Choose Container Roses
At this point in the season, container-grown roses will be more successful than packaged dormant roses. A thriving potted rose makes a wonderful Mother's Day present. When planting grafted roses into the garden, set the graft 1 to 2 inches below the soil line. Roses planted this deep will more successfully overwinter. Whether you use organic or chemical pest controls, begin a regular spray schedule to keep insects and diseases at bay. As the flowers bloom and fade, clip them off regularly to encourage rebloom. Do not prune once-blooming roses if you want hips to develop.
Prune Flowering Shrubs
Forsythia, deutzia, spirea, lilac, and other spring-blooming shrubs can be pruned immediately after flowering, either to shape or to remove old or undesirable growth. Try to cut at least a few of the oldest branches back to the ground each year. On lilacs, remove only the faded flower heads, leaving the two buds at the base, unless it's time to remove older or undesirable stems.
Plant Summer Bulbs
Summer bulbs, such as caladiums, gladiolus, cannas, dahlias, montbretias, tuberous begonias, and tuberoses, can be planted directly into the garden now. They will not be up for several weeks, so if there is a late frost, they will not be harmed. Garden centers usually have these available, both dormant and as started plants. The potted, growing plants are an easy way to begin if you haven't grown them before. If you're using plants, wait a few more weeks until after the frost danger is past. With tall dahlias, set the stakes into the ground before backfilling with soil so the stake doesn't skewer the tubers.
Sow and Thin
Continue planting carrots and radishes together in the same row. By the time the carrots are ready for thinning, the radishes are ready for pulling. Thin out beets and lettuce, leaving several inches between plants. The thinnings can be used in salads, stir-fries, or soups. The first planting of green beans can be made now; plan on sowing seeds of bush beans every two weeks or so for continuous production, as they produce and die. In contrast, pole beans produce over a long season. Set out early tomato plants, but have protection ready in case of frosts.
Support Your Perennials
Many perennials make a much better appearance in the garden if they are supported. Garden centers, discount stores, and mail-order catalogs offer a variety of stakes, rings, and cages. Whichever you choose, install them immediately if not sooner. Plants that are allowed to grow naturally through the supports look much better than if they are crammed into the support once they are already flopping. Some of the plants that benefit from support include yarrow, trycyrtis, delphiniums, joe-pye weed, asters, tall-growing sedums, and peonies.