Columbia homeowners know the frustration — a lawn that looks fine in April turns into a patchy, light-green mess by July. Crabgrass is almost always the reason, and it's almost always preventable with one well-timed March application.
Crabgrass seeds germinate when soil temperatures hit 55°F — typically late March to early April in Columbia. Pre-emergent herbicide must be in the ground before that threshold is crossed. Once seeds germinate, pre-emergent does nothing. Right now, in early March, is the only time this works.
Columbia's pre-emergent season starts March 1 — don't let it close
Call for a FREE EstimateCrabgrass thrives in exactly the conditions common across Columbia — thin turf from summer heat stress, compacted clay soils, and south-facing slopes that warm quickly in spring. Areas like Long Reach, Owen Brown, and Wilde Lake see some of the worst infestations in Howard County precisely because of these soil and sun-exposure patterns.
The biology is ruthless. A single crabgrass plant produces up to 150,000 seeds before dying in the first frost. Those seeds overwinter in your soil and germinate again the following spring — which means every summer you skip prevention, next year's problem compounds. Columbia lawns that go two or three seasons without pre-emergent often require a full renovation to recover.
The seeds that dropped last fall are sitting in your soil right now. Pre-emergent creates a chemical barrier at the soil surface that kills them on contact before they ever emerge. Once you see green crabgrass shoots in May or June, the window has already closed — and you're looking at a far more expensive post-emergent treatment with half the effectiveness. Act now while the barrier still works.
Greenlawn Inc provides crabgrass prevention across Columbia's villages and surrounding Howard County communities:
Crabgrass seeds respond to soil temperature, not the calendar. We monitor actual Howard County soil readings and apply when soil approaches 50°F — before the 55°F germination threshold is crossed.
Pre-emergent creates a thin chemical layer at the soil surface. When crabgrass seeds germinate, the root tip contacts this barrier and the seedling dies before it ever breaks ground — with zero effect on established grass.
Consumer pre-emergents hold for 6–8 weeks. Our commercial-grade products hold 10–12 weeks — fully covering Columbia's entire germination window through May without a second application.
We apply pre-emergent alongside spring fertilizer in a single visit. Your lawn gets nutrition for early green-up while the barrier goes down simultaneously — efficient, and no extra traffic on your property.
Once crabgrass has germinated — usually visible as light-green clumps in May — your only option is post-emergent control. It costs two to four times more, requires multiple applications, and tops out at around 70% effectiveness. Worse, surviving plants still produce thousands of seeds before the first frost, guaranteeing next year's problem is larger than this year's.
The only way to break the cycle is a correctly timed pre-emergent application every March. Each year you get it right, the seed bank in your soil shrinks. Within two to three seasons of consistent prevention, Columbia lawns that once looked terrible in August start looking dramatically better.
Clay soils actually hold pre-emergent longer than sandy soils — an advantage in Columbia. The barrier tends to persist well through the full germination window. The challenge is ensuring even application coverage without gaps, which is where commercial spreader equipment earns its keep. Uneven coverage in clay means crabgrass finds the thin spots and exploits them all summer.
You can, but the two most common failure points are timing and coverage. Consumer products are often applied too early based on calendar date rather than actual soil temperature, and homeowner spreader equipment frequently leaves gaps. Our commercial products also last 4–6 weeks longer than store-bought formulas. Most homeowners who try DIY for a year or two come back to professional service after a bad crabgrass summer.
Pre-emergent stops all seed germination — it doesn't distinguish between crabgrass and desirable grass seed. For small, isolated bare spots we can discuss applying before seeding those areas. For larger areas, we typically recommend fall overseeding instead, which is the better season for turf establishment in Maryland and lets you get full spring pre-emergent coverage.
We recommend keeping pets and children off the treated area until it has dried completely — typically 2–4 hours under normal conditions. Once dry, the product is bound to the soil surface and no longer poses a contact risk. We'll give you specific re-entry guidance when we complete the application.
In most cases, yes — noticeably so. A well-timed application in a lawn with moderate crabgrass history typically results in 90–95% less crabgrass through summer. The difference is most obvious in July and August, when untreated neighboring lawns are overrun. If your lawn has a heavy seed bank from years without treatment, the first year reduces the problem significantly; by year two or three of consistent prevention, the results are dramatic.
The March window is open right now. Every day that passes is a day closer to the soil temperature that makes pre-emergent ineffective. Greenlawn Inc has been protecting Columbia lawns from crabgrass since 1986 — we know exactly when to apply and we're ready to schedule your property today.
One March visit. A summer of clean, green turf.
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Greenlawn Inc has protected Columbia, Ellicott City, and Howard County lawns from crabgrass since 1986 — with professional pre-emergent applications timed precisely to Maryland soil conditions and 39 years of local experience.