When Should I Fertilize Zoysia?

Growing Season

• In cool climates, like southern Missouri, homeowners fertilize zoysiagrass lawns from May until August. Early spring fertilization does little to improve grass but does, unfortunately, help weeds. Late fertilization interferes with grass' ability to adapt to winter conditions. In Florida, where temperatures are warm year-round, growers fertilize grass from February through November.

Frequency

• Homeowners apply the first fertilizer of the season approximately two weeks after spring grass takes on its green color. Four to six more applications are applied throughout the remainder of the growing season. Homeowners using liquid fertilizers make more frequent applications than those using granular fertilizers. University of Florida horticulturists recommend that lawns receive a total of 3 to 6 lbs. of nitrogen per 1,000 square feet throughout the growing season. University of Missouri horticulturists suggest 2 lbs. of nitrogen per 1,000 square feet of grass per growing season. The difference is due partially to Missouri's shorter growing season but other factors, such as soil type, are responsible for differing opinions.

Soil Tests

• Master gardeners overwhelmingly recommend that homeowners test their soil prior to fertilizing their lawns. A simple soil test saves homeowners, who may apply incorrect fertilizers in incorrect amounts, from causing lawn death. Soil tests measure the amount of nutrients in soil. Zoysia lawns require nitrogen, phosphorous and potassium to thrive. Fertilizer formulas list the amounts of nitrogen, phosphorous and potassium found in their mixes. If you learn your lawn is low in phosphorous, you can choose a mix with high phosphorous levels. A frequently recommended fertilizer formula for zoysiagrass is 16-4-8, meaning the mix is 16 percent nitrogen, 4 percent phosphorous and 8 percent potassium.

Considerations

• Before applying fertilizer to your zoysia lawn confirm that the lawn needs it. Zoysia is a dense-growing grass that turns brown when in need of water. Once watered, the grass greens up. Try watering before fertilizing as over fertilization leads to inconsistent top growth while increasing the risk of disease and root burn.