Why then
Warm-season lawns feed during their growth engine: from full green-up (3–6 weeks after last frost) through late summer, roughly monthly at modest rates. The critical *stop* date matters as much as the start — nitrogen within 6–8 weeks of first frost pushes tender growth that winter kills.
Frequently asked questions
When should I fertilize my lawn in Hawaii?
Across Hawaii's featured cities the window runs Mar 3 – Mar 24. Your own town can sit at either end of that range — use the city table on this page or the ZIP lookup for your exact dates.
Why do the dates vary within Hawaii?
Because climate does. The dates here are calculated separately for each city from its own NOAA 1991–2020 frost records, and elevation, latitude, and terrain spread them across Hawaii — the same task can be a week or two apart between towns. That local spread is exactly what generic national advice misses.
What if I miss the window?
Better to skip than to force it. Doing this job in the wrong season stresses the lawn more than not doing it at all — set a reminder for the next window.