Perennials: When spring bulbs emerge they are in danger of nibbling by squirrels as well as deer. A sprinkling of cayenne pepper will often deter the squirrels. Milorganite has been successfully used to prevent deer browsing. It should be applied before the deer discover the tasty tips. Give the bulbs an application of general fertilizer when they are up and growing. Do not worry about freezes or even a bit of snow.
Flowers: Pansies, violets, petunias, calendula, snapdragons and sweet alyssum can be started indoors now and planted out after hardening off in April or early May.
Vegetables and fruits: Continue pruning grapevines and fruit trees. Raised beds, at least 6 inches high, will warm up and dry out weeks before ground-level soil, especially if they are covered with black plastic mulch. Best results are obtained when the beds are prepared the previous fall.
Trees and shrubs: Weather permitting, begin fertilizing acid-loving evergreens such as azaleas, rhododendrons, holly and blueberries. As soon as the soil can be worked, plant new trees. Make sure the planting hole is adequate for the roots to spread. New trees will need an inch of water a week. A slow drip from the end of a hose is beneficial. No fertilizer is needed in the planting hole.
Lawns: Phosphorus is the culprit polluting our lakes and ponds. Using phosphorus-free fertilizer and leaving untreated grass borders around water bodies will help protect them.
Houseplants: Repot cuttings of geranium and coleus. Give the amaryllis bulb and it strappy leaves some half-strength fertilizer.
General: Biodynamic sowing, planting and harvesting takes into account the position of the moon in the constellations. This method is well established in Europe and worth further research here.