How to Overseed St. Augustine with K-31 Tall Fescue

Rake your lawn to remove twigs and other debris in preparation for mowing it.

Cut your St. Augustinegrass to a height of 3 inches. Rake the lawn again to remove the grass clippings.

Examine your St. Augustinegrass for thatch, a mass of intermingled dead and living plant parts that sometimes accumulates in lawns, harboring pests and preventing water and air from reaching the grass roots. According to the University of Florida, St. Augustinegrass has a history of excessive thatch buildup. Rent a power rake or a vertical lawn mower to cut the layers of thatch. Rake them off the lawn.

Pour 3 ½ pounds of K-31 seeds into a broadcast spreader and sow them from east to west. Fill the spreader with the other half of seeds. Broadcast them from southeast to northwest, as the perpendicular angle reduces bare spots.

Brush the grass with a patio broom gently to move the seeds from the tops of the grass blades down to the soil surface for germination.

Irrigate your lawn for 10 to 20 minutes after your sow the K-31 seeds. Continue to irrigate the grass for about 10 minutes twice a day for one week. One week after overseeding St. Augustinegrass, begin to apply ¼ inch of water a day. Two weeks later, change your irrigation schedule again to 1 inch of water when the K-31 blades begin to wilt.

Mow tall fescue back to 2 inches when it reaches 2 ½ to 3 inches. Keep the grass at 2 inches from fall through late winter.

Fertilize tall fescue after you mow it for the second time in the fall. Apply 1 pound of nitrogen per 1,000 square feet and water the nutrient in. Feed the winter grass again two months later in the same manner. Don't fertilize a third time to discourage continuing growth into spring when your permanent lawn starts to wake from dormancy.

Water K-31 infrequently starting in late winter to begin to weaken it, creating space for your permanent lawn to take over the area in spring.

Mow your winter lawn frequently and as close as possible in late winter so it loses vigor and begins to die, making room for your permanent lawn to become dominant again in spring.

Begin to follow the recommended maintenance schedule for St. Augustine grass as soon as it shows signs it's developing again.