Like most of the services provided in the lawn care industry, timing is everything and results take time. Crabgrass prevention is exactly one of those services that is very dependent of time!
First, we need to understand what crabgrass is and when it germinates. Proper identification can begin with simply understanding the stages of crabgrass growth. Crabgrass typically begins to germinate around mid-April in the Midwest. These newly germinated plants are very small and produce one leaf at first.
When we are called to lawns in early Spring with complaints of large crabgrass plants we immediately know that crabgrass has only just begun to germinate and the problem has only been misidentified.
If conditions are right, crabgrass will continue to germinate throughout the summer. According to “Turfgrass Weed Control for Professionals” published by Purdue University, it only takes 1 square foot of crabgrass to produce over 10,000 seeds, making crabgrass an annual problem if not controlled properly.
Once crabgrass has germinated, one plant can become very large with multiple tillers.
Crabgrass In Lawns
One of the most common spots where crabgrass appears in lawns is along the edges of sidewalks or driveways and in tree rows. These areas often are high traffic with stress on the desired turf. Over time, desired turf will become thin and bare. As this happens, crabgrass has an easier time germinating with less competition.
Understanding the life cycle and growth habits of crabgrass helps us to determine the best course of action for treatment:
Pre-emergence Control of Crabgrass
The most cost effective and easiest time to control crabgrass is before it even germinates. We select a product specific to our climate that has proven through scientific trials to provide the best results. By applying a preemergent to the lawn, a barrier is formed that will help to prevent crabgrass from germinating.
Sometimes, crabgrass will still germinate even after the pre-emergent is applied. We call this “breakthrough.” Breakthrough can happen because the soil is disturbed, unfavorable weather conditions, improper application technique or bare or thin ares in the lawn. When breakthrough occurs or no pre-emergent application was applied, a post-emergence application will need to be applied.
Post-emergence Control of Crabgrass
The post-emergence application to control crabgrass is more expensive and time consuming. Because the crabgrass is usually larger by this time, it will take a special product to control. Missing the Early Spring Application can prove to be costly in July!
Cultural Control of Crabgrass
A cultural control is a way to control a weed or pest by changing the environment or growing conditions. We suggest the following cultural practices to best control crabgrass.
- Proper mowing height of at least 3.5″
- Proper irrigation practices
- Proper fertilization program to promote healthy soil and turf
- Fall seeding, August 15th to September 30th, of areas or full lawn with a Turf Type Tall Fescue Blend
Crabgrass is one most noticeable and troublesome annual weeds we see in lawns. There are many factors that control the life cycle of crabgrass and many different ways to control it.
Even when all of these practices of a preemergence program and cultural practices are in place, homeowners may still see some crabgrass breakthrough during the year. Proper application techniques, plant identification, and product selection are vital to successful control.
If you have questions about or issues with crabgrass in your lawn, give us a call and we will be more than happy to help in any way we can.