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Seasonal jobs for the month: August
1. Ensure container grown camellias do not dry out – they are forming next year’s flower buds at this time of year.
2. Sow Oriental vegetables such as mibuna and mustard greens for salad leaves - they bolt less at this time of year.
3. Give deciduous and evergreen hedges their final trim of the year. Ideally, clip so they are one third wider at the base than the top to minimise snow damage.
4. Harvest onions and shallots when the stems are dry and papery, and soft-neck cultivars of garlic when the neck bends over naturally.
5. Complete harvesting second early potatoes and begin to harvest main crop cultivars when plants begin to flower.
6. Autumn flowering bulbs, such as colchicum, can be purchased now and should be planted as soon as possible.

Kitchen garden

  • Sow salad onions and Japanese onions for harvesting next summer.
  • Plant strawberry plants propagated from runners into prepared ground for fruiting next year.
  • Stop outdoor tomatoes after setting four trusses of fruit. The summer will now be too short to ripen any additional trusses.
  • Ensure fast maturing vegetable such as courgettes and green beans are regularly picked in order to maximise yield.

Glasshouse & Indoors

  • Damp down greenhouse floors and staging to raise humidity and reduce incidence of red spider mite.
  • Check heaters are in working order in preparation for colder night temperatures
  • Continue taking cuttings of pelargoniums, fuchsias and other half-hardy shrubs.

Pest, disease and disorder watch

  • Powdery Mildew can occur in warm, dry weather on leaves and stems. Spray with a fungicide and avoid stressing the plant with erratic watering which can assist infection.
  • Manually remove slugs and snails, particularly on heavy soils and in wet summers.
  • Treat container plants against vine weevil larvae with either nematodes or a soil-drench insecticide.
  • Where late blight has struck potatoes harvest all tubers immediately to avoid rotting in store.

Trees, shrubs, hedges and climbers

  • Hedges are best given their final cut this month to keep them neat throughout the autumn and winter.
  • Ensure hedges are clipped one-third wider at the base than at the top to minimise snow damage in winter.
  • Trim lavender lightly to remove the old flower heads and to encourage new side shoots.
  • Summer prune wisteria, which should have new laterals shortened to 5 buds, along with apple and pear espaliers and cordons.

Flower garden / Ponds and water features

  • Dahlias are at their peak this month. Regularly deadhead plants to ensure a continuous production of new flower buds.
  • Cut back hardy geraniums and other perennials that have finished flowering to tidy them up and encourage fresh leaves and flowers in the autumn.
  • Continue to feed container plants with a high potassium fertiliser to encourage flowering into the autumn
  • Keep ponds topped up with water during dry spells
  • Thin overgrown oxygenating plants and remove blanket weed as required.

Lawns and Meadows

  • Raise the blades on mowers and reduce frequency of mowing in hot, dry weather.
  • Feed lawns with an autumn feed which will toughen the grass ready for overwintering.
  • Summer meadows can be cut now if their flowering has finished and seed heads have ripened.
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