When to Cut a Lawn After the Seed Heads Emerge

Best Time to Seed

• The best time to seed a lawn is after soil temperatures reach at least 50 degrees Fahrenheit. However, avoid mid-summer planting when it will be difficult to keep the lawn moist because of the heat. Typically, the best time to plant grass seed is in mid spring, late summer or early fall, at least two months before freezing temperatures arrive.

Mowing Heights

• Know the recommended mowing height for your species of grass. For example, St. Augustinegrass should be mowed between 1 to 2 inches, perennial ryegrass between 1 1/2 to 2 1/2 inches, tall fescue between 2 1/2 and 3 1/2 inches and zoysia grass between 1/2 and 1 inch. Review the seed bag label for recommended mowing heights, or look online at a university extension website.

The First Mowing

• According to the University of California, for the first mowing you should wait until the grass grows at least 1 1/2 times the higher end of the recommended height range. Then, cut off only 1/3 of the total height. For example, for St. Augustinegrass, wait until the grass grows to 3 inches, then mow it with your mower set at 2 inches. For the first mowing, you can wait a bit longer to mow it so it has more time for the roots to become established. So, for the St. Augustinegrass, you could wait until it reaches 4 inches high and then mow off 1/3 of the height down to about 2 3/4 inches. Then, three or four days later, mow it down to 2 inches.

Maintenance Mowing Tips

• Mow frequently when the grass is dry and about 1 1/2 times higher than the recommended mowing height. Continue to cut off only 1/3 of the grass at a time. Routinely cutting grass too short only results in weak grass roots and may encourage weeds to grow. Every two or three mowings, switch mowing directions so you're not always pushing the grass in the same direction. During the summer, some grasses, such as Kentucky bluegrass, fare better if mowed a bit higher. Also, for the last one to two mowings in the fall, you can lower the mowing height to the lower end of the recommended height range to help prepare the grass for winter.