KC Gardens

How low should you mow? Ignore bad advice

Tall fescue
Tall fescue

From Dennis Patton:

The last few weeks I have been very outspoken about practices performed by some local tree services. Well, this week I am going to continue down the road of taking on the green industry. This week I am going to switch my soapbox from trees to lawns.

Over the weekend I saw a news segment that recommended mowing your lawn low to get it ready for the spring season. There is no way around it, that is just bad advice. Let me explain why.

Mowing the lawn short at the start of the season seems like a really good idea. The low mowing height will cut away the winter dead and pick up all the leaves, leaving the grass ready for spring green. Who doesn't want to have the greenest lawn on the block? But here is the rub.

Mowing low in the very early spring or late winter does remove the winter layer of debris. Mowing low also removes much of the debris that is also shading the soil. You may ask what's wrong with that. The problem is low mowing opens the soil up to more sunlight. It is this light penetration that is the problem. Sunlight reaching the soil will result in the germination of more weed seed. Simply put, low mowing, or scalping the turf, results in more summer weeds.

Not sold yet on why you should not scalp in the spring? Here’s another reason; it damages the crowns of the plants, resulting in slowed recovery and poor spring growth. The crown, or growing point of the grass needs protection and new spring growth to help conduct photosynthesis. This ability to generate new growth produces the green-up for the entire summer, not just for the short term.

There’s one more problem. If you mow low, exposing the crowns, and we then get a harsh, cold spell, the grass has lost its blanket of protection resulting in crown injury and slower recovery.

So what do you do at the first mowing of the spring? Extension recommends simply dropping the mowing height one notch on the old mower. Last year you should have been mowing around 3 inches. So drop it a notch, around 2 ½-inches. This is all that is needed. Even this lower cut will remove the dead brown grass blades, suck up leaves and prepare the lawn for the spring period. What it also does is leave a thin layer of thatch to cover the soil, decreasing sunlight from reaching the soil. Why is the light and soil such as big deal? Remember, weed seeds such as crabgrass require light for germination. No light, no weeds.

Okay, week three on a soapbox rant but hopefully you will see that my goal is simple and honest. I want you to have the best lawn and landscape with the least amount of work. I also don't like to see people waste their hard-earned money. So ladies and gentlemen get ready to start your engines as mowing season is a few weeks away. But be prepared with good information, not harebrained, old school ideas.