Dethatching rakes are an invaluable lawn care tool. Even the healthiest lawns need to be dethatched periodically. If the thatch layer of decomposing leaves, grass clippings and moss becomes too deep, it inhibits the flow of water, nutrients, air and fertilizers to the grass roots. Dethatching rakes are used to remove the thatch before it becomes to thick, improving nutrient and water movement, promoting deeper roots and encouraging new grass growth.
There are a few different types of dethatching rakes, also known as power rakes or lawn rakes. While they vary in size and shape, each has several sharp-sided blades that get into the thatch, cutting through it or pulling it out. The three main types are manual, power and tow-behind.
Manual rakes or hand thatchers look the most like a typical rake except the tines are much sharper along each edge. These rakes are used similar to other rakes. Put the bottom of the tines onto the top of the soil line and pull the rake back toward your body. Use small, quick strokes in multiple directions to remove the thatch from one small area before going onto another.
While these tools start at $10, it is better to spend more ($25-$30) for a quality one that will last you 10-15 years. Even if you plan on dethatching another way, having a manual one around is a good idea for touch-ups or working on problematic areas.
Power rakes have electric or gas motors and more closely resemble a lawn mower than anything else. Along the bottom is a bladed reel that slices through the thatch layer. The rake width is around 18”-24” with the machine being a couple inches wider on each side. Since they are expensive to buy ($1000-$2000 and up), most people hire a professional or rent a machine and do it themselves. It will probably cost around $50 for a four-hour rental, which is enough time to do most residential lawns.
Whether renting or buying, look for a machine that has five to six adjustable blade heights so you can pick the right one for your lawn. If it is too deep, it will pull out a lot of grass plants with the thatch. Too shallow means it won’t be able to get into the thatch layer well enough to remove it. After setting the blade height, push the rake over the grass twice in right angles or crosswise for the most thorough dethatching.
If you have delicate cool-season grass or you want a gentler dethatching process, use a power rake with a spring tine attachment instead. Other features to consider include a collection container that fills with moss, thatch and other debris as you go so there is less raking to do afterwards. Also, many have a seeding attachment so it can be used to overseed as well.
Dethatching rakes that are designed to be pulled by a riding lawn mower or tractor make quick work of dethatching a large area. Wider than other rakes, they cover more area more quickly. Tow-behinds start at $150-$200. Make sure to find one that will properly attach to your lawn mower or tractor hitch. After attaching it, drive in long rows then short ones over the grass, watching for any obstacles. Look for a rake with a tine design that allows you to turn when the tines are in the ground. These are much easier to use and maneuver.
Some lawn mowers can be converted to a dethatcher with an attachment. These attachments are cheaper to purchase than a power rake and will make your lawn mower more versatile.
General Dethatching Tips
Dethatching is best done when the lawn is not soggy or bone-dry, but a happy medium. The lawn should be mowed shorter than normal for the best results. You can mow and water the lawn the night before if you need too.
Learn more about lawn aerators.