Perennial border photo courtesy of Flickr cc/ Mark Levisay
Chores and Maintenance:
Finish preparation of planting beds
Continue to cultivate planting beds and carefully remove young weeds
Dig and divide early-blooming perennials after flowering
Lift, divide and replant late summer and fall-blooming perennials
Set supports for floppy plants, vines and vegetables
Mow lawns regularly to keep grass at 2 1/2" height
Begin watering program as necessary
Continue weeding
Aerate and moisten compost pile to speed decomposition
Mulch azaleas and rhododendrons, and other ericaceous ornamentals with acid mulch
Complete edging and mulching of planting beds
Deadhead bulbs but allow foliage to remain until yellow to nourish bulbs for next year's display
As night temperatures moderate into the 60's, move houseplants outdoors (avoid full sun and windy locations)
Look for pests and other problems; spotting early can mean less chemical controls. Note: slugs and caterpillars can be removed manually
Begin application of deer repellents
Planting:
Move self-sown annuals and perennials to desired locations
Sow seeds of corn, cucumber and melon directly in the garden
Harden off tomato, eggplant and pepper transplants before planting out at end of month
Complete planting deciduous trees and shrubs, weather and soil conditions permitting
Continue to plant and transplant perennials
Plant summer annuals after last frost date
Plant summer-flowering bulbs such as gladiolus and dahlias after last frost date
Plant caladium and tuberous begonias in shady spots
Complete re-seeding bare lawn areas
Plant summer-flowering bulbs, like this Dahlia 'Ryan C', after the last frost date
Pruning/ Fertilizing:
Pinch back late summer and fall-blooming perennials
Continue to prune all plant material to remove any diseased, dead, weak or crossing branches
Prune early spring-flowering shrubs after blooming
Wait to prune evergreens, hedges and other shrubs until late spring into early summer
Begin deadheading roses
Fertilize roses
Fertilize needle evergreens with acid type fertilizer
Fertilize bulbs as they finish blooming
Fertilize annuals and container plants
Fertilize lawns in late May (leaving grass clippings on the lawn can reduce the need to fertilize)
Indoors:
Finish re-potting houseplants as needed
Take out houseplants as temperatures moderate; move to partially shaded, wind-protected location
Fertilize needle evergreens with acid type fertilizer
*These gardening tips are applicable for an average year in the southeastern New York region: USDA Plant Hardiness Zones 7a and 7b, which include New York City, Northern New Jersey, most of Rockland and Westchester Counties, Southern Connecticut, and parts of Long Island. Plant hardiness zones refer to geographic areas where the growing season of plants is determined by the time of killing frosts in the spring and fall. Even within zones, climatic factors such as altitude, proximity to water, wind exposure, winter sun exposure and snow cover contribute to the existence of different "microclimates" and can influence plant adaptability.