As spring bulbs begin emerging, sprinkle a balanced fertilizer around them. Remove the spent flower-heads, but don't cut back the foilage; let it wilt down naturally as it feeds the bulbs for next year.
It's a good idea to remove old mulches and replace with a fresh layer, especially if you've had problems with fungus diseases. Give the soil a couple of weeks exposure to fresh air and sunlight before covering with your fresh mulch.
Whether planning your garden or starting a new one, consider adding plants to attract pollinators. Besides the pleasure you'll receive from watching your garden come to life, your flowers and plants will benefit tremendously. See my section on The Birds and the Bees for some good plant choices.
Clean and hang hummingbird feeders early . . . here in the south, hummingbirds start appearing near the end of March.
Welcome the bluebirds for spring nesting by cleaning out bluebird boxes early, or put up some new ones.
Early-spring bloomers, such as forsythia, spirea and quince can be pruned after blossoms are spent.
A handy way to space those seeds or seedlings -- grab a flower pot the size of the space recommended on the seed packet ( 2-inches, 4-inches, etc ...), turn it upside-down, and 'stamp' circles in the soil, making the edges of the circles just touch. Plant your seeds where the circles meet.
When shopping for annuals for your spring beds, choose plants with the fewest full blooms . . . buds are great, but the more blooms there are, the more danger of the plant being rootbound. It will take longer to get a good start once set out.
Early spring is the best time of year for transplanting root-bound houseplants. Select a pot 2 - 4 inches larger than the old one, and use a good quality potting mix. Prune and shape up leggy plants, and begin fertilizing again now.