
Below is a brief listing of the value of most organic fertilizers that you can purchase. The value listed is a close value for the product. This is what my bag of fertilizer said. Every manufacturer guarantees an analysis which may differ. Also different products are processed differently which can be reflected in the guaranteed analysis.
Fertilizer | N | P | K | Details |
Alfalfa Meal | 8 | 1 | 2 | You can use 6 lbs. per 100 sq. ft. It is fast-acting and must be renewed each year. |
Blood Meal | 12 | 1 | 1 | You can use 4 lbs. per 100 sq. ft. It is fast-acting and can burn the roots if you use too much. |
Bone Meal | 3 | 20 | 0 | You can use 3 lbs. per 100 sq. ft. It is cheap and an excellent source of phosphorus which is good for bulbs, fruiting plants and flowers. |
Cottonseed Meal | 7 | 2 | 2 | You can use 5 lbs. per 100 sq. ft. It is an excellent source of Nitrogen and other nutrients. Last 6 months to year depending on how well it is ground. |
Granite (ground) | 0 | 0 | 4 | You can use 8 lbs. per 100 sq. ft. Very long acting, last up to 10 years. Has several trace minerals. |
Green Sand | 0 | 0 | 7 | You can use 10 lbs. per 100 sq. ft. Long acting, 6-7 years. An Excellent source of over 20 trace minerals. One of my favorites! |
Guano | ? | ? | ? | Guano is bird or bat droppings. Strength varies. Never use more than 5 lbs. per 100 sq. ft. |
Lime dolomite | You can use 1-10 lbs. per 100 sq. ft. 46% Calcium Carbonate, 38% Magnesium Carbonate. Use only if your soil has a low pH. Very Alkaline. | |||
Kelp | You can use 1 lbs. per 100 sq. ft. Awesome source of over 70 trace minerals. This is seaweed mined from the sea. Kelp extracts also make an excellent Foliar Spray. | |||
Magnesium Sulfate | 10% Magnesium and 6% Sulfate Sulfur. You can use 6 lbs. per 100 sq. ft. | |||
Rock Phosphate | 0 | 33 | 0 | You can use 6 lbs. per 100 sq. ft. It is very slow acting and the 33% is release over 3-5 years. Only needs to be applied once every 3 years. |
Sul-Po-Mag | 0 | 0 | 22 | 11% Magnesium and 22% Sulfur. Best to have a soil test first on this one. |
Wood Ash | 0 | 0 | 5 | You can use 1 lb. per 100 sq. ft. This is fast acting and is very alkaline. Be careful not to apply if your pH is above 6.5. |
Worm Castings | 1 | 1 | 1 | You can use 2 cubic ft. per 100 sq. ft. This is a great soil amendment that I use in all containers. |