Managing Thatch In Your Lawn
Dethatching / Power Raking
De-thatching, or often called power raking, your lawn is the mechanical removal of excess thatch from your lawn. Unlike aerating, de-thatching is not a routine or annual service that your lawn requires. Most lawns have a consistently normal amount of thatch, between 1/2 and 3/4 inch, and with the help of certain bacteria, additional thatch accumulation will slowly break down over time so the height stays at that normal level. De-thatching is only called for when the thatch layer exceeds the recommended amount and the excess needs to be removed and disposed. If thatch accumulates to a thicker level, it can be a problem by preventing water to penetrate into the soil, causing grass roots to actually grow up into thatch seeking water and preventing fertilizer from reaching the root system. The biggest benefit of having a thatch layer in a healthy lawn is the thatch will decay naturally, slowly providing nutrients to the lawn.
What is thatch?
Thatch is the naturally occurring, tightly interwoven layer of living and dead roots, stems, stolons, and rhizomes between the green blades of grass and the soil surface. A common misconception is that grass clippings are thatch or can cause thatch, which is not correct. A thin layer of thatch can be beneficial to the lawn because it helps to limit weed seed germination, reduce water evaporation, and protects the lawn from frost damage. A little thatch can also improve the wear tolerance of a lawn, however, thick thatch layers can limit or prevent water, air, and nutrients from penetrating the soil, causing reduced root growth and increased potential for drought stress. Too much thatch can also aid in fungal growth and insect infestations.
In an unhealthy lawn with too much thatch, the soil may be compacted, making it harder for bacteria to reach the surface to break thatch down, which is essential in maintaining a normal thatch layer. When the thatch layer is too deep, the lawn will begin to suffer and thin. Lawns with heavy thatch tend to have a shallower root system, making a beautiful grass harder to grow or maintain.
One easy solution to excess thatch is to aerate the lawn, which removes many two inch plugs from the lawn, which include thatch from the thatch layer as well. The holes left from aerating allow bacteria to be drawn up to the surface so it can do it's job of breaking down the thatch layer. Lawn aeration isn't always the answer for thatch build up, but if the thatch layer is just slightly more than 1/2 inch, lawn aeration could correct the problem.
Don't get carried away with de-thatching, having no thatch layer isn't the goal either. Having no thatch can make the lawn more susceptible to drought and heat stress. Thatch not only provides nutrients, it also helps shade and protect the crowns of the grass plants and helps conserve moisture.
When To Dethatch
The following are some signs to look for that indicate excessive thatch and the need for de-thatching.
- The grass is green on top but brown underneath
- If the grass feels "spongy" to walk on
- It looks dead and scalped when you mow
- The lawn is thinning and off-color
De-thatching is best done in early spring or early fall. This allows the lawn plenty of time to recover before winter, but also avoids the stressful times of summer drought and heat. If dethatching is being combined with over-seeding we recommend doing it in early spring to allow the new seedlings plenty of time to get established before the summer drought and heat. Late summer/early fall also remains the optimum time for any over-seeding because you avoid the summer heat and drought and the new seedlings do not have to compete with the spring germinating weeds.
Tips for preventing thatch build up
The following tips may help you avoid a labor-intensive or costly de-thatching of your lawn
- Infrequent but thorough watering
- Avoid frequent and shallow irrigation on established lawns.
- avoid excessive amounts of nitrogen.
- Keep the mowing height at 2.5" to 3" all season long
- Bag clippings ONLY if mowing creates excessively long clippings
What Does De-thatching Cost?
De-thatching a lawn is a time consuming process with most of the work being the thatch clean up that is left on the lawn after the machines make their passes. The cost of de-thatching varys depending upon the size of your lawn and amount of thatch to be removed. The minimum price for de-thatching is $150, but for a more accurate price, please request an estimate for this service or call our office.