All gardens benefit from regular additions of soil amendments. Apply amendments individually or in combination each season and whenever you plant. Spread compost, manure, and peat three inches deep on top of soil and work in to the top three to six inches, apply 1/2 inch or less of sand, greensand, and vermiculite, perlite, or gypsum, and work into the top eight inches of soil.
The following materials help improve soil's fertility and its capacity to hold and drain moisture:
Decomposed leaves, grass clippings, plant-based kitchen scraps, and other organic materials. A well-balanced, slow-release, nutrient- and humus-rich amendment. Lightens heavy soils; enriches poor soil.
Powdered mineral that loosens heavy and clay soil; improves drainage.
Plants need a balance of nutrients for healthy growth. Fertilizers, or complete plant foods, contain all of the basic nutrients: nitrogen, phosphorus, and potassium. These nutrients are listed on packaged plant foods in percentages of N-P-K. The following organic materials, when added to soil, supply specific nutrients needed by plants.
Nitrogen (N) Sources for Leaf and Stem Growth
- Alfalfa meal
- Blood meal
- Composted manure
- Cottonseed meal
- Feather meal
- Fish meal or emulsion
- Mushroom compost
- Rice hulls
Phosphorus (P) Sources for Root Growth, Flower Color, and Disease Resistance
- Bat guano
- Rock phosphate
Potassium (K) Sources for Fruit and Seed Production
- Dolomite lime
- Kelp meal
- Oyster-shell lime
- Rock dust
- Wood ashes