- 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.