13-13-13 Fertilizer
Balanced / all-purpose13-13-13 is 13% nitrogen, 13% phosphate and 13% potash by weight. To apply 1 lb of nitrogen per 1,000 sq ft, spread 7.69 lbs of product per 1,000 sq ft; a 50-lb bag covers about 6,500 sq ft at that rate.
What 13-13-13 Means
Nitrogen (N)
13%
6.5 lb per bag
Green color and growth
Phosphate (P₂O₅)
13%
6.5 lb per bag
Root growth, new seedlings
Potash (K₂O)
13%
6.5 lb per bag
Stress, drought and cold tolerance
Pounds shown are per 50-lb bag. The N:P:K ratio simplifies to 1:1:1. The remainder of the bag is carrier, filler, and secondary nutrients.
How Much 13-13-13 to Apply
Lawn feeding is measured in pounds of nutrient per 1,000 sq ft. Here's how much product hits each common target.
| Target | Product / 1,000 sq ft | Per acre | 50-lb bag covers | Delivers (N-P-K lb) |
|---|---|---|---|---|
| 0.25 lb N | 1.92 lb | 83.8 lb | 26,000 sq ft | 0.25-0.25-0.25 |
| 0.5 lb N | 3.85 lb | 168 lb | 13,000 sq ft | 0.5-0.5-0.5 |
| 0.75 lb N | 5.77 lb | 251 lb | 8,667 sq ft | 0.75-0.75-0.75 |
| 1 lb N | 7.69 lb | 335 lb | 6,500 sq ft | 1-1-1 |
What It's For
A balanced triple-13, common at farm stores. Like 10-10-10, it's an all-purpose blend rather than a lawn-specific one.
When to Use It
At seeding, or on lawns a soil test shows need all three nutrients.
Before You Spread It
- Usually all quick-release nitrogen. Keep rates modest and water it in.
- Several states restrict phosphorus on established lawns unless a soil test shows a need or you're seeding. Check your state's rules before using it as a routine feed.
13-13-13 Calculator
Enter your lawn size to get the total amount, or change the analysis to check a different bag.
Spread 7.69 lb per 1,000 sq ft, 38.46 lb for 5,000 sq ft (0.77 bags).
Delivers 1 lb N, 1 lb P₂O₅ and 1 lb K₂O per 1,000 sq ft. Never exceed the label rate.
Common Questions
How much 13-13-13 per 1,000 sq ft?
To deliver 1 lb of nitrogen per 1,000 sq ft, apply 7.69 lbs of 13-13-13 per 1,000 sq ft, or about 335 lbs per acre. Many applications use half that or less, and the product label rate always comes first.
What is 13-13-13 fertilizer used for?
A balanced triple-13, common at farm stores. Like 10-10-10, it's an all-purpose blend rather than a lawn-specific one.
When should I apply 13-13-13?
At seeding, or on lawns a soil test shows need all three nutrients.
What do the numbers 13-13-13 mean?
They're the percentages by weight of nitrogen (N), phosphate (P₂O₅) and potash (K₂O). A 50-lb bag of 13-13-13 contains 6.5 lbs of nitrogen, 6.5 lbs of phosphate and 6.5 lbs of potash; the rest is carrier and other ingredients.
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