If you had crabgrass last year, you have thousands of seeds
in your lawn just waiting to sprout. And once that happens, you'll likely be
looking at crabgrass again all summer.
All it takes is one itty-bitty crabgrass seed to create a monster like this one.
Spring is the time to apply crabgrass
preventer (aka preemergence treatment) to your lawn. It works by preventing
seeds from germinating. You have a very short window of time to apply the
preventer. Miss it and you're stuck with another year of a crabgrass-choked
yard. Here's why.
germination is triggered by soil heat. That's why you'll find crabgrass sprouting
first near sidewalks, driveways or any other warm surface that heats up the
soil nearby. Crabgrass usually sprouts after your lawn greens up in the spring.
Applying crabgrass preventer too early is a mistake—it might lose its
effectiveness before the seeds come to life. So you should apply preventer
between your second and third mowings. The first treatment is by far the most
important, but you'll have other Johnny-come-lately seeds that hadn't woken up yet
and won't be affected by the preventer. That's especially true for seeds that
are in cooler soil. That's why you should apply a second treatment a few weeks
later. Once you do that, you'll have very little crabgrass the rest of the
Applying crabgrass preventer is as easy as filling your spreader and taking a stroll around your yard. If you're worried about getting preventer in flower or vegetable seed beds, use a drop spreader rather than a broadcast spreader. Broadcast spreaders like the one shown spew material over a wide area rather than dropping it directly below the spreader.
is as simple as filling your broadcast spreader with crabgrass preventer and
pushing it around your yard, just as you would with granular fertilizer. But
beware. Preventer stops ALL seeds from germinating. If you get it on your
vegetable or flower garden where you intend to plant seeds, nothing will grow! And
don't plant grass seed within eight weeks of applying crabgrass preventer, or the
grass seed won't germinate either.
to apply the crabgrass preventer again next spring. You'll still have dormant
crabgrass seeds in your lawn raring to go—they can stay viable for years.
— Travis Larson, Senior Editor