As the weather begins to warm up, the warm season turfgrasses, Bermuda, centipede, St. Augustine and zoysiagrasses, are beginning to come out of winter dormancy and turn green. When soil temperatures rise in the spring, turfgrass plants begin to generate new leaves and stems.
The period when the grasses come out of dormancy influences the health and quality of the lawn for the rest of the growing season. Warm season turfgrass begins to come out of dormancy when the temperatures remain above 60 degrees for several days. The process of the turf going from dormancy to turning green and actively growing takes several weeks. The amount of time varies for each type of grass and their varieties.
Sometimes lawn grasses are adversely affected by extremely cold temperatures. They may have been weakened or killed in some areas. Diseases, poor cultural methods or adverse weather conditions during the growing season in the previous year can make the turf more susceptible to winter kill.
Examine the lawn and the cultural practices that you are using to figure out what may be causing the problem. Rake out the dead areas and leave any living grass. The grass will fill in these areas, or you may have to reseed or sod. Excessive shade or poor drainage also will delay the green-up phase.
Homeowners can take several steps during the green up period to improve the ability of the lawn to thrive during the growing season. As it begins to start turning green, reduce the mowing height to renew the turf. Performing this task will allow the soil to warm up faster, improve the penetration of air, water and light, which will increase the rate at which turf grasses green up.
Be careful when lowering the mowing height of zoysiagrass because it is not as tolerant of cutting at a reduced height. Do not remove over one-third of the leaf blade, even when dormant, since this may be harmful to the zoysiagrass. Make sure the mower blade has been sharpened prior to mowing. Also, use extreme care when mowing on uneven surfaces to avoid causing damage to the grass.
Lawns growing on compacted soil will take longer to turn green because the conditions restrict root growth and limit the infiltration of air and water. Aerating the soil with a hollow tine aerator will help relieve soil compaction. Wait until after the lawn has completely turned green and is actively growing to aerate.
Consider having your soil tested. Use a small shovel or soil probe and take a 4- to 6- inch deep sample from 10 to 12 areas across your lawn. Mix the samples together in a bucket, put two cups of the soil in a Zip-loc bag, and bring to the Extension office. The sample will be sent to the soil testing lab at the University of Georgia to be tested for pH and several of the major nutrients. You will get the results back in seven to 14 days.
To prevent damage that may occur from any late spring freezes, do not apply any fertilizer until the lawn has completely come out of dormancy. Apply a complete fertilizer such as a 10-10-10, 16-4-8 or some other turfgrass fertilizer according to the soil test’s recommendations. Thoroughly water the lawn after the application.
Pre-emergent herbicides, the ones that control weeds as they emerge, cannot be applied during this transition period. Wait until after the turf has come out of dormancy before doing so. However, post-emergent herbicides, which control weeds after they have germinated, may be applied to weeds during the spring green-up phase since they do not injure or kill the grass.
Remember, actions taken during the period when the grass comes out of winter dormancy will influence how well the lawn does during the spring and summer months. With a little planning along with proper cultural practices, your warm season lawn can be healthy, attractive, and the envy of your neighborhood.
Timothy Daly can be reached at 678-377-4010 or firstname.lastname@example.org.