Key Takeaways
- Apply pre-emergent herbicide when soil hits 55°F for 3-5 days. Forsythia bloom is your natural signal.
- Cool-season lawns get their first fertilizer in April at 0.75-1 lb nitrogen per 1,000 sq ft. Fall feeding still matters more.
- Warm-season grasses stay dormant until soil reaches 65°F. Do not fertilize dormant grass.
- May is grub prevention month. A $20 application of GrubEx now prevents $200+ in damage repair later.
- Raise mowing height as temperatures climb. Taller grass shades soil, reduces weed germination, and promotes deeper roots.
Why Does Spring Lawn Care Matter?
Spring is the critical 8-10 week window that determines lawn density for the entire year. Pre-emergent timing, first fertilizer, and mowing setup all happen now.
Those 8-10 weeks between late March and late May set the tone for everything that follows. Get the timing right on pre-emergent, and you prevent 95%+ of crabgrass before it starts. Nail your first fertilizer application, and you fuel the thick growth that crowds out broadleaf weeds naturally. Set your mower at the correct height from day one, and your grass develops deeper roots before summer heat arrives.
Get it wrong, and the problems stack up fast. I watched a neighbor skip pre-emergent last year because "it wasn't that warm yet." By June, crabgrass covered nearly half his front yard. He spent $150 on post-emergent treatments and still had bare patches going into fall. The total cost of prevention? About $30.
The Three Pillars of Spring Lawn Care
- Prevent weeds: Pre-emergent herbicide creates a chemical barrier in the top half-inch of soil. It kills crabgrass and other annual weed seeds as they germinate.
- Feed the grass: A moderate spring fertilizer fuels early growth and density. The goal is steady, controlled growth, not a nitrogen explosion.
- Start mowing correctly: Your first mow height and frequency set the pattern for the whole season. Mowing too short in spring invites weeds and weakens root systems.
Spring is also the time to fix anything you missed in fall. Soil test not done? Submit one now. Bare spots from winter damage? Patch them before weed seeds claim that space. The clock is ticking from the moment soil temperatures start climbing, and every week of delay narrows your window.
What Should You Do in March?
March priorities are pre-emergent herbicide application when soil reaches 55°F, first mow of the season, and soil testing if not done in fall.
Cool-Season Lawns (Zones 2-7)
March is when the prevention window opens for Kentucky bluegrass, tall fescue, perennial ryegrass, and fine fescue lawns. Your primary target: get pre-emergent down before crabgrass germinates.
Pre-Emergent Timing
Soil temperature at 55°F for 3-5 consecutive days triggers crabgrass germination. Measure at 2-4 inch depth in a shaded spot, ideally in the morning. According to Purdue University Extension, pre-emergent herbicides must be applied before crabgrass germination begins at consistent 55°F soil temperatures.
Forsythia bloom is the classic natural indicator. When those bright yellow bushes start flowering in your neighborhood, soil temps are right. The window stays open for about two weeks, so you have some flexibility, but not much.
Recommended Pre-Emergent Products
- Prodiamine 65 WDG (professional grade, 6-9 month control): Check price on Amazon
- Scotts Halts Crabgrass Preventer (retail, 3-4 month control): Check price on Amazon
First Mow of the Season
Set your blade at 3 inches for the first cut. Bag clippings this one time to remove winter debris, dead leaf material, and any matted grass. After this initial mow, switch back to mulching. Sharpen your mower blade before the season starts. Dull blades tear grass tips, leaving brown edges that invite disease.
Soil Testing
If you did not test in fall, submit a soil sample now. Results take 2-3 weeks, and you want that data before your April fertilizer application. Contact your local county extension office for a $10-20 test. Most cool-season lawns perform best at pH 6.0-7.0. Without a test, you are guessing.
Warm-Season Lawns (Zones 7-10)
Bermuda and zoysia are still dormant across most of Zones 7-8 in March. The single most important rule: do NOT fertilize dormant warm-season grass. Fertilizer applied to dormant turf feeds weeds, not your lawn, and the unused nitrogen leaches away.
In Zones 9-10, warm-season grasses may already be approaching green-up. Apply pre-emergent now, because the soil warms earlier in the deep South. St. Augustine and bermuda lawns in south Florida and along the Gulf Coast should already have pre-emergent down by early March.
