Cool-season grass
How to fertilize Kentucky bluegrass
A cool-season grass that does most of its growing in spring and fall. Its fall feedings matter most. Here is how much it needs, when to feed it, and a calculator already set up for it.
Kentucky bluegrass at a glance
- Nitrogen a year1–4 lbper 1,000 sq ft
- Main feedingsSep & Novfall matters most
- Per feeding1.0 lb Nusual band 0.5–1 lb
- Feedings a year1–4at 1.0 lb each
Feeding calendar
When to feed Kentucky bluegrass
Cool-season grass
1–4 lb of nitrogen per 1,000 sq ft a year
At 1.00 lb a feeding, that is about 1–4 feedings a year.
Main feedings: September and November. Light or regional feedings: February, April and June.
Fall is the main season: feed in September and again around November while the grass is still green. Northern schedules add light feedings in late April and early June; the transition zone feeds in February instead. Skip feeding in summer heat. Low-care lawns need 1–2 lb a year, most lawns 2–3, and high-care lawns 3–4.
Typical ranges from university extension guides. Your state or county guide wins. See the sources.
Calculator
How much to spread on your Kentucky bluegrass
It starts at 1.0 lb of nitrogen per 1,000 sq ft on a 5,000 sq ft lawn. Change the numbers to match your lawn and your bag.
Worked examples
One feeding on 5,000 sq ft of Kentucky bluegrass
At 1.0 lb of nitrogen per 1,000 sq ft, with four common bag numbers.
| Bag numbers | Per 1,000 sq ft | For 5,000 sq ft |
|---|---|---|
| 29-0-4 | 3.4 lb | 17.2 lb |
| 16-4-8 | 6.3 lb | 31.3 lb |
| 10-10-10 | 10.0 lb | 50.0 lb |
| 46-0-0 | 2.2 lb | 10.9 lb |
Good to know
Feeding Kentucky bluegrass well
Fall is the main season: feed in September and again around November while the grass is still green. Northern schedules add light feedings in late April and early June; the transition zone feeds in February instead. Skip feeding in summer heat. Low-care lawns need 1–2 lb a year, most lawns 2–3, and high-care lawns 3–4.
Keep any single feeding to about 1 lb of quick-release nitrogen per 1,000 sq ft or less. Slow-release products may be labeled for more. Florida limits quick-release nitrogen to 0.7 lb per feeding.
The product label has the final say on rate and timing, and some states limit phosphorus or set dates when lawn fertilizer cannot go down. See how these numbers are worked out.
Questions
Kentucky bluegrass, answered
How much nitrogen does Kentucky bluegrass need a year?
Typical university guidance is 1–4 lb of nitrogen per 1,000 sq ft a year. Low-care lawns need 1–2 lb a year, most lawns 2–3, and high-care lawns 3–4.
When should I fertilize Kentucky bluegrass?
The main feedings fall in September and November. Light or regional feedings: February, April and June. For cool-season grass, the fall feedings matter most.
How much fertilizer do I need for 5,000 sq ft of Kentucky bluegrass?
At 1.0 lb of nitrogen per 1,000 sq ft, a 29-0-4 product needs 3.4 lb per 1,000 sq ft, so 17.2 lb for 5,000 sq ft in one feeding. Use the calculator on this page for your own lawn and bag.