Best Spring Lawn Fertilizers to Apply in March (2026)
March is when your lawn wakes up. The right fertilizer applied at the right time sets up thick, green growth for the entire season. Too early and you waste it. Too late and weeds beat you.
Here’s when and what to apply.
When to Fertilize in Spring
- Cool-season grasses (fescue, bluegrass, rye): Apply when soil temps hit 55°F, usually March–April
- Warm-season grasses (bermuda, zoysia, St. Augustine): Wait until soil hits 65°F, usually April–May
- Check soil temp with a $10 soil thermometer — don’t guess
Best Overall: Scotts Turf Builder Lawn Food
The classic. 32-0-4 NPK gives a strong nitrogen boost without excess phosphorus. Feeds up to 15,000 sq ft per bag. Won’t burn when applied correctly.
Why it’s great:
- 32-0-4 NPK — high nitrogen for green-up
- Feeds for up to 2 months
- All grass types
- Pairs with any Scotts spreader
Best Organic: Milorganite 0636
Milorganite is slow-release, organic, and nearly impossible to over-apply. Made from heat-dried microbes, it feeds your lawn and soil biology. No burn risk.
Why it’s great:
- 6-4-0 NPK — gentle, slow-release
- Organic and safe around kids/pets
- Feeds for 8-10 weeks
- Also adds iron for deep green color
Best Weed + Feed Combo: Scotts Turf Builder Weed & Feed
Kill two birds with one stone. Feeds the lawn while killing dandelions, clover, and other broadleaf weeds. Apply when weeds are actively growing and temps are between 60-90°F.
Why it’s great:
- Fertilizes + kills 50+ weed types
- Covers 15,000 sq ft
- Apply with any broadcast spreader
- Results in 1-2 weeks
Spring Fertilizer Schedule
- Early spring (March): Light feeding — half-rate application or slow-release organic
- Mid spring (April): Full application with pre-emergent if not already applied
- Late spring (May): Second feeding, especially warm-season grasses just waking up