Fruit trees are flowering, or will soon, and if you are able to fertilize only once a year, now is the time to do it. Any granular fertilizer will do. First, determine how many square feet are under the tree's foliage canopy, and use the amount recommended on the package label. Scatter the fertilizer under the tree, making sure that you distribute it evenly, and then work it into the soil by roughing up the ground with a steel rake. If it should rain, the water will carry the fertilizer to the roots; otherwise, use a sprinkler to irrigate deeply.
If you didn't get around to planting that fruit tree you've always wanted, it's not too late. Although the bare-root season has passed, many nurseries pot up their unsold bare-root plants. Some of the advantages of bare-root planting (including price) are lost, but the trees still have time to become well-established, planted this early in the spring.
Deciduous fruit trees should be pruned by now, but if you haven't done so, do it now. Don't prune too heavily at this time of the year, however. Fruiting-flowering varieties should be cut back while they are in flower; put the branches in a vase.
Many pesticides are toxic to bees. Don't spray trees now or you'll risk killing the bees that are doing the pollinating--which will result in less fruit.
After the first week of March, there is no danger of frost (except in the mountains). All the materials used to protect plants from freezing can be put away. And then, once a few warm days have taken the chill out of the soil, planting for summer can begin.
Snails flourish at about the time daffodils start to bloom. To eliminate them, sprinkle in the late afternoon; then go hunting for them with a flashlight after dark. That is an especially successful method. Or scatter bait. Another option is to introduce decollate snails (cannibal snails) into your garden. They eat mostly snail eggs and baby snails--and old leaves as well. It's possible to be disappointed with decollate snails because three years or so must pass before results show. If you do use them, be very careful with snail bait because they'll eat it, too. However, since decollate snails are not climbers (except during heavy rains), you can put bait in raised pots, where only common snails are likely to go. Decollate snails are available from J. Harold Mitchell, 305 Agostino Road, San Gabriel 91776; telephone (818) 287-1101.
Bromeliads with pups around the base that are one-third to one-half the height of the parent can be separated, and the pups can be used to form new plants. If you use snail bait, be careful to keep it out of the plants' cups. If the colors of a bromeliad seem pale, increase the amount of light gradually.
Tuberous begonias can be started now. Place them up to their necks in slightly damp peat moss. When pink sprouts appear, plant the tubers in pots or in the ground. Once planted, they should not be moved, because their leaves won't adjust to light from a new direction. The larger-flowered types grow well near the beach, but the single-flowered varieties or the smaller, double ones (such as 'Nonstop') are best for the inland areas.
Limes make a useful and fragrant addition to yard and kitchen. Three varieties of lime trees are commonly available in nurseries: 'Bearss,' 'Mexican' and 'Rangpur.' 'Bearss' is the most practical lime for local gardens; it thrives in any of the climatic zones where lemons grow well. 'Mexican' is known as the bartender's lime and is juicier and more aromatic than other varieties; however, it is suited to only the most frost-free of areas. 'Rangpur,' which tolerates the cold quite well, is not a true lime but rather a sour mandarin orange. It is sold as a lime because its highly acid fruit makes it a useful lime substitute.
Broccoli transplants can still be planted; set out in a few weeks, however, they will probably do poorly. Warmer weather and longer days make the heads flower before they reach harvest stage.
Arugula, often listed in seed catalogues as rocket salad or roquette , is a green whose leaves have a pungent, strong watercress flavor. A handsome plant with bright-green leaves, it is no trouble to grow. It is strictly a cool-weather green, so plant it now.