March

Lawns:

Apply pre-emergent weed controls for annual weeds. Apply by the time Dogwoods are in bloom.
Correct grade in soggy areas.
Begin mowing Bermuda grass weekly with blade set at 1 1/2 inches.
Crabgrass preventers should be applied while the forsythia in bloom.
Fertilize fescue lawns by mid-month.

Annuals:

Sow hardy annuals; scatter seeds directly where you want them to grow. The best germinators in cold, moist soil are annual phlox, bachelor buttons, calendulas, Johnny- jumpers, larkspur, love-in-a-mist, moss roses, sweet alyssums.
Protect all tender plants from any possible late frosts.
Continue to plant out all summer annuals.
Apply pre-emergent herbicides to prevent spring-germinating weeds.
Weed, water and fertilize as needed.

Perennials & Bulbs

Foliar feed early flowering bulbs after blooming with manure tea or fertilizer.
Divide and prepare new plantings. 
Prepare soil for plantings.
Water new plantings if the weather is unusually dry.
Deadhead spring-flowering bulbs to prevent seed formation.  Leave the foliage until it has yellowed & dried.
Trim ornamental grasses close to the ground before new growth starts. (Gather the dried grass & tie it together, use a saw to cut the old stems).

Trees & Shrubs

Start trees and shrubs from seed. An acorn planted now can reach 4 ft. by late summer.
 After forsythia, spirea, or other fountain-shaped, early-blossoming shrubs have flowered, cut 1/3 of the oldest canes to the ground.
Fertilize most plants as growth starts. Fertilize camellias after flowering.
Move shrubs while they are dormant to reduce risk of transplant shock.
Trim beautyberry and butterfly bush to keep it compact.
Mulch beds with seafood compost.
If you are a firm believer in one-application, time-release fertilizers, now is the time to apply these slow acting to shrubs, trees and evergreens.
Fertilize Fig trees when the buds swell.

Roses

Prune ever-blooming roses
Plant container-grown roses.
Begin weekly sprays to control black spot and mildew.
Spray bushes with dormant oil to control scale, aphids, whiteflies and spider mites,

Vegetables & Herbs

Set out more peppers, tomatoes and eggplants. Seed beans, corn, cucumbers, melons and squash.
Foliar feed with hose-end fertilizer sprayer to keep plants growing.
Set out transplants of oregano, basil, rosemary and other herbs.
Install a low-volume irrigation system and mulch.
Begin planting hot weather vegetables like okra and sweet potatoes at the end of the month.