Check for signs of growth
Did you remember to plant bulbs last fall? If not, cut forsythia or magnolia branches to bring inside for forcing to get a dose of early spring color.
Prep the beds
Remove winter mulch or, if well composted, work into the top layer of the soil. Work in some leaf mold or well-rotted manure, too.
Now is the time to trim fruit trees if you didn't prune in winter. Prune before buds begin to break into bloom or you'll stress the tree and get a tiny crop (or possibly none).
Before plants have begun spring growth is a good time to divide many perennials.
Perform basic maintenance
Check stonework for frost damage. Check and clean the deck now so you don't have to do it later and make any repairs needed.
Start seeds indoors
You've spent the winter reading seed and plant catalogs, so try some.
Hardy vegetables, such as onions, potatoes, artichokes, and some lettuces, should be planted now.
Build new flower beds
This year, install complementary shrubs offering blooms throughout the season.
Stop feeding the birds
Take down and clean feeders, put them away until fall.
Plant hardy annuals
Sow seeds outdoors or transplant seedlings.
If you mulch now, you'll have next-to-no weeding come summer.
Remove spent blossoms from spring-flowering bulbs; let foliage die back without removing it.
Pick out flats of your favorite bedding plants; remember to pick ones not yet in bloom for stronger plants.
Prune spring-flowering shrubs
Trim away spent blooms, and thin too-thick branches to rejuvenate older plants.