What is crabgrass and how to deal with it?

by | Weed Control

Keeping your lawn in perfect shape is a difficult task that requires a lot of effort and precision. Seeing all that hard work disappear in a matter of weeks due to weed infestation is a confidence killer and a never-ending source of frustration for many homeowners.

Crabgrass is one of the most stubborn and resilient weeds and is quite challenging to deal with it. As an annual plant, crabgrass will grow, germinate, and die all within the same year. It is a warm-weather plant which starts germinating in spring, as soon as the temperatures reach 55 to 60 degrees Fahrenheit.

It is one of the biggest enemies of landscape and gardening enthusiasts and can do immense damage to the lawn within its short lifespan. While the plant lives for just a portion of the year, it can produce more than 150,000 seeds in that time frame. Seeds can survive in the soil and start growing the following year, beginning the cycle again.

Our lawn care enthusiasts at Yard Smart want to help you tackle your crabgrass problem head-on. We’ve prepared a short guide on how to kill crabgrass and prevent it from returning.

Crabgrass Lifecycle

To better understand how to tackle the crabgrass problem, it is essential to understand the lifecycle of the plant. We already mentioned that crabgrass is an annual plant that germinates, lives, and dies within the same year.

Germination happens in early spring when the soil reaches 55 to 60 degrees Fahrenheit. After germinating, crabgrass grows and produces up to 150,000 seeds that spread on the soil surrounding it. These seeds will grow into more crabgrass if left untreated, continuing the cycle.

It is essential to deal with crabgrass seeds before they start growing into adult plants. One of the most common ways to deal with weeds and prevent future growth is by regularly mowing your grass. Since crabgrass grows low, it is often impossible to remove it without completely ruining your lawn.

Preventing Crabgrass from Germinating

It is essential to stop the crabgrass seeds from germinating. Dealing with crabgrass after it has had a chance to grow will require much more time and effort, and it might take a full year or two to make sure that your lawn is free of crabgrass.

It is impossible to collect all of the crabgrass seeds on or in the soil by hand. The only option is to use a product that will stop them from germinating, such as pre-emergent herbicides. The primary role of these herbicides is to inhibit the germination and root development of crabgrass, therefore preventing the plants from popping up from the soil.

Pre-emergent herbicides are not without downsides, however. Most of them can also negatively affect the germination and root development of regular grass on your lawn. Be selective in which areas you will treat with the pre-emergent herbicides and closely follow the product’s instructions.

Give the treated area some time before reseeding it, ideally waiting at least 60 days before reseeding the treated areas with new lawn grass.

When to Use Pre-Emergent Herbicides

The timing of pre-emergent herbicide use is crucial. Pre-emergent herbicides only work before the crabgrass seeds germinate and start taking roots. If you miss this window, you will need to use an alternative way to deal with your crabgrass infestation. So, how do you know when is the right time to use pre-emergent herbicides?

By the time you spot the crabgrass seeds, it might already be too late to start with the pre-emergent herbicides. The most reliable way to determine the right time is to evaluate the temperature of the soil closely.

The best way to determine the temperature of the soil is by using an inexpensive soil thermometer, found in most gardening supply stores. Once spring temperatures start rolling around, make sure to start checking the temperature of the soil. If the temperature is 55 degrees or close to that, you should begin making preparations.

Follow the instructions on the pre-emergent herbicide bottle on how to dose the treatment properly. You will need to use the herbicide for 4 or 5 straight days to achieve the necessary concentration to prevent all the crabgrass seeds from germinating. Pick a quality pre-emergent herbicide product that will last for several months, because crabgrass seeds can germinate until summer when the soil temperature reaches 90 degrees Fahrenheit.

If you are reading this, chances are you are already past the germination phase, and crabgrass is a problem in your lawn. There are two methods for eliminating crabgrass from your lawn; an organic path or a path that includes the use of post-emergent herbicides. Both options are reliable but have some advantages and disadvantages.

Removing Crabgrass Organically (By Hand)

Removing crabgrass by hand is a labor-intensive process that many people detest, but it could be an ideal solution if you have isolated crabgrass problems in small areas of the lawn, or you would like to keep your lawn free of chemicals. Follow the steps below to begin removing the crabgrass from your yard by hand:

  • Water the areas where crabgrass is present and wait 30 minutes for the soil to soak in the water.
  • Use a weeding tool or pitchfork to remove crabgrass patches one by one. Make sure to remove the whole plant, including all of its roots.
  • Once you clear the area of all crabgrass, make sure to put a layer of compost on top of it. Make sure that compost mixes well with the existing soil for the best effect.
  • Take grass seeds and spread them across the soil. On top of the soil, place a layer of straw (ensure there are no weeds in it). The straw’s role is to prevent moisture from escaping the soil and to protect the new grass seeds from the birds.
  • Water the area several times a day and always make sure the area is moist.
  • Once the grass starts growing, it is essential to switch to deep watering. Crabgrass has shallow roots and feeds on the water at the top of the soil. By deep watering, you are depriving it of necessary moisture.
  • While you are dealing with the crabgrass problem, you should let the grass grow taller and mow it 2 ½ to 3 inches in height. This will help protect the grass lawn and allow less light to reach the soil where any remaining seeds of crabgrass remain.
  • Repeat the process as many times as necessary. It will usually take a full season before you can rid your lawn of crabgrass completely.

Removing Crabgrass with Post-Emergent Herbicides

An alternative to organic removal is the use of post-emergent herbicides. The process for using the post-emergent herbicides is identical to the one described for pre-emergent herbicides, so we will not go into too many details, but we will outline some things you should pay attention to.

  • Choose between selective and non-selective herbicides. Selective herbicides target a particular type of weed, while non-selective attacks all plants. The latter is a better choice if you would like to minimize potential damage to your lawn.
  • Make sure to mow at least two times and wait 60 days before reseeding the treated area.
  • Next year, in the spring, when the soil is the right temperature, use the pre-emergent herbicides to prevent the crabgrass from germinating again.

If you need expert help battling crabgrass on your lawn, give us a call at YardSmart, and our team of trained lawn care professionals will quickly diagnose the extent of the problem and outline a plan on how to return your lawn to its pristine condition.

Matt Higgons

Matt Higgons

It’s been over 40 years since Matt Higgons started his first lawn mowing gig with his closest friend in high school. He used that money to pay for a business degree at St. Lawrence College in Kingston, Ontario and had big dreams of starting his own company. He never realized that the very business he would dedicate his life to, was the same one that helped him pay for that education.

Related Posts

Lawn Watering Tips

Lawn Watering Tips

There is always a house or two in the neighborhood with impeccable lawns everybody envies. A healthy, beautiful green lawn is a statement piece of a house and creates a welcoming atmosphere, but the work and knowledge it takes to cultivate that sea of green is more...

read more
How to Deal With Clover on Your Lawn

How to Deal With Clover on Your Lawn

The sudden appearance of clover in the lawn tells us about the soil’s health. When clover is present in your grass, it indicates that the soil is low in nitrogen levels. Clovers flourish in low-nitrogen soil. Lawn properties require nitrogen in the soil, and if the...

read more