Planning
– Plan planting areas based on exposure to sun, shade, and wind; consider distance from water source
– Test for soil types and pH levels before major planting
Chores and Maintenance
– Carefully remove winter mulches from planting beds
– Dig beds in preparation for spring planting as soon as earth is friable
– Add compost in four to six inch layers and work into planting bed soil
– Remove protective cover from evergreens
– Reset frost-heaved plants
– Apply horticultural oil sprays to dormant trees and shrubs before buds open and if there is no danger of night frost
– As ground becomes workable, de-thatch lawn; fill in low spots with soil; fertilize established lawns
Planting
– Plant deciduous and evergreen trees and shrubs, weather and soil conditions permitting
– Sow seeds of annuals and vegetables indoors that require 10 to 12 weeks before transplanting
– Sow radish and lettuce seeds directly into the vegetable garden
– Plant cold weather vegetables like spinach, peas, lettuce, and broccoli as soon as soil is workable
– Plant and transplant perennials
– Divide and transplant summer-blooming perennials
– Soak mail order bare-root plants before planting
– Plant roses
Pruning/Fertilizing
– Prune all plant material to remove any diseased, dead, weak, or crossing branches
– Complete tree pruning before new growth begins
– Prune late-flowering shrubs such as buddleia and Hydrangea paniculata but wait until after flowering on early-flowering shrubs like forsythia, Hydrangea macrophylla, rhododendron, and syringa
– Wait to prune evergreens, hedges, and other shrubs until late spring into early summer
– Prune all fruit trees before growth begins
– Prune hybrid tea roses, floribundas, and grandifloras but wait until after flowering on climbers and ramblers
– Prune back leggy perennials
– Cut back ornamental grasses to new shoots
– Fertilize deciduous, broad-leaved and needle-leaved evergreen trees and shrubs if not fed in the fall
– Apply fertilizer to roses as new growth begins
– Fertilize and lime vegetable garden
Indoors
– Begin to transplant pot-bound houseplants
– Continue to inspect for pests and control as needed
– Cut back leggy houseplants
source:http://www.nybg.org/