The Zone 6b Lawn Care Calendar — Month by Month
Posted April 2026 · Metro West Lawn & Landscape
St. Louis is USDA Zone 6b. That means our growing season runs roughly April through October, with cool-season fescue dominant in most lawns. Here’s what your lawn actually needs every month — and what we do for our customers.
January & February
Lawn: Dormant. Don’t walk on frozen turf — it damages the crowns. You should be doing: mostly nothing. Service equipment, sharpen mower blades, plan your spring projects.
March
Lawn: Starting to wake up. Soil temps climbing toward 50°F. You should be doing: first cleanup of winter debris, dethatching IF you have heavy thatch, pre-emergent crabgrass treatment when forsythia blooms (mid-to-late March in Metro West), and our recommended spring liquid aeration jumpstart.
April
Lawn: Active growth begins. You should be doing: first mow when grass hits 4 inches, set mower height to 3.5". Begin weekly mowing schedule. Pre-emergent should be applied if not done in March. First fertilizer application toward end of month.
May
Lawn: Peak spring growth. You should be doing: weekly mowing — never cut more than 1/3 of the blade in one mow. Spot-treat broadleaf weeds. Mulch beds for the season. Last solid window for landscape installation before summer heat.
June
Lawn: Heat starts setting in. You should be doing: raise mower height to 4 inches. Stop fertilizing nitrogen — you’ll burn the lawn. Water deeply and infrequently (1 inch per week, ideally early morning). Watch for fungal disease in shaded zones.
July
Lawn: Survival mode. Most cool-season fescue goes semi-dormant. You should be doing: minimum interference. Mow at 4 inches. Water if no rain for 7+ days. Don’t fertilize. Don’t aerate. Don’t plant. Just keep it alive.
August
Lawn: Same as July — surviving the worst of summer. You should be doing: patience. Plan your fall aeration appointment NOW (we book up early). If your lawn is wrecked, do not panic — fall aeration + overseed will bring it back.
September
Lawn: The recovery month. Cool nights, warm soil, fresh rain. You should be doing: aeration + overseeding window opens mid-month. Drop mowing height back to 3.5 inches. Resume light fertilization. This is your lawn’s best chance to recover for next year.
October
Lawn: Peak fall growth. You should be doing: THE month for aeration + overseeding if you didn’t do September. Heavy fertilization (lawn is storing energy for winter). First leaf cleanups. Last cuts at gradually lower heights.
November
Lawn: Slowing down, going dormant. You should be doing: final fertilization (winterizer formula, late month). Final mow at 3 inches. Major leaf cleanup. Fall landscape installation window for new beds, hardscape, and tree planting.
December
Lawn: Dormant. You should be doing: not much. Last leaf pickup if needed. Drain irrigation if you have it. Plan your spring landscape projects.
The two things most homeowners get wrong
Wrong thing #1: cutting too short. Mowing below 3 inches stresses the roots. In summer, anything below 4 inches will scorch your lawn within a week. Higher mowing = deeper roots = drought tolerance.
Wrong thing #2: fertilizing in summer. Nitrogen forces growth, growth requires water, water doesn’t exist in July, lawn dies. Save your fertilizer money for fall when the lawn can actually use it.
Want us to handle the calendar?
Our weekly mowing program covers the mowing, edging, trimming, and blow-off. Our separate 5-step fertility program handles feeding and weed/grub control — timed to the season. Most customers run both together. You don’t need to track any of this. See the program here.
One weekly program. Everything included. Free quote in 60 seconds.
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