Every year at this time we start to field calls about crabgrass.
Crabgrass loves the heat, especially around pavement, interlocking and anywhere the sun exposure is at a maximum on your lawn. Smooth crabgrass is light green in colour and can ruin the uniform appearance of your turf almost over night.
I wish I had better news for you concerning this weed, but I don't. There is no post-emergent crabgrass control on the market in Ontario.
What about pre-emergent?
You can waste your money on corn gluten every April/May if you want, but after giving it the old college try for a few years when the by-law was implemented, I would not be one of those people.
Corn gluten is expensive, must go down at 20lbs per 1,000 square feet, only works for about six weeks until you get crabgrass anyway....yeah...so no.
We already give the best instruction to our customers at the beginning of every season when we advise raising the mower height to two and a half inches and by June to three inches. This helps keep the soil temperature cooler and the spread of this weed less likely.
For the most part, the lawns we see with crabgrass are, generally, cut too short.
Still, there are no guarantees and unless you want to pull relentlessly until this annual weed dies-off in the fall, there aren't any alternatives.
That is why mowing height is so important along with over-seeding every fall. Create a strong and healthy root system able to withstand the crabgrass invasion and you'll be much happier when Mother Nature brings the heat.