Ideally you would run some basic soil tests and fertilize based on the results of the tests. They would tell you how much (and if) you need to fertilize or if your pH needs to be adjusted. In general, one would use a multipurpose granular fertilizer such as 10-10-10 or 5-10-5 according to the fertilizer's label instructions and/or some compost. Some shrubs do need a particularly acid soil, and you should check with your local nursery for specific plant recommendations.



I would like to use an organic fertilizer for my plants. What do you suggest?
Adding compost is one of the very best things you can do to improve your soil. Compost improves soil structure, making it more workable; 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 include: Nitrogen: alfalfa meal, blood meal, coffee grounds, cottonseed meal, fish emulsion, seabird guano. Phosphorous: bone meal, rock phosphate. Potassium: greensand, seaweed, kelp. Mix your own with the above materials to make a custom blend specifically for what you're growing. 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.