Monitor for green-up across all warm-season zones. Bermuda greens up when soil hits 65°F consistently. Until you see active growth, your job is patience and pre-emergent timing.
Common Mistake: Applying Pre-Emergent Too Late
Once you see crabgrass, it is too late for prevention. Pre-emergent only works on seeds that have not yet sprouted. Curative treatment with post-emergent herbicides is harder, more expensive, and less effective. One visible crabgrass plant can produce 150,000 seeds. Set a calendar reminder for early March and track soil temps weekly.
What Should You Do in April?
April is fertilization month. Cool-season grasses get their first real feeding. Warm-season grasses break dormancy and start the first mow cycle.
Cool-Season Lawns
First Fertilizer Application
April brings the first real feeding for cool-season turf. Apply 0.75-1 lb of nitrogen per 1,000 sq ft using a slow-release product. This is not the time for heavy nitrogen. Research from North Carolina State University turfgrass program shows fall-dominated fertilization programs produce 23% denser turf than spring-heavy programs. Spring fertilizer supports steady growth. Fall fertilizer builds the root system.
Recommended Fertilizers
- Scotts Turf Builder (32-0-4, slow-release): Check price on Amazon
- Milorganite (6-4-0, organic, slow-release): Check price on Amazon
Weekly Mowing Begins
Cool-season grasses enter active growth in April. Begin mowing weekly at 3-3.5 inches. Never remove more than one-third of the grass blade in a single cut. Mulch clippings, which return about 25% of your lawn's nitrogen needs back to the soil for free.
Irrigation Check
If April rainfall drops below 1 inch per week, start supplemental watering. Water deeply and infrequently, targeting 1 inch total per week from rain and irrigation combined. Early morning watering (before 8 AM) reduces disease risk.
Broadleaf Weed Monitoring
Dandelions, clover, and chickweed start emerging in April. If populations are small, spot-treat rather than broadcasting herbicide across the entire lawn. Wait until weeds are actively growing and temperatures stay between 50-85°F for best results.
Warm-Season Lawns
First Fertilizer After Green-Up
Fertilize warm-season grass only when it reaches 50% green or more. Applying fertilizer to grass that is still mostly dormant wastes product and promotes weed growth in thin areas. Scotts Turf Builder Southern (32-0-10) is formulated for bermuda, zoysia, St. Augustine, and centipede.
First Mow by Grass Type
| Grass Type | Mowing Height | Frequency |
|---|---|---|
| Bermuda | 1.5-2 inches | Weekly (increasing to 2x/week by May) |
| Zoysia | 1-2 inches | Weekly |
| St. Augustine | 3-4 inches | Every 7-10 days |
| Centipede | 1.5-2 inches | As needed (slow grower) |
Weed Monitoring in Thin Spots
Warm-season lawns coming out of dormancy often have thin areas where weeds try to establish. Monitor these spots closely. A thick, healthy warm-season lawn is the best weed defense, but it takes a few weeks of active growth to fill in.
Common Mistake: Over-Fertilizing in Spring
Cool-season lawns get their heaviest feeding in fall, not spring. Heavy spring nitrogen pushes rapid leaf growth at the expense of root development. That top-heavy grass looks great in May but collapses under summer heat stress. Stick to 0.75-1 lb N per 1,000 sq ft in spring and save the 1-1.5 lb applications for September and October.
What Should You Do in May?
May is grub prevention month and the last window for spring weed control. Bermuda enters peak growth mode. Cool-season grasses need mowing height raised.
Cool-Season Lawns
Grub Prevention
Japanese beetle and June bug grubs feed on grass roots from July through September. Preventive insecticide applied in May stops them before damage starts. You will not see grub damage until August, when skunks and raccoons start digging up your lawn to eat them. By that point, the grubs have been chewing roots for six weeks.
Prevention in May costs about $20-30 for a typical lawn. Recovery in September, including new seed, topsoil, and your time, easily runs $200 or more.
Recommended Products
- Scotts GrubEx (chlorantraniliprole, season-long control): Check price on Amazon
Last Chance for Broadleaf Weed Control
May is your final opportunity to treat broadleaf weeds before summer heat makes herbicide applications risky. Dandelions, clover, and plantain respond well to treatment when actively growing and air temperatures stay below 85°F. Once summer heat arrives, herbicide stress combined with heat stress can damage your lawn.
