If crabgrass ruined the appearance of your lawn last year, here are valuable tips from landscape maintenance professionals on how to prevent crabgrass infestation in your Wappingers Falls, NY, yard going forward.
What Is Crabgrass?
Crabgrass is a fast-growing annual weed that emerges in late spring. It’s an opportunistic plant that grows anywhere there is bare soil, adequate water, and sunlight. Contrary to popular belief, crabgrass does not kill or crowd out lawn turf although it does spread quickly. And for all appearances, it ruins the look of a well-manicured lawn especially in late summer. Crabgrass grows in clumps, which turn brown well before desirable lawn grasses. Cold weather kills the year’s plants, but the seeds remain and will germinate the following spring.
How to Prevent Crabgrass Infestation
Crabgrass control is an ongoing challenge. Proper lawn maintenance may not be sufficient to prevent crabgrass. There are three ways to control crabgrass:
Use pre-emergent herbicide to prevent the year’s “crop” from germinating and spreading.
Use post-emergent herbicide to kill any crabgrass before it goes to seed.
Maintain a healthy, thick lawn free of bare patches where crabgrass can take root.
Controlling crabgrass before it comes up is possible by using pre-emergent herbicides, which kill crabgrass seedlings. Keep a close eye on the weather and have pre-emergent herbicides applied earlier in the season if weather is unusually warm. Once ground temperature has reached a consistent 60 degrees—generally, when your trees and shrubs begin budding—or if the spring is very wet with mild nights, it’s time for “spring cleaning” to prevent crabgrass. Pre-emergent herbicide must be applied carefully and during specific times of year (both spring and fall), and is not suitable for use on newly seeded lawns or freshly installed sod.
Once crabgrass has appeared, pre-emergent herbicides won’t be effective. In this case, use post-emergent herbicides that kill the crabgrass plants, hopefully before they go to seed. These herbicides are carefully applied only to visible crabgrass to avoid damaging the lawn. After your lawn is treated with post-emergent herbicides, be on the lookout for newly germinated crabgrass, and follow up with spot treatments.
In some cases, several applications of herbicide will be needed to kill crabgrass that is well-established. All herbicide application must be done carefully to prevent injuring turf and any landscape plants.
If the lawn is mostly crabgrass, it may be advisable to do a lawn renovation in the fall. Consult a lawn care specialist if your lawn is overrun with crabgrass.
Preventing Future Crabgrass Growth
The best way to ensure that crabgrass doesn’t make an annual appearance is by maintaining your lawn, to prevent any unwanted weeds or grasses from moving in. To keep your lawn at peak health, it needs to be mowed frequently, with the mower setting at the highest recommended height. Keeping the grass taller prevents sunlight from reaching crabgrass seedlings. If the lawn is cut too short—more than ⅓ of the grass blade—the grass you want could be injured, leading to the exposure of any crabgrass seedlings to the sunshine they need to thrive.
The lawn should be watered deeply in long, heavy intervals. Shallow and frequent watering prevents deep root growth, and can result in grass that isn’t thriving, and patchy areas that invite crabgrass. Established lawns typically require about 1 inch of water per week, whether that water comes from irrigation or from rain or irrigation.
Also keep in mind that your grass should be fertilized annually (or more, as recommended by your lawn care professional) to promote healthy turf.