Mushroom compost is a good fertilizer for vegetable garden soil. Mushroom growers mix chicken manure, gypsum, straw, nitrate and other organic materials. The concentrated nutrients that remain after use in growing mushrooms are also high in salts, so you must mix it with planting soil before putting it in your vegetable bed.
Buy mushroom compost from a garden center or nursery.
Buy organic planting soil from a garden center or nursery. You can mix the compost with soil in your vegetable garden rather than purchasing new soil.
Mix the soil and mushroom compost using 2 parts soil to 1 part mushroom compost.
In the fall, put the organic soil and mushroom compost in your vegetable garden so it can age over the winter.