Mulch Now or Forever Hoe Your Weeds
Apply mulches now, while the soil is still damp, to help retain moisture and to keep weed seeds from germinating. A layer of organic mulch 2 to 3 inches deep is usually sufficient to discourage even the most persistent weed seeds.
Keep Container Plants Happy
Container-grown vegetables and flowers can dry out quickly, especially on a concrete patio in full sun. Daily watering may be necessary as the season progresses. To check for moisture, feel the soil in containers at least once a day. Water when the soil is dry down to a few inches. Apply water until it runs out of the drainage holes. Every two to three weeks, immerse each container in a larger container of water to force out air pockets and thoroughly moisten the root mass.
Prune rhododendrons immediately after flowering. Snap off old flower clusters (trusses) once they are partially dry. Remove them carefully so newly developing buds beneath the trusses aren't damaged. They will provide next year's blooms.
Harden Off Tender Seedlings
Begin hardening off tender vegetables, herbs, perennials, and annual flowers that you've started indoors. Start by placing them in a shaded, sheltered location for the day and bringing them in at night. Every few days, select a sunnier, windier spot until the end of the last week of May, when it is finally safe to plant most things outdoors.
Plant Summer-Flowering Bulbs
Cannas, caladiums, and tuberous begonia bulbs can be planted now. Choose a well-drained and partially shaded area, and set the tubers in the ground so they are barely covered. Place them 18 to 24 inches apart to allow plenty of space for growth and good air circulation. Water in the morning or early afternoon to give the foliage time to dry before nightfall, and you'll reduce the chances of disease.