Signs of spring are still all around in May, with trees still in blossom and fresh green leaves untouched by the summer sun. It’s a beautiful time to enjoy the garden, but don’t get too complacent. Chilly days, and even a late frost or two, can still appear. Hold off on planting out tender seedlings until they’ve been properly hardened off. Giving them time to acclimatise will reward you with stronger growth and more abundant flowers than if they were left to face the open garden too soon.
Jobs to be doing this month include:
Ornamental Garden:
This month is a fast period of growth. Late frosts may catch early blooms and soft growth – remove any damaged growth.
Spray roses with rose clear or similar.
Weed
Continue to remove spent flowers of spring bulbs but not the foliage until it has withered and yellowed.
Chelsea-chop time – If the Nepeta and Sedums are looking leggy then cutback by a third to encourage compact growth that will not collapse later in the season. This can be applied to the lavender, echinops, Echinacea, aster, helenium and salvia too if felt necessary.
Trim Rosemary, Thyme and Sage if not done in April.
Cutback withered daffodil or tulip stems once they have turned yellow.
Trim grass edges of borders regularly to keep neat and tidy.
Prune spring flowering clematis
Stake and support herbaceous perennials if necessary
If daffs gave a poor show lift and divide bulbs and replant.
Continue deadheading spring bulbs.
Start hardening off tender plants for planting out.