Friday, 30 June 2017 08:53

May

Written by The Webmaster
  • Thin out drifts of hardy annuals.

  • Harden off half-hardy plants by leaving them outside during the day and bringing back under cover at night for 7 to 10 days before planting outdoors.

  • You can still divide herbaceous perennials now to improve their vigour and create new plants.

  • Divide Hostas as they come into growth.

  • Trim back spreading plants such as aubrieta, alyssum and candytuft after they have flowered to encourage fresh new growth and more flowers.

  • Don't be tempted to cut down or tie up the foliage of spring-flowering bulbs, let them die down naturally.

  • Trim lavender plants now, cutting off any old flower heads and about 2.5cm (1 inch) of the current year's growth.

  • To reduce the spread of forget-me-not, lift the plants now to prevent heavy self-seeding.

  • Take cuttings of tender perennials such as Fuchsia, Argyranthemum and Pelargoniums (geraniums). The new shoots of hardy perennials can also be used for cuttings.

  • Take softwood cuttings of shrubby herbs (such as sage and lemon verbena).

  • Tie in your sweet peas with plant support rings to encourage them to climb.

  • Prune spring-flowering shrubs after flowering.

  • Cut back flowered shoots of Choisya to promote a second flush of flowers in autumn.

  • Top-dress permanent pot plants to refresh the compost. • Give your container plants a balanced liquid feed every two to four weeks to promote healthy growth.

  • Plant up pots and baskets of summer bedding and harden off before placing in position. In cold areas wait until June.

  • Start to closely inspect your plants for pests and diseases - early prevention is easier than curing an infestation.

  • Pick off larvae of rosemary, viburnum and lily beetles as soon as they are seen.

  • Look out for signs of blackspot on roses. If discovered, Blackspot can be treated with a systemic fungicide.

  • Continue to weed beds and borders to prevent competition for water and nutrients.
More in this category: « April June »