- Ortho Weed B Gon (2,4-D + triclopyr, ready-to-spray): Check price on Amazon
- Drive XLR8 (quinclorac, targets crabgrass + broadleafs): Check price on Amazon
Raise Mowing Height
As temperatures climb, begin raising your cool-season mowing height toward 3.5-4 inches. Taller grass shades the soil surface, reducing soil temperature and suppressing weed seed germination. According to Michigan State University Extension, proper mowing height is one of the top three factors for lawn density and weed prevention.
Fungal Disease Monitoring
Brown patch and dollar spot thrive in humid conditions when nighttime temperatures exceed 65°F. Watch for circular brown or tan patches in your lawn, especially in areas with poor air circulation. Reducing evening watering and improving drainage are your first defenses before reaching for fungicide.
Warm-Season Lawns
Peak Growth Fertilization
Bermuda enters peak growth mode in May. Feed every 4-6 weeks through the growing season with 0.5-1 lb N per 1,000 sq ft per application. Bermuda can handle more nitrogen than most grasses, but split applications work better than one heavy dose.
Deep Watering
Target 1-1.25 inches of water per week as temperatures rise. Water deeply two to three times per week rather than daily light sprinkles. Deep watering pushes roots down. Shallow watering keeps roots near the surface, where they bake in summer heat.
Pest Monitoring
St. Augustine lawns need weekly chinch bug inspections starting in May. These tiny insects suck plant juices and cause irregular yellow-brown patches that spread outward. Armyworms also become active in late spring across the Southeast. Check your lawn in early evening when armyworms start feeding.
Mowing Frequency
Bermuda in peak growth may require mowing twice per week to maintain the one-third rule. Letting bermuda get too tall before cutting creates scalping, thatch buildup, and brown stubble. Zoysia, St. Augustine, and centipede typically stay on a weekly schedule.
Common Mistake: Skipping Grub Prevention
Grub damage is invisible until it is severe. The larvae feed underground on roots through summer. The first visible sign is usually patches of turf that peel up like carpet in late August or September. By then, recovery requires reseeding or sodding. A single preventive application in May eliminates this risk almost entirely.
Which Spring Tasks Apply to Your Grass Type?
Every grass type has different timing for spring tasks. This table pulls from verified monthly data for all eight common lawn grasses across their typical growing zones.
| Grass Type | March | April | May |
|---|---|---|---|
| Kentucky Bluegrass | Pre-emergent when forsythia blooms | Fertilize, begin regular mowing | Fertilize, mow weekly, monitor for grubs |
| Tall Fescue | Pre-emergent (if not overseeding), first mow | Light fertilizer, regular mowing begins | Mow at 3.5-4", monitor weeds |
| Perennial Ryegrass | Pre-emergent, first mow if growing | Fertilize, regular mowing | Mow regularly, monitor weeds, begin irrigation |
| Fine Fescue | Pre-emergent if weed pressure is high | Light fertilizer, mow at 3-3.5" | Mow as needed (slow grower) |
| Bermuda | Apply pre-emergent, monitor dormancy | First fertilizer when 50%+ green, begin mowing | Fertilize, deep water, mow 2x/week |
| Zoysia | Apply pre-emergent, watch for green-up | First fertilizer after green-up, begin mowing | Mow regularly, monitor weeds, start irrigation |
| St. Augustine | Apply pre-emergent, watch for green-up | First fertilizer, begin mowing at 3-3.5" | Monitor for chinch bugs, start deep watering |
| Centipede | Apply pre-emergent, watch for green-up | Begin mowing at 1.5-2", do NOT fertilize yet | First light fertilizer after full green-up |
Centipede is the outlier worth highlighting. It is extremely sensitive to over-fertilization. According to University of Georgia Extension, centipede lawns require only 1-2 lbs of nitrogen per 1,000 sq ft per year, compared to 4-6 lbs for bermuda. More nitrogen on centipede actually causes decline, a condition called "centipede decline." Wait for full green-up, usually May, before that first light feeding.
What Products Do You Need for Spring?
Here is a consolidated shopping list of every product mentioned in this guide, with pricing and purchase links for quick reference.
