Type in the numbers from your soil test report — get a plain-english grade for each and the fixes in the right order.
How to read the brackets
pH: 6.0–7.0 happy · P: ~25+ ppm sufficient · K: ~100+ ppm sufficient · OM: 3%+
A soil test's magic is telling you what NOT to buy. "Low" means the lawn will visibly respond to that nutrient; "high" means the bag is a donation to the runoff. Most soil problems also rank: pH gates everything (acid soil locks nutrients away from grass no matter how much you add), then the deficient nutrient, then the long game of organic matter.
A worked example
pH 5.6, P at 40 ppm, K at 60 ppm, OM 2%: the order is lime first (the lime calculator doses it from this pH), then a potassium-forward fertilizer this fall (that's the bag's THIRD number — the fertilizer calculator handles the pounds), skip phosphorus entirely, and start mulching clippings and topdressing compost for the OM. Two products bought, one skipped, nothing wasted.
Test smart
Sample a dozen spots 4 inches deep, mix them in a clean bucket, and send one composite — one weird spot shouldn't set the whole lawn's diet. Retest every 2–3 years, same season each time. And nitrogen isn't on the report for a reason: it moves too fast in soil to test meaningfully, which is why N runs on the standard seasonal schedule regardless.
Frequently asked questions
How do I get a soil test?
Your state's extension service (search '[your state] extension soil test') runs them for $10–25: you mail a bag of soil, they mail back a report. Kits from the hardware store test pH decently but read nutrients crudely — the lab report is what this page is built to translate.
What do P and K numbers on a soil test mean?
Phosphorus (P) and potassium (K) available in your soil, usually in ppm. Labs bracket them as low/medium/high — low means the lawn will respond visibly to adding that nutrient; high means adding more is pure waste (and for P, runoff pollution). This is why soil-test-first beats bag-first shopping.
Why does my report say to add no phosphorus?
Most established lawns have plenty — clippings recycle it, and decades of old-school fertilizer banked it in the soil. That's also why most lawn fertilizers are now middle-number-zero (like 24-0-4) and several states restrict lawn phosphorus by law. Trust the test.
What is organic matter and what should it be?
The percentage of your soil that's decomposed living material — the sponge that holds water and feeds soil biology. 3–5% is a happy lawn; under 2% (common in builder-grade subsoil yards) explains a lawn that needs constant water and food. The fix is slow and cheap: mulched clippings, mulched leaves, and compost topdressing.