Spring Lawn Tips: When to Mow and Dandelions

By Allyn Hane - "The Lawn Care Nut"
May 5, 2018

Most of you with cool season grass types (Kentucky Bluegrass, Turf Type Tall Fescue, Rye) are just waking up to the real spring. The weatherman is done teasing you with warm days followed by ice storms, and your lawn is stretching tall looking for sunlight. You’re wondering, “When should I start mowing?”

Lawn mower in dark green grass

When to Start Mowing In Spring

This one is easy: you can mow whenever you want as long as the ground is not frozen and there is no frost on the grass plants. The crowns of frozen plants can be broken and permanently damaged, so stay off until the day’s sunlight softens everything up. Other than that, feel free to get out and #EnjoyTheMow whenever you like.

If there are excessive leaves on the lawn, it’s a good idea to bag those up and use them for mulch elsewhere. It’s critical in spring to get every bit of sunlight you can onto the grass plants and penetrating into the soil.

Additionally, you should lightly rake out areas where the turf has been matted down from piles of snow or over-winter foot traffic. Once again, let’s help the lawn get more sunlight and airflow as early as possible.

For that first mowing, it’s ok to take your height setting down just a bit to once again, allow more sunlight to get to the soil quicker. For most cool-season lawns, 2.75” cut for the first of the year is going to be just fine - but be sure to get that height up to 3.5” or even 4” quickly for your next few mowings!

Dandelion Weed Control In Spring

I get a lot of questions this time of year regarding weed control so let me give you some basics.

There are two terms I need you to learn and understand:

  • Pre-Emergent
  • Post-Emergent

Pre-emergent weed controls are designed to prevent weeds and weedy grasses from entering your lawn. This means they have to be applied before the weed seeds germinate. You can read more details on pre-emergents here, but there are some follow-ups we should cover now.

First off, there is no pre-emergent control for dandelions.

Dandelions and a dog in the lawn

I call out dandelions because they are about to blow up in the next couple weeks and every year when that happens, I get people emailing asking “How come I have dandelions? Did my pre-emergent fail?”

There are a couple pre-emergents labeled for dandelions but they are marginally effective and not readily available or affordable for homeowners anyway. Some are not labeled for use in lawns.

The other thing to know about dandelions is that they are perennial. This means the same plant comes back year-after-year. So if you had thousands in your lawn last year, you will have those same thousands in your lawn this year, they will just be bigger, and meatier. Time to explore a post-emergence control.

Post-emergent weed controls are those that target weeds that have already shown themselves and started to grow. This is where you will have to address your dandelions and I recommend you do it in a targeted fashion practicing integrated pest management.

In a nutshell, don’t use a weed-n-feed type product across your lawn hoping for results. If you have weed problems, get a concentrated liquid, mix in a pump sprayer according to label directions, and spot or zone spray. This way you only use the weed control where it’s needed, and don’t waste it where it’s not. Most box stores have inexpensive weed controls labeled for dandelions. Hint: dandelions are easy to kill, they are weak.

Also, consider the overall thickness of your lawn and the severity of the dandelion infestation. If you only have a few here and there, consider hand pulling them and forego the chemical altogether. Fertilizing regularly with my friend Milorganite will also get your lawn racing quickly to thickness which can also help you compete with dandelions and other weed invaders. As you all know, I really like to push my lawns - hard.

If you would like more information on Dandelions, pre-emergents, and a whole lot more, sign up for my free weekly newsletter where I give out all kinds of lawn tips each week. Lastly, did you enter the contest yet? You know that your house and lawn could be on the bag of Milorganite in 2019 right? You need to see this!

And with that, I’ll see YOU, in the lawn!