By now warm season lawns of Bermuda or zoysia grass should be green and actively growing. These types of turf grass are relatively easy to maintain if cared for properly. These following tips will help build a healthy lawn.
Both Bermuda and zoysia grass should be mowed at a height of 1.5 inches. Mowing should be done frequently so that no more than 30% of the grass blade is removed. This will help to prevent a buildup of clippings which create thatch. Cutting at a lower height reduces the overall health of the turf and does not help to lower maintenance.
When watering, irrigate for longer periods of time, allowing the water to filter deeply into the soil to encourage deep root penetration. If possible, water in the morning. This allows the grass blade to dry early in the day, reducing the chance of disease issues. By watering correctly a larger root system will grow, helping to sustain the grass during drought.
Herbicides may have been applied in March to control germinating weed seeds that come up in spring. This control, known as a pre-emergent, is effective for 6 to 12 weeks. By the first of June a second application should be put down to continue control of crabgrass and other germinating weeds. When using granular pre-emergent remember to water it in after applying it to the ground or it will not work on weeds. If a post-emergent control is used for spot treating weeds in the lawn then make sure that the lawn has been watered the day before applying control. This will aid in uptake of the chemical. Control is best when applied to young weeds on a calm day and when there is no rain within 24 hours after application.
There are few diseases that occur on Bermuda grass but those that might appear in a home lawn are caused by improper fertilization. Bermuda and zoysia grass should be fertilized after growth starts when the climate warms up. This year that growth will have started before it normally does. Each month apply .5 pounds of nitrogen per 1000 square feet to Bermuda or zoysia grass lawns during May, June, July and August to improve turf health. Do not fertilize past August if your lawn has one of these warm season grasses.
In zoysia, rust fungi will likely be an issue this year. Grass blades may appear yellow, orange or red in color and may release a cloud of spores when someone walks on the lawn. Shoes may appear red or orange after walking through the yard. Nitrogen fertilizer is the best way to combat this disease. By applying nitrogen as shown above the grass will remain healthy and fight against the rust fungi. In the fall, remove grass clippings after mowing. These clippings will contain black fungal spores of the rust disease which should not be allowed to overwinter on the lawn.
The Extension office is open Monday - Friday, located in Kennett, Missouri at 101 South Main Street (the old bank) on the 2nd floor. For horticulture questions contact the horticulture specialist at 573-686-8064. MU is an equal opportunity/ADA institution.