Prepare for Frost
The last frost date is based on the average of past years, and for most of the upper south that date is May 10. Although April temperatures have been warmer than normal for much of the region this year, unexpected cold spells can't be ruled out, both before and after the frost date. Be prepared by having materials on hand to quickly cover plants, such as newspapers, cardboard boxes, old bed sheets, frost protection fabric, or other light cloth, as well as purchased plastic tents and so forth. Be sure to remove the covers in the morning.
Prune Spring-Flowering Trees and Shrubs
As soon as early-flowering trees and shrubs -- such as forsythia, crab apples, and lilacs -- bloom, prune to maintain size and shape. For shrubs, remove about a third of the oldest stems to ground level. This helps to encourage new, healthy growth. Cut out or break off the spent flower heads from rhododendrons and azaleas. For trees, remove any suckers that arise from the base of the plant. Weed around the plants, fertilize, water, and apply fresh mulch.
Plant Tender Bulbs
Dahlias, gladiolas, tuberous begonias, cannas, callas, caladiums, tuberoses, and elephant's ears are just some of the tender bulbs that bring color and form to the garden. If not already started indoors in pots, these can be planted directly into the garden when frost danger is past. Be sure to know the light and drainage conditions that are best for each one. Plant gladiolas at two-week intervals until the first of July to provide cut flowers throughout the summer.
Although late summer is the best time to make major lawn renovations, small areas, such as bare spots, can be repaired now. Use a hard-tined garden rake to loosen the soil surface and sow lawn seed evenly over the area, using a high-quality seed mixture that's best for the amount of light and use. Tamp the seed lightly with the rake and water. Keep the area moist by covering with a light mulch of straw or lawn clippings.
Don't Dig Wet Soil
Most gardeners strive to improve their soil, so don't mess with a good thing by working in the garden when the soil is too wet. Digging in soil that is too wet destroys the soil structure, which means it will turn into a brick when dry. To determine if your soil is workable, pick up a handful and squeeze it. Open your hand and poke the ball. If it stays as a ball, the soil is too wet to work. If the soil forms a ball that breaks apart easily when you apply light pressure, it is workable.