Amend soil in early spring for continued plant grow, and in fall or at replanting for new flower and vegetable beds. Spring amendments encourage new growth and blooming, while fall amendments rejuvenate soil for new plants.
Add 2 to 3 inches of organic compost to the top 2 to 3 inches of natural soil around established plantings in spring. To rejuvenate old, unplanted soil, dig into the top 10 inches to loosen the foundation, and add 4 to 5 inches of organic compost.
Feed plants and soil with complete 5-10-5 or balanced 12-12-12 or 13-13-13 granular fertilizer. Follow manufacturer directions as to quantity, and mix the fertilizer into the top 4 inches of soil.
Water plants or soil after feedings to dissolve the fertilizer. Water plants with 2 to 3 inches of water, and empty plots for 30 minutes. Mulch the soil around plants or over empty plots with 2 inches of organic mulch to keep the soil moist and protected.