Planting well is the most important gardening task: Planting establishes roots, and every leaf, stem, and flower relies on the water, nutrients, and support that roots provide. Begin by testing your soil for nutrient content, pH, organic (humus) content, and texture. For information on soil testing in your area, contact your local cooperative extension office, listed in the phone book under government offices.
Test soil close to planting time in spring or fall to ensure an accurate reading, but leave enough time to add any recommended soil amendments. Ideally, for spring planting, prepare the soil the previous fall, and for fall planting, prepare it in early summer. Use your soil-test results as a guide for preparing planting beds and selecting trees and shrubs.
For vegetables, annuals, perennials, and roses -- plants that tend to be compact-rooted but heavy-blooming and heavy-cropping -- first prepare a bed: Clear an area of weeds and debris. Using a spade or fork, turn the soil to a depth of 12 to 14 inches and incorporate a 3- to 4-inch layer of compost (or well-rotted manure and any amendments recommended by your soil test) into the top 10 to 12 inches of soil. Rake the soil so it is loose, airy, and flat.
For trees and shrubs with expansive root systems that need to spread freely through the soil, choose species adapted to your garden soil and alter the existing soil only minimally before planting.
Always water well immediately after planting, and give new plants at least an inch of water weekly during dry spells through the rest of the first growing season.