Since power raking is meant to remove decomposed plant tissue, i.e., thatch, which gathers on lawn surfaces, the best time for power raking is in the early spring. This is because most gardeners lay down grass seed with the hope it will take root for later on that season and well into the coming summer months. This procedure has some definite benefits. If the intent is to grow a nice, healthy grassy lawn, then removing the excess thatch in the spring is recommended.

On the Other: Waiting Until Later in the Year to Power Rake

It is important to note that power raking, while useful in removing excessive thatch, will occasionally do some damage to healthy grass as well. Although many garden enthusiasts choose to rake in the early spring, sometimes it is advisable to wait until summer. This would be necessary if the type of grass that is desired is a warmer-season grass as opposed to varieties such as St. Augustine or Centipede grass, which grow best in lower temperatures.

Bottom Line

Whether the type of grass that is desired is a warm-weather variety or one better-suited for colder climates, the need for some power raking is crucial. This procedure is a proven means of removing at least some of the old thatch that has built up on the lawn's surface. A lawn will not thrive if it is raked excessively, nor will it do well if too many nutrients are removed from the ground because of too much rake usage. The key then is in moderation. If this is achieved, then the result will almost certainly be a beautiful grassy lawn to enjoy in the coming summer months.

Source:

Autumn Turf Tips

Pros and Cons of Power Raking

How to Revive Tired Grass