Spring is almost here and there is a lot of advice about how to maintain your lawn and get it ready for warmer months. That’s why our very own expert agronomist, Dr. Rodney St. John wanted to bust some myths about lawn care and here’s what he had to say.
Myth: You should mow at the same height year round
Reality: There are two main arguments in favor of keeping your mower’s height high in the spring. First, there’s the risk that if you lower your mower too low, you can scalp the lawn—damaging both the grass and your mower. The second is that it can be easy to forget to raise the mower back up for the summer months when the grass isn’t growing as quickly.
I frequently advise people to lower their mower one notch in early spring and then raise it back up for the hotter days of spring and summer. Then I recommend lowering it back down one notch for the fall.
For cool season lawns (tall fescue, bluegrass), there isn’t a major agronomic benefit to lowering it one notch for the first mowing. It is mainly for aesthetics. By lowering it one notch, you will remove much of the brown leaf tissue making it easier to see the new green blades, which makes your lawn appear greener, quicker. For warm season lawns (bermuda, zoysia, buffalo), mowing it a notch lower will allow more sunlight to reach the ground and warm up the soil quicker, thus decreasing the amount of time it takes for the grass to green up and get growing.
Now for the caveat; lowering the mower one notch will increase the amount of sunlight that reaches the ground. So if your lawn is thin and weak, this could allow more weeds to germinate. You can prevent this by making sure the lawn is thick and healthy and by using a pre-emergent herbicide.
The bottom line is, you don’t HAVE to mow it shorter, but doing so can improve the appearance of your lawn. Just remember to raise it back up after that first mowing.
Myth: Grass clipping cause thatch—bag them.
Reality: The facts are that grass clippings do not cause thatch. Thatch is made up of decomposing stem, root, rhizome, and stolon tissue—NOT grass clippings. In fact, it can be beneficial to leave your clippings laying in your yard because they contain small amounts of nutrients that can help your fertilizer maintain health and color. So while it’s not a bad thing to bag your clippings, it shouldn’t be done because you’re worried about thatch.
Personally, I think the main reason many people bag their clippings is because they don’t mow often enough. Follow the 1/3 rule of mowing; never remove more than 1/3 of the leaf tissue when you mow. So if you are maintaining Kentucky bluegrass at 2 inches, don’t let it grow taller than 3 inches before you mow. If you are keeping your tall fescue at 3 inches, mow it before it reaches 4.5 inches. This will keep your clippings small and easily dispersible. It will also be the least stressful on the grass.
But this means you will have to mow more often during those rapid growing times (in the spring and fall for cool season grasses and in the summer for warm season grasses). It might mean mowing every 4-6 days instead of the once-a-week most people mow.