Northern California June checklist
What to do in your garden in June
• Plants for Dad Nurseries carry many plants that would make perfect Father's Day gifts. Choose a blooming bonsai, bougainvillea, daylily, or gardenia in a decorative pot. Or for a gift that keeps on giving, consider a citrus tree, such as a dwarf 'Eureka' lemon or 'Bearss' lime.
• Feed honeybees Draw them to your garden with flowers that they love. San Francisco landscape designer Beth Mullins (growsgreen.com or 415/336-9829) recommends the following summer bloomers for their nectar production, attractiveness to honeybees, and beautiful textures: false sea holly (Eryngium planum), honeywort (Cerinthe major ‘Purpurascens’), licorice mint (Agastache rupestris), and Miss Willmott’s ghost (Eryngium giganteum).
• Keep planting vegetables There’s still time to get beans, corn, cucumbers, eggplant, peppers, pumpkins (start now for Halloween), summer squash, and tomatoes in the ground. These warm-season plants grow well as soil heats up but need lots of irrigation, so gauge how many plants you need and can water consistently all summer.
• Plant colorful, drought-tolerant containers Instead of growing thirsty annual flowers in your pots this summer, consider colorful perennial succulents that don’t need a lot of water. Richard Ward, owner of the Dry Garden nursery in Oakland (6556 Shattuck Ave.; 510/547-3564), recommends Echeveria ‘Morning Light’ with its luminescent blue-and-pink leaves, mauve-gray Kalanchoe pumila, and baby blue Senecio mandraliscae. As fill-ins, Ward suggests sedums, whose leaf colors range from lime green and deep green to acid yellow and red. Be sure to plant in fast-draining cactus potting soil.
• Check sprinklers Turn on the irrigation system and inspect sprinklers to see if they're working properly. Replace any broken heads (often indicated by spouting water). If a head is bubbling or squirting irregularly, it may just be clogged or not sealed correctly; check slits for dirt or small pebbles before replacing the head. To readjust a head that is misaligned, rotate the head until it sprays in the right direction.
• Care for tomatoes Stake or place wire cages over tomato plants so the vining stems are supported as they grow and the fruit won’t spoil if it rests on the ground. Feed the plants with a low-nitrogen fertilizer when the fruit starts to develop (too much nitrogen encourages rampant foliage rather than more fruit). Take care not to overwater―check the soil before watering, and keep it damp but not soggy. Mulch the tomato plants to conserve moisture.
• Prune hedges To keep a mature hedge from getting any bigger, trim it after the spring growth flush ends, cutting back the new growth close to its point of origin. Taper the sides of the hedge so that the bottom is wider than the top; that way, sunlight will reach the base of the hedge and the lowest branches won’t die back.
• Water and feed roses Keep the soil moist to the full depth of the roots, about 16 inches, watering deeply every 7 to 10 days or whenever the soil is dry at a depth of 3 inches. If you haven’t done so already, apply a 2-inch layer of mulch to conserve water. Fertilize after the first flush of blooms.
• Control powdery mildew Dry summer conditions are perfect for this white fungal disease, which forms on both sides of leaves. Cosmos, crape myrtles, delphiniums, and roses can be quite susceptible to it, especially if growing in shade. Treat with a plant-based oil such as neem oil or jojoba oil, or use the biological fungicide Serenade.
Next: Grow summer herbs