Southern California Coastal & Inland Valleys
Tomatoes are the ONLY summer veggie that will tolerate cool soils. But do get them planted into your garden beds as soon as possible so their roots can settle in before air temperatures warm too much more. And remember to plant them deeply so rootlets can develop all the way along the stem: remove all but the top three leaflets, then plant up to them so only 1-2 inches peeks out from the soil.
Wait To Plant Other Warm-Season Veggies
As anxious as you are -- even salivating -- to get those seeds and baby plants of other summer veggies into the ground, wait until temperatures even out on the warmish side, like they were prior to our rainstorms and snow! This includes beans, corn, cucumbers, eggplants, melons, peppers, pumpkins, and squash. They will do better when they have consistently warm soil and air temperatures. Planting them into the soil when air temperatures are still cool results in growth stress which is difficult for the plants to overcome. Peppers, especially, will just "sulk" if their roots are chilled, and they won't recuperate quickly. Best to just wait till the soil has warmed before planting them.
Plant Fruit Trees
The weather from now through June is ideal for planting citrus, avocados, and other tender trees such as kiwis, kumquats, and pomegranates. In frost-free areas, also try cherimoya, guava, mango, and passion fruit. For containers, be sure to choose dwarf types. For the best choice in citrus, look for trees with many strong branches, a smooth graft union, and deep green leaves.
Prune Frost Damage...or Wait
Prune frost-damaged wood once the plant or tree has completely leafed out and you can easily see just what wood is dead. If you're in doubt, wait another month to avoid pruning wood which was just late in leafing out. By mid-summer, any remaining deadwood will be obvious.
Clean Up Groundcovers
Plant or prune ground covers to clear dead portions and stimulate new growth, including iceplant, ivy, potentilla, and wild strawberrry. Drought-tolerant choices include coyote bush, creeping coprosma, gazania, Mexican evening primrose, rosemary, and verbena.