How to Prevent Crabgrass from Growing in Minnesota

Anyone who has a lawn in Minnesota knows what crabgrass is, but not everyone knows how to prevent crabgrass from growing or how to treat it once it is actively growing in your hard during the heat of the summer.

Here are our tips for Minnesota crabgrass control:

Biology

Crabgrass is a warm-season annual that grows best in the middle of summer when the temperatures are hot. It is not shade tolerant so you will see it congregate along sidewalks or in cracks, on the edge of the lawn by the road or your driveway. The plant winters over as seed and comes up in mid to late-May. The plant itself is killed off by fall frost.

How can I decrease the incidence of crabgrass without chemicals?

Keep a healthy lawn that is made up of a dense stand of grass. Keeping the grass healthy will keep it dense and have less surface area for opportunistic weeds such as crabgrass to invade. Make sure you are using the correct fertilizer and watering program for each season, if not, you could be placing undue stress on your lawn. Raise your mower height to 2 1/2 to 3 inches during the warmer months. This will increase shade on the soil surface and decrease the chance of the crabgrass seeds from germinating.

Why do I need to apply Crabgrass Preventer in spring?

A spring application of crabgrass preventer destroys crabgrass seeds as they start to germinate which makes them unable to take root and emerge from the soil. It is important to apply this chemical when soil temperatures are at 55 degrees to make sure the product is applied before the seeds have time to germinate when the soil temps reach 62 degrees. After the seeds have germinated, a pre-emergent (before the plant emerges from the soil), will no longer be effective. Read all directions on the package before you apply. Make sure to always water in your product after you have applied. There are only a select number of products that can be applied along with reseeding, ask one of our turf experts if you have any questions.

Are post-emergent herbicides for crabgrass effective?

There are chemicals that can kill crabgrass like Killz All, but it will also kill your lawn if the spray gets on it. Visit our knowledgeable and friendly lawn and garden experts for more information on the best way to restore your lawn if crabgrass has completely taken over.