May

May is when the show really starts to get on the road. Everything seems to grow at once as tulips sing from their beds of wallflowers, peonies uncurl their petals and the earliest broad beans plump up nicely. It’s a good time of year to be a gardener – so here are the jobs you can be getting on with this month:

General tasks:

  • Feed the compost bin with clippings from the weekly lawn mow, mixed with drier material like straw or torn-up newspapers, to rot down into rich dark brown crumbly soil improver for your garden.
  • Lift and divide pond plants as they get too overgrown and begin crowding out their neighbours. Replant in specialist aquatic compost in perforated baskets.
  • In the case of a dry spell, keep all flowers, trees and plants well watered.
  • Keep applying a weed killer and fertiliser combination to your lawns or spot treat as an alternative.
  • Ventilate your green house well and damp down on sunny days as long as seed are not being raised.
  • If you have a pond, keep the pumps and filters running constantly and feed fish if they are near the surface.
  • Collect rainwater and investigate ways to recycle water for irrigation.
  • Check for nesting birds before clipping hedges.

Ornamental gardens

  • Repot agapanthus once they start to burst out of their pots, but don’t move them to too large a container as they flower better when they’re a little rootbound.
  • Plant tender annuals outside such as tithonias or zinnias once the weather is reliably warm; if you haven’t tried these exotic beauties, pop into the garden centre and pick up a potful today.
  • Plant out dahlia tubers once the last frost has passed, giving them a sunny spot in rich, moist soil and protecting new growth from slugs.
  • If you have planted any hanging baskets, put them in the greenhouse until the risk of frost is gone, similarly for any tender plants.
  • Deadhead spring bulbs (but do not cut the foliage back yet).
  • To prevent them from becoming overgrown, prune spring-flowering shrubs.
  • Watch for pests and treat immediately using either a chemical spray or a biological control.

Kitchen garden:

  • Harden off vegetable seedlings ready to go outside, leaving them outdoors for a little longer each day till they’re used to the cooler conditions.
  • Plant summer cabbage – you’ll find baby plants as plugs on sale in the garden centre right now. Plant 45cm apart and firm them in well after planting.
  • Sow coriander direct where it’s to grow into warm, crumbly soil. This aromatic salad herb grows really fast, so resow every three or four weeks for a continual supply.
  • Using a straw or black polythene, mulch around strawberries to prevent the fruit being spoiled.
  • If peach and nectarine are showing signs of leaf curl, destroy the affected leaves.
  • Harvest any early Rhubarb.
  • Plant a main crop of potatoes and/or earth up any early crop potatoes.