May Gardening Tips


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 2½ inch height
  • Begin watering program as necessary
  • Begin weeding
  • Aerate and moisten compost pile to speed decomposition
  • Mulch azaleas, rhododendrons, and other ericaceous ornamentals with acid mulch
  • Mulch 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 gladiolas and dahlias after last frost date
  • Plant caladium and tuberous begonias in shady spots
  • Complete reseeding bare lawn areas

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 repotting houseplants as needed
  • Take out houseplants as temperatures moderate; move to partially shaded, wind-protected location

* These gardening tips are applicable for the southeastern New York region - USDA Plant Hardiness Zones 6a and 6b which include New York City, northern New Jersey, Rockland county, Westchester county, 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. If you live in a more southerly plant hardiness zone, you can start gardening earlier in the season or in more northerly zones, you can start later. 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.

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