by Bill Swantner, Bexar County Master Gardener It’s almost Spring garden time and there will be a lot of talk about compost, fertilizer, and mulch. What is the difference? Compost is a soil amendment. Good soil is 25% air, 25% water, 45% mineral (sand, silt, clay) and 5% organic material (decomposed plants & animals). The soil in Bexar County is …