• Camellias. Sunset climate zones 4-7, 17: Nurseries are full of flowering C. japonica varieties in 1-, 2-, and 5-gallon containers. These dependable bloomers bring lively color to areas that receive light to medium shade. In mild-summer regions, they can also take full sun.
• Cool-season crops. Zones 4-7, 17: A variety of vegetables grows well in cool soil and chilly weather. Look for seedlings at nurseries, which are often organized on sales tables by plant type and family group: beets, spinach, and Swiss chard; cabbage and its relations (broccoli, brussels sprouts, Chinese cabbages, cauliflower, kale, kohlrabi, mustard, and radishes); butter, leaf, and romaine lettuces; onion family (Chinese and regular chives, elephant garlic, soft- and hard-neck garlic, leeks, onions, and shallots); bush and pole peas; and potatoes. You can also plant bare-root asparagus, horseradish, and rhubarb, but do it early in the month.
• Lawns. Grass starts growing vigorously in the Northwest this month. Take advantage of it by laying sod (grass sold in mats like carpet) or planting seed. To prepare the soil, till the top 6 to 8 inches, pick out roots and rocks, add compost, and till again. Level and compress the soil with a roller, lay the sod or rake in seed, and roll again. If rain doesn't come, water frequently to keep the top layer of soil moist so seeds germinate or sod roots get established. Cut back slightly once grass is growing strongly. To patch worn lawns, just rough up bare areas with a rake, scatter seed, cover with a thin layer of sifted compost, and water.
• Warm-season crops. Sow basil, cucumbers, eggplant, melons, peppers, and tomatoes now, then transplant them into the garden in May.
• Feed lawns. Zones 4-7: Supercharge lawn growth by applying ½ to 1 pound nitrogen per 1,000 square feet. You can't go wrong with a fertilizer formulated in a 3-1-2 N-P-K ratio (3 parts nitrogen, 1 part phosphorus, 2 parts potassium).
• Propagate perennials. Dig up summer- and fall-flowering perennials, such as asters, chrysanthemums, and Shasta daisies, then cut or pull apart root masses and replant individual divisions. It's also a good time to transplant catmint seedlings. Zones 1-3: Divide plants in April. All zones: Wait until autumn to divide spring-flowering perennials, such as primroses.
• Prune clematis. Zones 4-7: Cut back summer- and fall-flowering clematis to the strongest stems, then scratch in fertilizer around the base of the plant. Zones 1-3: Prune after danger of hard frost is past. All zones: Wait to cut back spring-flowering varieties until right after bloom.