0-0-7 fertilizer is a pre-emergent herbicide and fertilizer blend with zero nitrogen, zero phosphorus, and seven percent potassium, designed to stop crabgrass and other weeds from germinating without stimulating leaf growth.
A lawn that looks good in spring starts with a decision made in early spring — and 0-0-7 is the tool for that job. It delivers a weed-preventing chemical barrier while feeding roots potassium, all without the nitrogen that pushes a surge of green growth you don’t want yet. One bag covers around 12,000 square feet when applied at the standard rate, and the protection lasts roughly three months with proper activation.
What Does The 0-0-7 Label Actually Mean?
Fertilizer labels list three numbers: nitrogen, phosphorus, and potassium — always in that order. A 0-0-7 bag contains zero percent nitrogen, zero percent phosphorus, and seven percent potassium by weight. The first two zeros are intentional: no nitrogen means the lawn won’t green up or grow faster, and no phosphorus means no root or flower stimulation. The seven percent potassium strengthens root systems and helps grass tolerate drought and disease stress without triggering top growth you’d have to mow.
How Does 0-0-7 Stop Weeds And Feed Roots?
The weed control comes from a pre-emergent herbicide mixed into the granular fertilizer — typically prodiamine at 0.37% or dithiopyr (Dimension). When applied and watered in, it forms a chemical barrier in the top inch of soil that blocks weed seeds from developing roots. Crabgrass seeds never sprout because the barrier intercepts them at germination.
The potassium component works separately from the herbicide. It moves into the soil and becomes available to grass roots over several weeks, supporting cell structure, water regulation, and stress tolerance. This is particularly valuable going into summer heat or winter dormancy when extra root strength matters more than top growth.
Application matters. Spread at roughly 3 pounds per 1,000 square feet using a rotary broadcast spreader, then water in with half an inch of rain or irrigation within 24 to 48 hours. Skip the watering step and the chemical barrier never activates — that’s the most common mistake homeowners make. Sweep any granules off driveways or sidewalks to avoid staining. Wear gloves; the granules can irritate skin.
When Should You Apply 0-0-7 Fertilizer?
Timing is everything because a pre-emergent only works before weed seeds germinate. The soil temperature needs to hit 50 to 55 degrees Fahrenheit for three consecutive days.
Spring window: In warm regions (transition zone and southern states), aim for early to mid-March. In cooler northern climates, mid to late April is the sweet spot. A natural sign is when forsythia shrubs bloom — that’s the same temperature trigger. For readers looking at specific product options and prices, our tested roundup of the best 0-0-7 fertilizers compares formulations, coverage, and value per bag.
Fall window: Late August through mid-September, when soil temperatures drop toward 70 degrees. This catches winter annual weeds like henbit and poa annua. On dormant warm-season grasses — Bermuda, Zoysia, Centipede — 0-0-7 is safe in winter and early spring because it carries no nitrogen that would force unwanted growth.
In long growing seasons, plan a reapplication every 8 to 10 weeks. A single application won’t cover the full season in regions where crabgrass germinates in waves.
Which Grasses Tolerate 0-0-7, And What Are The Limits?
Most common lawn grasses accept 0-0-7 without issue: tall fescue, Kentucky bluegrass, perennial ryegrass, Bermuda, Zoysia, St. Augustine, and Centipede. The zero-nitrogen formula makes it safe for use on dormant warm-season lawns that would be damaged by a traditional spring fertilizer.
The main restriction involves reseeding. If you use a prodiamine-based formulation like Lesco Stonewall, wait at least four months after application before overseeding — the barrier that stops crabgrass seeds will also stop grass seed from germinating. If you plan to seed in spring, choose a different product or skip the pre-emergent in that area.
FAQs
Can I use 0-0-7 on a new lawn?
No — 0-0-7 stops all seed germination, including grass seed. Wait until new grass is fully established through at least two mowings before applying a pre-emergent product like this.
Will 0-0-7 green up my lawn?
No. Because it contains zero nitrogen, 0-0-7 will not produce the dark green color that standard lawn fertilizers provide. Its job is weed prevention and root support, not cosmetic greening.
Do I need to water in 0-0-7 after spreading?
Yes. Watering in with about half an inch of water within 24 to 48 hours is essential to activate the herbicide barrier. Without moisture, the granules sit on the soil surface and the weeds germinate anyway.
References & Sources
- Clemson Cooperative Extension. “Just Say No to Pre-Emergent Herbicide and Fertilizer Combination Products” Explains why combination products like 0-0-7 work well only when timing matches both weed and grass cycles.
- The Home Depot. “LESCO 50 lb Crabgrass Control 0-0-7 Product Page” Confirms application rates, coverage, and active ingredient details for a commercially available formulation.