Q. Our lawn–For the most past, it is way too thick. Even the front, which was resodded not too long ago, is a jumble of roots. We thatch every year–had it professionally done last year–and of course fertilize and water. Will using an aerator help? Any suggestions will be appreciated as we are disappointed that it doesn’t show all the time and effort that is expended on it. Thank you much– Judy Payne – Puyallup, Wa
PS. Also a schedule for lawn maintenance would be helpful.
A. From your description and the fact that you are thatching each year I will assume that your thatch layer grows deeper than ½ inch. An ½ to ¾ inch layer of thatch is desirable as it protects the root system from foot traffic and keeps the roots cool in the summer. Any more than this then you develop the “thatch roof syndrome” where water and air do not penetrate the layer. Thatch is made primarily of stems and some surface roots. Contrary to popular belief the blades of grass do not contribute significantly to thatch development so mulch mowing (allowing the grass clippings to return to the turf rather than removing them in a mower bag) is not a causal factor. Using an aerator (core aeration is preferable) would be useful if the thatch layer is more than 2 inches thick. A longer-term solution is to determine which contributing factors are present in you lawn and correct them if possible. Bentgrasses (colonial) and Kentucky bluegrass tend to have a propensity to form thatch more than other grasses. The way you mow can also influence thatch development. If you regularly allow the grass to grow long between mowings or maintain the grass above the appropriate height for the type of grass you grow you can contribute to thatch development. This is because the grass stems can move up from the soil line where microorganisms can break them down. In a healthy thatch appropriate lawn there is a balance between thatch development and breakdown. So if you over fertilize the lawn with nitrogen you can throw the balance in favor of the thatch. In addition too little nitrogen (necessary for many decomposing organisms) can also slow down breakdown of the thatch. Low pH (optimal is 6.5 to 7) can also inhibit decomposition of thatch. Check your lawn for fertility and pH (soil tests) and adjust appropriately. Hopefully there are some practices you can change to treat the cause of the thatch buildup and reduce the amount of thatching your lawn will need which is treating the symptom. My website’s Garden Calendar Planner has a month-to-month tasks for the garden. The Landscape Tasks section may satisfy your need for a lawn maintenance schedule since it lists the major lawn tasks.