Weeds have a difficult time germinating and becoming established in a thick, healthy lawn. The path to health for any lawn includes routine fertilization. Zoysiagrass lawns require less nitrogen than other warm-season grasses and no fertilizer at all during the winter. Use a broadcast or rotary spreader to fertilize zoysiagrass, and fertilize it early in the day.
Apply the first feeding three weeks after the zoysiagrass turns green. You will need 3 pounds of 16-4-8 fertilizer for every 1,000 square feet of lawn. Repeat this application in late June and again in mid-August. In mid-September and October, switch to a 6-6-12 formula at a rate of 8.3 pounds per 1,000 square feet.
Add the fertilizer to the spreader's bin.
Begin walking at a brisk pace across the lawn and turn on the spreader. Turn off the spreader when making turns. This will ensure you don't over-fertilize in spots.
Walk in strips, each strip just slightly overlapping the wheel marks made on the prior strip.
Water the lawn after fertilizing. Provide 2 inches of water so the fertilizer gets down to the roots.