Can I Seed My Lawn and Use Crabgrass Preventer this Spring?

Many lawns take a beating over the winter, and an aeration and over-seeding treatment can work wonders to give you a beautiful lawn all summer long.  

However, crabgrass is also a concern on lawns.

Crabgrass is the most common lawn weed in Pennsylvania, and it is primarily controlled with a crabgrass preventer, which prevents the crabgrass seeds from sprouting.

The Answer is, “Yes…But it needs to be done correctly.”

Crabgrass preventer can absolutely wipe out your newly sown grass seed  – for this reason, the work must be done correctly.

Options to Treat Crabgrass Without Harming New Grass Seed

Note: the information below only relates to the crabgrass preventer that we use on our customers’ lawns at Green Giant. Other materials may or may not give the same results.

The options are listed in the order we consider the most preferred to the least desirable.

Option 1:

• The fertilizer & crabgrass preventer are applied first
• Allow the materials time to settle into the soil for at least a few days (preferably with some rain)
• Then perform the aeration and over-seeding

This process has been studied extensively, and the results consistently show that the crabgrass preventer has very little, if any, adverse effect on the good grass seed.

Option 2:

• First, aerate and over-seed the lawn early in the spring, as early as possible (which is usually when the soil is dry enough)
• Wait until the majority of the grass sprouts are at least 1-2 inches tall
• Apply the crabgrass preventer

This process should eliminate any risk of the crabgrass preventer harming the grass seed (since the grass has completely emerged from the seed). 

The downside is that the process starts later in the season if the aeration & seeding is delayed. This might mean more watering as we get into the summer.

Option 3:

• Skip the crabgrass preventer
• Aerate & Over-Seed the lawn
• Treat crabgrass preventer with a post-emergent spray (after the plant is visible in the lawn)

Although crabgrass can be controlled with a “post-emergent” material after the plant is growing, it is less effective (especially in hot, dry weather), more expensive, and can damage surrounding good grass.  

Crabgrass preventer is considered to be the most critical component for effective crabgrass control. If possible, we recommend going with option 1 or 2.

What NOT To Do

• Do NOT spread seed on the ground, then apply crabgrass preventer. This will be a disappointment because most of the seed will not survive.
• DO NOT aerate and over-seed, then apply crabgrass preventer before the new seed has grown completely out of the seed. This will also lead to a failed seeding effort.

We are always here to help! Contact us for your free quote!

How Does Crabgrass Spread?

Crabgrass spreads primarily through prolific seed production, with a single plant capable of producing over 150,000 seeds. 

These seeds remain dormant in the soil throughout the winter and begin to germinate in the spring once soil temperatures consistently reach 55-60°F for several consecutive days.

In addition to seeds, established crabgrass plants spread laterally by tillering. This growth pattern creates dense patches that effectively choke out desirable lawn grasses. 

The seeds dropped by these plants in the late summer and fall ensure the cycle continues the following year.

Services We Offer

Lawn Care

Green Giant Home & Commercial’s Lawn Care services control weeds, build the thickness and density of your lawn, and protect it from being damaged by insects and disease, providing you with a great-looking, healthy lawn. 

We offer fertilization, weed control, liming, insect control, and aeration and overseeding. 

Visit our Lawn Care page for more information.

Tree Care

Green Giant performs Proper Diagnosis and Treatment of Tree & Shrub Problems, Insect & Disease Control (including Spotted Lanternfly), and Nutrient Management via Deep Root Fertilization to keep your plants healthy and thriving. 

Visit our Tree Care page for more information.

Vegetation Management

Green Giant’s Non-Lawn Weed Control services eliminate unwanted vegetation in a wide variety of locations for both residential and large commercial/municipal properties. 

Areas include fence lines, around obstacles to reduce weed eating, stone/gravel driveways & parking lots, swales, roadside/curbside vegetation management, and more.  

Find more information on our Vegetation Management page. 

Pest Control

Our full-service pest control division provides both Year-Round Service Programs that cover the vast majority of pests that you will encounter and also One-Time Corrective Services for pests such as bees, ants, termites, or mice. 

For more information, visit our Pest Control page.

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