Pre-Emergent Herbicides
Fertilizers
Weed Control
Pest Prevention
Equipment
Total Spring Budget (5,000 sq ft Lawn)
| Category | Product | Estimated Cost |
|---|---|---|
| Pre-emergent | Prodiamine or Scotts Halts | $25-30 |
| Spring fertilizer | Scotts Turf Builder or Milorganite | $25-33 |
| Weed control | Ortho Weed B Gon | $15 |
| Grub prevention | Scotts GrubEx | $28 |
| Spreader (one-time) | Scotts EdgeGuard DLX | $45 |
| Total (first year) | $138-151 | |
| Total (returning) | $93-106 |
For context, a single professional lawn care visit typically costs $60-100. A full spring program from a service runs $200-400. DIY saves real money if you are willing to invest the time, and these products are straightforward to apply with a broadcast spreader. Check out our lawn mower reviews and product reviews hub for more equipment recommendations.
Frequently Asked Questions About Spring Lawn Care
When should I start spring lawn care?
Start when soil temperatures reach 55°F for 3-5 consecutive days. In the South (Zones 8-10), that's often late February. In the Midwest and Northeast (Zones 5-7), it's late March to mid-April. Use a soil thermometer at 2-4 inch depth for accuracy, or watch for forsythia blooms as a natural signal.
Can I seed and apply pre-emergent at the same time?
No. Pre-emergent herbicides kill all germinating seeds, including grass seed. If you need to overseed and prevent crabgrass, use mesotrione (Tenacity), which is the only pre-emergent safe for use at seeding. Otherwise, wait 8-16 weeks after standard pre-emergent before seeding, or plan to overseed in fall instead.
How do I know when soil temperature is 55°F?
Insert a soil thermometer 2-4 inches deep in a shaded area of your lawn. Check in the morning for 3-5 consecutive days. Many local university extensions publish daily soil temperature maps online. You can also watch for forsythia blooms, which reliably coincide with 55°F soil temps in most regions.
What's the best spring fertilizer?
For cool-season lawns, a slow-release nitrogen fertilizer at 0.75-1 lb N per 1,000 sq ft works well. Scotts Turf Builder (32-0-4) and Milorganite (6-4-0) are both solid options. For warm-season lawns in the South, Scotts Turf Builder Southern (32-0-10) is formulated for bermuda, zoysia, and St. Augustine.
Should I dethatch in spring?
Only if thatch exceeds 0.5 inches thick. For cool-season grasses, early spring or early fall works. For warm-season grasses, dethatch after full green-up in late spring. Light dethatching is fine, but aggressive power raking in early spring can damage grass that hasn't fully recovered from winter dormancy.
When should I start mowing?
Mow when grass reaches about one-third taller than your target height. For cool-season grasses, this usually means the first mow in late March or April at 3 inches. For warm-season grasses, wait until active green-up, typically April in Zones 7-8 and March in Zones 9-10. Sharpen your blade before the first cut.
Is spring or fall better for overseeding?
Fall is better for cool-season grasses in almost every situation. Fall-seeded grass faces less weed competition, lower heat stress, and has an entire cool growing season to establish before summer. Spring seeding is acceptable for warm-season grasses like bermuda and zoysia, which thrive in heat.
How Can You Skip the Guesswork?
You just read a comprehensive guide to spring lawn care covering every month, every grass type, and every product worth buying.
TurfTracker takes all of this and turns it into a personalized weekly plan based on YOUR grass type, YOUR zone, and YOUR local weather. No more checking soil temperatures with a thermometer every morning. No more calculating fertilizer rates by hand. No more forgetting to apply grub prevention until you find skunks digging up your yard in August.
The app monitors soil temperature data for your zip code and sends you a push notification when it is time to apply pre-emergent. It calculates exactly how many pounds of product you need for your lawn size. It adjusts mowing and watering recommendations based on your local 7-day forecast.
About the Author
Anton Schwarz has spent over 15 years perfecting turfgrass management across three climate zones, with extensive experience in both warm-season and cool-season grasses. B.S. in Turfgrass Science from the University of Georgia. His approach prioritizes soil health, proper timing, and science-backed methods over quick fixes.
Every recommendation in this guide comes from field-tested experience and verified university research. Learn more about Anton and the Lawn Care Guides team.