Characteristics of Common Natural Fertilizers
| Material | Content as % weight* | Release rate | Use | ||||
|---|---|---|---|---|---|---|---|
| N | P2O5 | K2O | Fast | Med | Slow | ||
| Bloodmeal | 13 | X | Midseason sidedress; or full season supply | ||||
| Broiler manure pellets | 3-4 | X | X | Full season supply; also contains some K | |||
| Corn gluten | 9 | X | X | Full season; use only on established plants | |||
| Feather meal | 12 | X | X | Full season supply | |||
| Fish emulsion | 4 | 3 | X | Midseason sidedress or supplement | |||
| Fish meal | 9 | 6 | X | X | Midseason, or full season of both N&P | ||
| Crab meal | 6 | 3 | X | Full season supply; contains 25% lime | |||
| Soybean meal | 7 | 2 | X | X | Midseason sidedress; or full season supply | ||
| Poultry manure (fresh) | ≤3 | ≤3 | X | Full season N supply; fast correction of P; use if lime is needed | |||
| Bone meal/char | 15 | X | X | Fast correction of P | |||
| Rock phosphate | 30 | X | Long-term P supply (3% is available fast) | ||||
| Alfalfa meal | 2.5 | 2 | X | X | Full season supply | ||
| Cottonseed meal | 7 | 2 | X | X | Full season supply | ||
| Cow manure (fresh) | ≤1 | ≤1 | X | X | Full season N supply; fast correction of K | ||
| Potassium sulfate | 50 | X | Fast correction of K; contains 18% sulfur | ||||
| Wood ash (dry) | 5 | X | Fast correction of K if lime is also needed | ||||
| Sul-Po-Mag | 22 | X | X | Full season supply; contains 23% sulfur and 11% magnesium | |||
* Always check the label to determine the guaranteed analysis of packaged consumer products.
Natural fertilizer information from http://anlab.umesci.maine.edu/soillab_files/under/orgnutgd.pdf.
From the GardenPro Answer Book; revised and updated by Lois Berg Stack, Ornamental Horticulture Specialist, University of Maine Cooperative Extension.