Keep It Up -- Continue to plant container-grown trees, shrubs, perennial flowers, perennial herbs, and ground covers.
What To Plant -- Plant warm-season annual flowers and vegetables (tomatoes, peppers, marigolds, petunias and the like) and citrus and other subtropicals as long as all danger of frost has passed but in enough time for them to beat the summer heat. (However, in hot low-desert areas, for example, that can mean no later than then end of February.) If in doubt, give a quick call to the garden center nearest you.
- Those warm-season annuals include plants for containers, pots, windowboxes, and planters. Work in a slow-release fertilizer at planting time. If there are perennials or shrubs in the container, simply work the slow-release fertilizer into the top inch or so of soil.
- Once the soil has warmed to 60 degrees F, plant seeds for corn, green beans, cucumbers, squashes, and other heat-lovers. That means the soil is warm enough for you to walk on it comfortably barefoot, or it's two weeks past your region's last average frost date.
- Continue to mow your lawn regularly and at the right height. It's the best thing you can do to control weeds and keep grass thick and healthy. Now, during cool weather, mow cool-season lawns such as bluegrass, ryegrasses, or fescues at 2 inches or so. Raise the mower to 3 inches once temperatures start hitting the 90s. Mow warm-season grasses such as Bermuda, St. Augustine, and zoysia at 2 inches throughout the growing season.
Dividing Perennials -- Divide most perennials once they've sent up significant foliage at least a couple inches tall. Divide them if they are getting crowded (reduced blooms, a dead spot in the middle) or you simply want more plants.
Deadheading 101 -- Deadhead spent flower heads on spring-blooming bulbs to direct their energy back to their roots so they can build vigor for next year. However, if the bulbs were pre-chilled, don't bother. They won't, unfortunately, be returning in any case.
Fertilizers -- Fertilize roses and perennials and keep them watered as needed, especially new plantings.
- Now that you're likely to have out containers of flowers, fertilize those regularly, too, with a half-strength fertilizer.
- Fertilize citrus and avocado trees now and continue throughout the warm months of the year.
- Keep up with the harvest of cool-season crops, such as peas, lettuces, and spinach. It will encourage more production. Continue to plant successions of these fast-growers for production over the next several weeks.
- Once all danger of frost is passed, prune frost-damaged plants but don't fertilize them for a couple of weeks after the frost date.
- Mulch new areas and replenish mulch in other areas so that it's 2-3 inches deep.
- Pinch the tips of fuchsias to make them bushier.
- Prune camellias after they're done blooming as well as subtropical hibiscus.
- Control snails and bait for ants.
- Move houseplants outdoors or out from protected spots, if you like. Keep them in a shady spot, however, or they're likely to get sun scald.
- If conditions are dry, spider mites may well be starting to take hold. Control them by giving affected plants a strong daily blast with the hose, being sure to get underneath the leaves. This has the nice side effect of also reducing aphid populations.