Roehampton Garden Society

April jobs on your allotment

Maintaining soil and structures and planning ahead

  • Although weather is warmer, continue to listen for forecasts of frost warnings and cover vulnerable plants at night. Delay planting out cold sensitive plants if frosts are forecast.
  • Weed ‘defensively’; remove weeds before they flower to avoid seeding.
  • Continue to keep grass paths manageable by regular cutting.
    Draw up soil around the base of peas and broad beans to support them and increase the rooting area.
  • Clean greenhouse glass to improve light levels
    On sunny days ventilate the green house by morning opening and close late afternoon to conserve the heat.
  • Earth up early potatoes when they have made 8” growth.
    Plan and prepare planting holes for squashes, adding well-rotted manure.
  • Build frames for climbing beans.

Sowing and Growing

  • Sow indoors or in the greenhouse Brussels sprouts, cabbage, early leeks, cucumbers, courgettes, peppers and sweet corn.  Sow tomatoes for outdoors.
  • Sow herbs; dill, fennel, oregano and thyme, parsley from seed.
  • At the end of the month sow tender vegetables indoors, such as runner beans, squash and pumpkins.
  • Watch out for signs of damping off in seedlings which can be caused by sowing in cold, wet soil with poor drainage and air circulation and worsened by overwatering. A light covering of vermiculate reduces the problem.
  • Direct sow broad beans and early peas.
  • Make successional sowings of beetroot, Swiss chard, lettuce, radish, summer spinach, spring onions, lettuce, parsnips and turnips.
  • Thin out germinated seedlings and hoe between rows.
  • Direct sow early varieties of carrot when the ground has warmed up.  To avoid attack from carrot fly, either sow 18” above ground level or cover with insect mesh.
  • Sow annuals to attract pollinating insects such as nigella, single flowered marigolds, comos, Californian poppies.
  • Direct sow sweet peas.
  • Second early and maincrop potatoes should be planted by the end of the month.
  • Once tomatoes have their first true leaves, plant them deeply into individual pots
  • Water crops regularly in dry weather.
  • Plant out autumn-sown sweet peas.
  • Finish planting shallots.
  • Plant soft-neck garlic.
  • Plant up new asparagus and globe artichoke beds.
  • Cover radishes and turnips with horticultural fleece to protect against flea beetle.
  • Use fleece to protect blossom of trees such as pears if frost is forecast.
  • Net strawberries against bird attack.
  • Watch out for early aphid attacks. Early action by manually removing these or hard- spraying with water can reduce likelihood of damaging infestations.
  • Feed roses with rose feed.
  • Feed soft fruit with a general purpose fertilizer.
  • Pick and destroy yellowing leaves of brassicas infected with downy mildew.


  • Harvest rhubarb by pulling a few stalks at a time. Put the leaves on the compost heap.
  • The first cutting of asparagus is traditionally made after St George’s Day, 23rd April and the last cutting on the longest day, 22nd June.


  • Once leaf buds open, start formative pruning of stone fruit trees such as plum and cherry.
  • Pinch out laterals on grape vines to leave one every 30cms and tie in selected shoots.

Gardening for wildlife

  • Divide or cut back pond marginal plants.
  • Prepare a fine tilth before sowing a wildflower meadow patch of cornfield annuals to attract pollinating insects.

Comments are closed.