This table shows the qualities of various natural substances commonly used to fertilize organic vegetable gardens. The information is taken from Oregon State University Extension Service.
Fertilizer |
Nitrogen % |
Phosphorus |
Potassium |
When it is available to plants |
Time that it’s effective |
Bat Guano |
5.5-8 |
4-8.6 |
1.5 |
Medium to Fast |
|
Blood Meal |
12.5 |
1.5 |
0.6 |
Medium |
6-8 weeks |
Bone meal (steamed) |
.7-7 |
18-24 |
0 |
Slow to medium |
2-4 months |
Compost |
1.5-3.5 |
.5-1 |
1-2 |
Slow |
|
Cottenseed meal |
6-Apr |
2.5-3 |
1.6 |
Slow to medium |
4-6 months |
Feather meal |
15 |
0 |
0 |
Slow |
4-6 months |
Fish emulsion |
5 |
1 |
1 |
Fast |
2 weeks |
Fish meal – dry |
10 |
4-6 |
0 |
Medium |
4-6 months |
Kelp |
1 |
0.5 |
4-13 |
Slow |
4-6 months |
Mushroom compost |
.5-.8 |
40-55 |
.5-.8 |
Slow |
|
Phosphate, colloidal |
0 |
17-25 |
0 |
Slow |
3 years |
Phosphate, rock |
0 |
17-30 |
0 |
Very slow |
5+ years |
Seaweed |
0-2 |
0 |
.5-1 |
Fast |
|
Worm castings |
1.5 |
2.5 |
1.3 |