from other forages, and allelopathic chemicals reducing forage germination rates (Oklahoma State research suggests up to 15 percent reductions in germination of tall fescue), sericea lespedeza has become a formidable foe in our grasslands.
There are various control options for sericea lespedeza (mowing, prescribed fire, grazing with different livestock species) but chemical control is the most common. Summer is a great time to initiate control efforts while sericea is in the vegetative stage and susceptible to herbicides like Remedy Ultra and PastureGard HL. Broadcast applications (one to two pints per acre Remedy Ultra or three fourths to one and a half pints per acre PastureGard HL) should be applied in spray volumes of 10-20 gallons/acre for best results. Surmount at two pints per acre is also an option. For spot application, mix a half ounce per gallon of PastureGard HL or a one percent solution of Remedy Ultra in water. Aerial applications should be done at a minimum spray volume of three (more is better) gallons per acre.
Repeat treatments will be necessary, even as initial treatments should reduce stands. Left untreated, sericea lespedeza takes over, earning it a prominent spot on the state’s noxious weed list, and requiring its control.
Whether just getting started or continuing a longer-term battle against sericea, there are lots of good resources available to assist. One of the most important is your local noxious weed director, a great resource for information on everything from product purchases to rates and timing. A second is your applicator. Good communication with them can enhance control efforts greatly. A third is the 2021 KSU Chemical Weed Control Guide, available from any District Office. One page of the book is devoted entirely to sericea lespedeza chemical control options. It can help you determine products to use now as the plants are vegetative as well as other options as the growing season progresses. Request a copy by contacting a District Office or e-mail me at email@example.com.
on Shade Trees
Two of our common landscape species – sycamore and maple – are prone to a fungal disease known as anthracnose, and this year has been perfect for it. Be on the lookout for it as the growing season continues.
Favored by cool, wet weather, young leaves may wither and turn black while older leaves may have brown areas along the veins. In severe cases, leaves may even drop, but don’t panic. Healthy trees will leaf out again in a few weeks with this defoliation doing little to affect the overall health of the tree. Fungicides don’t ‘cure’ affected leaves. The damage is done and chemical control is unnecessary.