Characteristics of Common Natural Fertilizers
|Material||Content as % weight*||Release rate||Use|
|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.