Mowing Height – There is no one-size fits all

In my world of answering gardening/horticultural questions, one thing has rung clear for the past 25 years, and that’s that most people are looking for a quick-fix, or one-size-fits-all answer.  Recently, this situation has reared its head when it comes to “mowing heights” for our turfgrasses along the Gulf Coast.

And since we work with three very distinct turfgrasses (St. Augustine, Bermuda & Zoysia) this truly falls into that world. One height of mowing doesn’t apply.  In fact, one mowing height doesn’t even apply to all St. Augustines all Zoysias.

Frankly, you have to experiment with mowing heights because of the different grasses and the different varieties within those grasses. The mowing height is also determined by how healthy your stand of soil is that the grass in growing in, and lastly because not everyone has the same type of mower.

I have a few rock-steady rules for mowing heights that you can apply starting this week, and then please don’t hesitate to make some adjustments.  Of course, there is one huge caveat to all these rules, and that’s if you have a mowing service doing the work for you. If you need them to raise their mowing height when they visit you, there are two ways I’ve found to make this happen.

First, and the most obvious is call the owner/manager/coordinator of that crew and tell them that you want the mowers (riding or push) to be raised at least one notch above what they normally come in with. If they refuse or act like they can’t, then fire them and find a crew that will. That’s pretty simple.

Or, you can do what I’ve done, and what I tell people to do in this situation when they call my radio show: If you know when they arrive for their weekly visit (most are very consistently schedule-motivated) be out there and ask them politely to raise the mower deck at least one notch. And be out there for 2-3 consecutive weeks, so that when they arrive at your house, they know to raise the mower deck.

So here are some of those Rock-Steady Rules:

  • For St. Augustine mow your grass at the highest or next to highest setting of the lawn mower deck.
  • For St. Augustine, don’t mow any lower than a 3 – 3.5-inch-high profile.
  • For St. Augustine with healthy soil profiles, you can and should mow at a 3.5 – 4-inch-high profile.

Have you ever noticed the lower the mower deck on St. Augustine grasses the more yellow the turf looks year-round?

  • For Bermuda grasses, you can and should mow at a 2 -2.5-inch-high profile.
  • For Thin-Bladed Zoysia grasses, you mow like its Bermuda at 2 – 2.5-inch-high profile.
  • For Wider-Bladed Zoysia grasses, you can mow like a St. Augustine at 3-inch-high profile.
  • Don’t rely on Fertilization Companies to tell you what height you should mow at, because national companies are using information they’ve accumulated from other turfgrasses throughout the country, and rarely studied on St. Augustine.
  • Local or even regional lawn fertilizer or turf install companies haven’t updated their information on mowing heights in over 30 years. Since then, we have a lot more Zoysia & Bermuda specific lawns.  You can be sure all their old advice is strictly on St. Augustine.
  • For Bermuda and Thin-Bladed Zoysia grasses, you should be mowing with a Reel Mower, one that cuts over the top as opposed to a rotary/helicopter type blade.
  • First mowing of the year can always be lowered a notch or ½ inch, to open up/aerate the lawn for the coming spring.
  • In the autumn months, if you’re experiencing a lot of tree leaves and want to essentially vacuum them up in a mowing, you can always lower your mowing deck by ½ inch.