Tips for June 2026

Prune Clematis Montana after flowering. Prune overcrowded dead or diseased stems. This species tolerates hard pruning, so you can cut plants down to nearly ground level.

Harden off exotics, such as Aeoniums and Cannas, that have been overwintered indoors, to help them adjust to outdoor temperatures. Then plant out in a sunny sheltered spot and water regularly.

Gently tear away virous growth that come from ground level on trees, shrubs and roses. Do it as close as possible to prevent further  suckering, scraping away soil to reach if necessary.

Feed tomatoes in containers every 10-14 days with a high potassium liquid fertiliser once the first fruit has set. Pinch out side shoots.

This out developing plums where the crop is heavy, to avoid branches breaking under the extra weight.

Tender plants started off indoors such as aubergines, sweet corn, squashes and tomatoes can be hardened off carefully and planted out this month.

Remove spent flowers from camellias and rhododendrons. Avoid damage to brittle leaf buds as they emerge just behind the blooms.

Finish planting dahlia tubers 10-15cm deep in well  prepared enriched beds or containers of John Innes Number 3 Compost.

Hang pheromone traps in apple trees to monitor codling moth.

Stop harvesting asparagus by mid to late June so plants can form feathery frond and return energy to the roots.