Southern California Coastal & Inland Valleys
Growing Bulb Onions
Feed bulb onions with a 10-10-10 fertilizer to encourage bulbing. Sets that send up seed stalks instead of forming large bulbs were perhaps not sufficiently dormant when they were planted, or they were larger than dime-size and going to bolt soon anyway. To delay bolting, snap off the stalk at the base.
Pluck Strawberry Blooms
Pluck off strawberry blossoms through May, or whenever the warm weather has settled in for good, to concentrate the plant's first real burst of fruiting energy into large, sweet berries rather than small tart ones. Unless, of course, you're desperately waiting for that very first berry, even if it is tart.
Start Herbs From Seed
Herbs to start from seed include anise, basil, chervil, chives, cilantro (coriander), dill, fennel, lavender, marjoram, oregano, parsley, and savory. Transplant mint, rosemary, sage, tarragon, and thyme (these don't come true from seed). Herbs make great landscaping plants, as well. Chives add attractive, spear-like foliage among blooming plants. Rosemary and wooly thyme make attractive, drought-tolerant, trouble-free ground covers.
Plant Citrus and Avocado Trees
Citrus and avocado trees do best when they're planted from late this month through May, as the weather warms up. For the best protection from cold weather and frost, choose a southwest exposure that's protected from the wind. Plant them on a mound or in a raised bed so water drains away from the roots. Rub suckers off trunks as they appear. Tape together or remove broken branches. Paint trunks and large limbs with a matte-finish, off-white interior latex paint mixed half and half with water to prevent sunscald.
Plant Summer-Blooming Bulbs
Plant summer-blooming bulbs, corms, and tubers, including acidanthera, agapanthus, tuberous begonias, caladiums, calla lilies, canna lilies, dahlias, gladiolus, hemerocallis, tuberous iris, ixias, tigridias, tuberoses, and watsonias. Repeat plantings through May for continuous bloom through the summer. If you still have some unplanted spring-blooming bulbs that are firm and solid, plant them immediately in rich soil. They'll probably not bloom this year, but they'll develop further and bloom next year. If not planted, they'll shrivel away to nothing. These leftover bulbs also can be potted up for forcing. Place them in the refrigerator for eight to ten weeks, keeping the soil moist but not soggy. They should bloom after another three weeks in a brightly lit area.