BARE-ROOT PLANTS. It's not too late to plant bare-root roses, fruit trees, berries, and grapes. But shop carefully: quality and selection dwindle as the temperatures warm up. If you're considering adding a low-chill peach, 'Bonita', 'Red Baron', and 'Saturn' are good choices. All three cultivars have been high scorers in taste tests at the University of California South Coast Research & Extension Center in Irvine.
COOL-SEASON VEGETABLES. In coastal (Sunset climate zones 22– 24), inland (zones 18–21), and high-desert (11) gardens, continue to seed beets, carrots, celery, chard, chives, collards, endive, fennel, kale, leeks, lettuce, mustards, onions, parsley, peas, potatoes, radish, spinach, and turnips. For a fast crop, try a micro greens mix, which you harvest when plants are only a few inches high. If you like a little bite in your salads, Micro Greens Spicy Mix from Botanical Interests of Broomfield, Colorado (www.gardentrails.com), is a great seed blend of cress, mustards, and radish.
PERENNIAL WILDFLOWERS. In the low desert (zone 13), plant coreopsis, desert marigold, evening primrose, penstemon, and salvia.
SUMMER VEGETABLES. Zone 13: plant eggplant, peppers, tomatoes, and other warm-season vegetables late this month. But be prepared to protect them with row covers or hot caps if a late frost threatens.
WINTER COLOR. Coastal and inland gardeners can fill in bare spots with calendula, cineraria, Iceland poppy, nemesia, pansy, primrose, schizanthus, snapdragons, stock, or sweet peas. If the soil is too soggy, plant in containers.
DETHATCH WARM-SEASON GRASSES. Early spring is a good time to dethatch Bermuda, Kikuyu, St. Augustine, and other warm-season grasses. Mow lawn as low as possible before starting. Then rent a dethatcher (a vertical cutter or vertical mower) and make several crisscrossing passes across the lawn to loosen the interlocking runners that hold the thatch in place. Dethatching works best on damp but not soggy soil. Rake up and dispose of loose thatch; don't compost.
DRAIN STANDING WATER. If plants are standing in pools of water, dig small, temporary trenches to let the water flow away. Or scoop out excess water with a shovel.
SPRING FEEDING. Feed ground covers, shrubs, perennials, trees, and other permanent plants with a slow-release fertilizer such as bonemeal, cottonseed meal, or well-rotted manure to provide gradual nutrition through the season. Or, if preferred, scatter a granular complete fertilizer and water well. If you're within 10 miles of the coast, also feed citrus and avocado. Cool-season lawns, like tall fescue, should be fertilized as well.
APPLY DORMANT SPRAY. While deciduous fruit trees are still leafless, spray them with horticultural oil to smother overwintering insect pests such as scale, mites, and aphids. For fungal diseases such as peach leaf curl, add lime sulfur or fixed copper to the oil, following package directions. Spray the branches, crotches, trunk, and ground beneath the tree out to the drip line.
SOWING FINE SEEDS. Some seeds, like those of parsley, Shirley poppies, and violas, can be difficult to sow evenly because they're so fine. Try this method to make the process easier.
1. Pour loose, fast-draining potting soil into a 4-inch plastic nursery pot.
2. Mix seeds with a small amount of fine sand in a plastic bag and shake well.
3. Fold a small piece of paper in half and put some of the seed-sand mixture in the crease. Lightly tap the paper over soil to distribute the seeds.
4. Mist lightly with a spray bottle of water. —Julie Chai
