With a garden full of fresh growth and abundant flowers, pruning might not be at the top of your list of jobs to do this month. However, don’t leave your secateurs in the shed, because pruning now will help to get the best performance out of many garden plants. Spring- and early summer-flowering shrubs should be pruned now (once they’ve finished flowering) to encourage strong growth that will mature to become future-flowering wood.
It’s mostly a case of clever thinning, by cutting the oldest wood out from the base. This lets in light to stimulate new growth without the shape of the shrub changing.
Early-flowering climbers, like Clematis montana, can also be pruned and trained now to keep them from swamping your plant supports. The nesting season lasts until August, so check for nests in shrubs and climbers. If you have to leave it, you can do a lighter tidy-up of damaged or dead wood later in the summer and, hopefully, get back to thinning it next year. Add perennials to your list – some can be freshened up with a trim now. Chop back the tired flower stems of alchemilla, centaurea and hardy geraniums and you’ll be rewarded with another flush of flowers within weeks.
More pruning advice:
Plants to prune now
Pruning now encourages new juvenile growth that has the rest of the season to mature. Light pruning will help to thicken growth and shape plants. Wear gloves to protect your hands from sap.
The flowers are over now, so cut the oldest stems out at the base, taking care not to damage the healthy wood as you work.
Trim back young shoots extending beyond the main structure and tie in any you want to train into shape for next year.
Variegated evergreen Elaeagnus
Prune out shoots where the leaves are reverting to green – they are more vigorous and will take over if you leave them.
All the old flower stems can be cut right back (wear gloves) to give the new shoots room to grow, ready for flowering next spring.
- Beech hedges: Beech hedges will hold the newest leaves over winter if you delay trimming until the shortening days of July or August.
- Cytisus: Broom is reluctant to grow back from older wood, so avoid pruning now, after flowering, or just give it the lightest trim on the newest growth.
- Hydrangeas: Hydrangeas – as well as buddleia – are now forming this year’s flowers, so leave them and prune early next spring.
- Wall-trained apples: These and pears need the energy provided by new shoots while the fruit is developing, so leave them until August, when you can cut them back to a bud.
Step-by-step: The Chelsea chop
The Chelsea chop is a pruning technique that can be done on early flowering perennials to stimulate a new flush of leaves and flowers. Do it straight after flowering, before the plant wastes too much energy going to seed, and it will soon push up new growth for a second performance. It works earlier in the season on brunnera and pulmonaria, and later on for alchemilla, knautia and Salvia nemorosa. Early geraniums have flower stems that sprawl out from the centre, so chop them back now to get another neat flush and save neighbouring plants from being smothered.
Lift up spent flower shoots flopping over the border and gather handfuls to hold up and cut with secateurs, rather than shears, to minimise damage to nearby plants.
Cut all the stems right back to the base so that soon, when new shoots start to appear, they will have plenty of room to grow and reform the plant’s shape.
Pull any debris out of the border, along with any weeds you’ve uncovered, then bundle them up to take to the compost heap. Chop the stems further for better composting.
Soak the clump with water if it’s a dry summer, then look forward to the rejuvenated canopy of new leaves by August – and expect more flower stems to follow, too.
The Chelsea chop will also delay flowering or reduce the flower stem heights on later flowering perennials. If you shorten the stems of plants such as Anthemis and Solidago now, it results in more sideshoots and more but smaller flowers. Late-flowering Hylotelephium ‘Herbstfreude’ will flop under the weight of its flowers, so cut shoots back by a third now and they’ll flower this summer on shorter upright stems.