When to Rake or Scarify

Raking or scarifying your lawn, whether it be for thatch or moss, is an extremely beneficial procedure in the long term, but in the short term, it can make a right old mess of it. Though it will recover and be better than ever, getting there in the shortest possible time is our ultimate objective.

So often, I see people doing a thoroughly good job with their scarifying but at the wrong time of year or in the wrong conditions. This means the lawn is an eyesore for weeks, if not months. You may also cause damage to your otherwise healthy grass plants, worsening the problem. It makes me shudder!

Time your programme according to the lawn's ability to recover. This means warmth, sun, and rain while avoiding cold, heat, or drought. In other words, you need good growing conditions, and if your lawn isn’t growing well before scarifying, it won’t grow well afterwards, leaving you with a much-disfigured lawn!

Spring: Raking & Light Scarifying

Light de-thatching (read here for more info on what thatch is, exactly) or scarifying and moss removal can be done in spring or autumn. Spring generally means sometime in April, just as things warm up, thereby increasing the growth and recovery rate, but before the heat and dryness of summer slow things down. Autumn would generally be late August or September, as the rains start but before the cold sets in.

Autumn: Heavy Scarifying

Try to stick to the autumn period for heavy thatch or moss infestations requiring deeper scarifying or raking. Why?

Heavy raking or scarifying will seriously thin the lawn, exposing soil in many places. This makes an ideal seedbed not only for overseeding with new and improved grass seed but also for all the weed and weed grass seeds floating around. By confining this intensive treatment to August or September, you will avoid most of the year's weed seeds. If you do this in spring, you’ll replace your moss or thatch problem with a weed problem! There are a few exceptions when spring is the best time:

It is better to rake or scarify in spring if you could not do it the previous autumn, perhaps due to bad weather, rather than put it off. Putting it off from autumn to autumn could mean you’ll have a bigger problem than a few weeds!
If the area to be scarified is shady. Shady areas will thin over winter and thicken up from spring onwards. Therefore, if you scarify in autumn, you’ll make things worse.
If the area is under trees, the shade from trees and the autumn fall of leaves will reduce grass health and vigour. However, in spring, late March through April, the trees are bare, allowing maximum light to your lawn, enabling good growth and maximum opportunity for new grass seed to grow.

Ready the Lawn for Scarifying or Raking

Planning is important. You need short, dry grass for raking or scarifying, so gradually lower the grass height over a week or two before hand. This doesn’t shock the grass and allows air to penetrate deeper into the turf, helping dry it.

If you have any weeds in your lawn, you can manually remove them, but don't use any weed killer. Scarifying within a few weeks of weed killer application disrupts the weed killing process and, in addition, may cause seed germination issues if you are going to overseed after scarifying. Scarifying can help control some creeping weeds, though.

The final bit of preparation is good soil moisture so the lawn recovers as quickly as possible. If there is too much (soft ground) or too little (dry hard soil), you must either wait until the conditions improve, assist them in improving, or not rake or scarify.

The day before attacking the lawn, mow it as close as possible without scalping. Long grass resists the scarifier, ultimately creating more rubbish to collect. Dry grass and moss make life a lot easier as well. Plan to rake on a dry day with no dew around. The afternoons are often best. If the weather doesn’t play ball, keep the grass short until you get another raking opportunity.

You can continue reading our How to Scarify & Rake a Lawn guide.