The lawn weed, crabgrass (Digitaria spp) is a warm-season annual weed, which means it reproduces by seed.
How do you kill crabgrass? The short answer: applying pre-emergent herbicides at the right time is the best way to kill crabgrass. Most lawn care companies will include this in their fertilization and weed control lawn care programs.
There are many different types of pre-emergent herbicides for killing crabgrass. “Weed and feed” products often contain pre-emergent herbicides, although some question whether their concentration is strong enough to be effective. Here are 2 types of pre-emergent herbicides: Dimension and Tupersan.
DOs and DON’Ts
Preemergent Herbicides for Killing Crabgrass: When to Apply
To get rid of crabgrass it helps to know its life cycle. When spring soil temps (at a depth of 2″-3″) reach 55-60 degrees Fahrenheit, the first crabgrass seed will germinate. From mid-summer to fall, crabgrass produces seed. The crabgrass plants (but not the seeds) are killed by frosts in autumn.
Pre-emergent herbicides come in either granular or liquid form and kill crabgrass seedlings as they germinate. If you are going to core aerate or dethatch your lawn after applying pre-emergent herbicides, these ACTIONS WILL BE FOR NOT. Aerate lawns beforehand, instead.
Pre-emergent herbicides kill crabgrass at a specific time: before its seedlings emerge. Successfully getting rid of crabgrass in this manner, timing is essential. Apply pre-emergent herbicides before germination, but not too far ahead. Crabgrass germination coincides approximately with the blooming of the lilac bushes.
Types of Pre-emergent Herbicides for Killing Crabgrass
*Dimension (active ingredient, dithiopyr) is safe to use on most lawn grasses (check label first) and provides long-lasting coverage — an important consideration, since not all crabgrass seed germinates at once. Thus Dimension will kill later-germinating crabgrass, too. Dimension also displays some effectiveness as a post-emergent herbicide.
*Tupersan (active ingredient, siduron) is worth mentioning because, unlike other
pre-emergent herbicides, it will not damage germinating lawn grass seed. In fact, its active ingredient is often combined with starter fertilizers. Alternatively, for newly-seeded lawns, wait until after 3 mowings (or 3 months, to be on the safe side) before applying pre-emergent herbicides.
Using Pre-emergent Herbicides for Killing Crabgrass:
Do:
*Irrigate afterwards: water activates pre-emergent herbicides.
*Re-apply pre-emergent herbicides, if you question your product’s coverage. Because
crabgrass seedlings do not all germinate at once, re-application can kill some of the
later-germinating crabgrass.
*Follow label directions and apply the proper rate. Measure the lawn area and calibrate your spreader carefully. The lawn weed, crabgrass (Digitaria spp) is a warm-season annual weed, which means it reproduces by seed.
How do you kill crabgrass? The short answer: applying pre-emergent herbicides at the right time is the best way to kill crabgrass.
Don’t:
*Dethatch or aerate the lawn after applying pre-emergent herbicides.
*Apply pre-emergent herbicides on new sod.
