Jobs to do in the garden in May

With the days getting longer and the temperature warming up everything in the garden starts to put on a massive growth (including weeds!) so there are a number of key jobs to do this month:

  • Support plants such as peonies, delphiniums and lilies.  This is much easier to do before the plant puts on loads of growth.
  • Watch out for the red lily beetle  and remove the adult red beetle
  • Prune spring flowering shrubs such as Syringa, Forsythia, Choisya, Ribes sanguineum and Kerria japonica once they have finished flowering.  With Forsythia and Ribes sanguineum remove one in three of the oldest branches each year and with Kerria japonica thin out old stems to keep its size and shape.
  • Prune overgrown camellias once they have finished flowering.  Using a pruning saw reduce the height of the plant cutting back large, heavy branches in stages to reduce tearing and prune back side shoots with loppers.  The aim is to reduce the plant height to about 60 cm so it will resemble a small wooden stump but before long new shoots will start growing.
  • Lightly trim evergreen shrubs such as Pittosporum to retain their shape and lightly clip evergreen hedges first checking for any nesting birds.
  • Life and divide overgrown daffodil clumps by gently separating the offsets from the parent bulb and replanting immediately.
  • Wait until all risk of frost has passed to plant out overwintered dahlias and cannas.
  • At the end of the month carry out the ‘Chelsea chop’ on late-flowering herbaceous perennials such as Sedum, Rudbeckia and Helenium.  I did this for the first time last year with half of my Sedum spectibile ‘Autumn Joy’ and was really pleased with the result which was a much more compact plant with no ‘flopping’ so am going to do all of them this year!
  • Continue to thoroughly water in newly planted shrubs and plants especially roses which need a lot of water to begin with.
  • Continue weeding!