Summer has just started, but let me warn you — fall and winter are coming. Time to prepare!
Sound ridiculous? Well, not really. Though it is hard to imagine cold weather amidst this heat, we need to start thinking about getting our lawns ready to survive this winter. We do this with proper care through the year.
When is the last time I can de-thatch or aerate my lawn? These practices stress the grass. The lawn will need time to recover before it can survive the winter. To be cautious, here on the coast we recommend that we aerate or de-thatch no later than the end of July. You can aerate or de-thatch now or put it off just a little while more, but try to remember to finish these practices soon.
Do I really need to aerate my lawn? As with many of my horticultural answers, I am going to say, “It depends!” We do not usually aerate as a general practice. We aerate when the soil is hard. Aeration helps break up compaction. This allows air and water into the soil, which ultimately helps roots to grow better.
To see if your lawn needs aerating, wet the soil deeply. Then use a wire or a small rod to push down into the soil. A wire flag works for this. If you cannot push the wire at least 4 inches or so into the ground, the soil may be compacted and need aerating. Try this in several areas, especially places where the grass grows poorly.
To aerate, use a core aerator that pulls cores out of the soil. The aerators with tines on them are not as good at relieving aeration deep in the soil. They work better for breaking up surface crusts. The aerators using blades to cut deeply into the soil work well, but they are hard to find.
Wet the soil deeply first and try to aerate as deeply as possible — usually about 3 inches deep. If you do not have a way to irrigate your lawn, just wait until we have had one of the long, hard rains we tend to get during the Hinesville Farmer’s Market on Thursdays.
Aerate until the ground has about 15 percent of the area covered with holes. This is difficult to estimate. Throw a ruler on the ground after you aerate. Estimate the amount of the edge of the ruler that touches a hole. Is this is less than 15 percent of the length of the ruler, continue to aerate until you reach 15 percent.
Do I need to de-thatch my lawn? Good lawn care should prevent thatch buildup. The exceptions to this would be Zoysia lawns, which seem to be more prone to thatch buildup, and new lawns that may not root in well and quickly become thatchy.
Thatch is a buildup of undecomposed stems and other materials. Rapid and excessive growth can lead to heavy thatch because plant material is produced more rapidly than it can decompose. Having said that, it is generally a result of improper care. Grass clippings from regular mowing do not contribute to thatch. However, once a thatch layer has developed, clippings further speed its formation. Some thatch is helpful. Do not try to control all thatch.
To see if you have a thatch problem, cut down through the thatch with a shovel. Do not be concerned until the thatch gets thicker than a half inch (or 1 inch for St. Augustine). If the lawn has a thatch layer thicker than this, you may need to reduce this layer. Too much thatch makes it hard for the plants to form good strong roots.
If you use a de-thatching machine (also called a verticutter), be careful to use it properly and do the necessary research for your turf type.
When can I seed or sod? The best time to seed and sod centipedegrass is May through July. It is not too late to seed now, but I would not delay much longer. The grass needs time to establish before facing the cold winter weather.
Spread the seed evenly using a mechanical spreader. Mix the seed with a carrier, such as sand, at the rate of one-fourth pound of seed per gallon of sand. Divide the mix into two equal parts and spread half in one direction and the other half at a right angle to the first direction. Then roll the area with a lightweight roller to ensure good seed/soil contact.
Apply a straw mulch over the newly seeded section to retain soil moisture for more rapid germination and reduced soil erosion. The seed must be kept moist, so daily, light irrigations are needed for the first three weeks. Germination should occur in two weeks if the seeds are kept moist.
When do I need to fertilize? A fertilization program should be based on soil test analyses. One to two pounds of nitrogen per 1,000 square feet per year is generally good for centipede, although it will grow well without any fertilizer. UGA Extension recommends that you apply nitrogen in split applications. Apply the first two to three weeks after spring green-up (May) and the second in midsummer (July). Around Independence Day is a good way to remember when to put out that final fertilizer application.
Apply the fertilizer evenly over the area when the grass leaves are dry. Use a mechanical spreader and use the two-direction application procedures as described for seeding.
Preparing for the winter now seems illogical, but not to the seasoned gardener. Planning now may save your lawn from death or decline during the winter. The things you do now can help you to have a better looking lawn next spring!