The month of May is a time when the weather can either turn your garden into an Eden, or a wasteland. Be aware of the weather forecasts, trends and warnings.
It’s still not too late to fertilize your trees and shrubs. Use a Rhododendron or Evergreen type of plant food to feed evergreens and other acid loving plants like Azaleas and Rhododendrons, Camellias and Junipers, etc. Use an all-purpose garden fertilizer (10-10-10) to feed roses, deciduous shrubs and trees. Be sure to water the fertilizer in thoroughly after it is applied.
Early flowering deciduous shrubs such as Forsythias, Weigela, and Spirea should be pruned back when they have finished blooming. Cut back a third of the oldest canes to ground level, then cut back one third of the remaining branches by one third of their height.
Remove the wilting seed heads from Rhododendrons and Azaleas so that the plants energy can go to foliage growth and next years flowers, rather than seeds.
Work lime in the soil around your Hydrangeas to produce pink flowers or Aluminum Sulphate for blue blooms.
Remove any sucker growths from fruit trees as soon as they appear!
Keep a vigilante eye on the roses. Keep them sprayed for aphids and other pests and diseases such as black spot.
Pines and other conifers can be kept to a compact size by pinching off the new growth ‘candles’.
Lilacs should be pruned lightly after they finish blooming, removing sucker growths and dead blooms. Feed lilacs in May with a good all purpose 10-10-10 fertilizer after they have finished blooming. If your soil is acidic, work a little lime into the soil as well.