Answer: I congratulate you for wanting to grow organically! Adding compost is one of the very best things you can do to improve your soil, so keep that up! If possible, it would be good to add more compost a few weeks before your spring planting. Or, if you can't make more compost over the winter, add your pile in the spring. Compost improves soil structure, making it more workable, it improves drainage in clay soil, improves moisture retention in sandy soil and provides food for beneficial organisms, like earthworms. However, the nutrients (nitrogen, phosphorous, potassium--the NPK listed on fertilizer containers) in compost can vary considerably. So until you build up an extremely healthy soil, it would be a good idea to add some nutrients. Organic fertilizers also vary in their NPK ratios, so try to create a fairly balanced mix, such as 10-10-10. Some organic fertilizers follow:
Nitrogen: alfalfa meal, blood meal, coffee grounds, cottonseed meal, fish emulsion, seabird guano.
Phosphorous: bone meal, rock phosphate
Potassium: greensand, seaweed, kelp.
In general terms, nitrogen produces lush
green growth, phosphorous helps strengthen stems and produce flowers, and potassium keeps the root system healthy. In reality, these elements work in conjunction with one another. If you're applying fertilizer to tomato plants, for example, you're not as interested in the plant developing leaves as you are in it flowers and fruit, so you'd use a formulation lower in nitrogen and higher in phosphorous and potassium, such as a 5-10-10. Since phosphorous doesn't move as readily through the soil as does nitrogen, it's a good idea to mix a small amount (follow package instructions) into the hole before transplanting, or to mix it into the soil before sowing seeds. Add the fertilizer before planting, and then see how the plants thrive. You can add a sidedressing of fertilizer mid season if the plants look like they need it. I think you're on the right track--feel free to write with other questions!
Q&A Library Searching Tips