watering – Charlton and Blackheath Amateur Horticultural Society

Weather winners and losers

NB: We have just heard about an RHS survey about the impact of the recent weather: RHS Climate Change Resilience: Heatwave Impact on Gardens which has to be completed by 30 September 2026.

Following on from Pat’s ’10 Jobs…’ tips on coping with drought and heat, we asked CABAHS members to share which plants had proved to be ‘winners’ and ‘losers’ in the recent extreme weather, to help us all make climate-change-appropriate choices in the future.

Charlton House Peace Garden, July 2026 Pomegranate, Magnolia grandiflora and perovskia are all winners — Pomegranate, *Magnolia grandiflora* and *Salvia yangii* (aka perovskia) are all winners in the Charlton House Peace Garden this year

A summary: After the spring AND summer drought of 2025 (with four of the previous five years being the warmest on record), we experienced a cold November and a wet winter (the 4th wettest on record for Southern England), with the addition of unusually low light levels in early spring. We have now had extreme drought (no rain at all since early June and counting – and there were long dry periods before that too) and, so far, several heatwaves (which is counted as three or more consecutive days over 28 degrees in London – all have been in the 30s). Of course, the heatwaves may have counted six times (starting on 22 May, 19 June, 4 July, 28 July, 2 August and 9 August respectively) but the weather hasn’t exactly cooled off much in between. In addition, Thames Water declared a hosepipe ban beginning on 23 July (though watering cans and drip-feed systems are not banned) and there’s precious little rain showing in the forecast even now.

Pat’s 10 jobs for August 2026

1. To be honest we know at the moment with the drought and the heat this column will be about the few things you can do to keep things alive. I am sure we will all have losses along the way, but remember all is not lost and will mean new planting opportunities for next year.

Fallen leaves can make an immediate mulch over damp ground, August 2026 — Impromptu mulch after watering

2. If you have weeds growing (even they are struggling at the moment!), pull out and place around plants to help hold the moisture in the soil. Make sure the weeds haven’t gone to seed and, if they have, pull the seedheads off and dispose of them.

3. Mulch the soil with anything you have to hand: your own compost, fallen leaves (as there seem to be so many) but make sure the soil is damp first so you can help lock in the moisture.

Pat’s 10 jobs for July 2026

1. Maybe in this challenging weather the best thing you can do is mulch the soil (after watering, so that the soil is moist and the mulch will retain that moisture). If you pull out weeds leave them on the surface to keep roots cool, use grass clippings if you have them but making sure to keep away from stems of plants.

2. To save water just water around the roots of plants by removing roses on watering cans and spray attachments on hoses.

Salvia 'Peach Parfait' — Salvias (‘Peach Parfait’, ‘Nachtvlinder’ and ‘Amistad’)

Salvia 'Nachtvlinder' — Salvias (‘Peach Parfait’, ‘Nachtvlinder’ and ‘Amistad’)

Old Pond Garden Diary Update (April-December 2025)

As we come up to Christmas and the end of 2025, this is a great time to look back at how the ‘Old Pond Garden’ (OPG) project has fared this year.

Christmas 2025, dressing the tree of heaven with baubles, plus garden volunteers — Tree of Heaven, *Ailanthus altissima*, dressed up for Christmas
(plus 27 garden volunteers!)

Of course, it’s not just the ‘Old Pond Garden’ project any longer, as volunteer work now covers the whole estate, but we are still fond of the OPG tag. Since April, the Garden Volunteer scheme has been run by Royal Greenwich Heritage Trust (RGHT), however considering 80% of volunteers are also CABAHS members, it’s fair to say we are still very interested and still very involved.

Sharon has taken on the crucial role of Volunteer Lead for RGHT and works with Head Gardener Jason to make sure everything runs smoothly. She posts lovely updates on the garden team’s WhatsApp after every session, keeping us all on track, and sends a report off to RGHT every month.

Here are some highlights picked from Sharon’s reports of the past few months, I make no apology that this is a rather long post – we have done a lot!

Pat’s 10 jobs for August 2025

1. Time to trim back lavender hard if it has finished flowering, but try not to cut into the old wood. If you’re lucky you may get a few late flowers.

2. And time to give that Wisteria and Campsis a hack back by removing all the whippy growth and tidying up for the autumn.

This lavender will need a cut back soon. — Promote flowers by cutting back and watering in good time.

Camellia flowering in Spring. — Promote flowers by cutting back and watering in good time.

3. Azaleas. Camellias and Rhododendrons are making their flowers for next year and need regular water at their roots or they’ll drop their buds and have no spring blooms.

Pat’s 10 jobs for July 2025

1. If herbs like thyme have finished flowering, trim them back to keep them compact and use the trimmings to do some cuttings.

2. Stake Dahlias before they get too tall and straggly or the stems may snap. Keep well watered in this dry weather.

3. To conserve water and before we get a hosepipe ban, just water around the roots of plants and mulch them if you can. Some are really suffering at the moment. So why not start sowing seeds of Eryngium giganteum ‘Miss Wilmott’s Ghost’ for a drought proof plant for next year? Loved by pollinators too.

Eryngium giganteum 'Miss Wilmott's Ghost' at Great Comp, covered in pollinators — Drought resistant plants that pollinators love: *Eryngium* and *Pseudodictamnus*

Bee on Pseudodictamnus mediterraneus (formerly Ballota) — Drought resistant plants that pollinators love: *Eryngium* and *Pseudodictamnus*

Pat’s Jobs for January 2025

1. Prune Wisteria this month and next by taking all side shoots back to 2 or 3 buds. Very old plants may need severe pruning to show off the flowers.

Very tangled wisteria waiting to be pruned — Very tangled Wisteria in need of pruning!

2. Start pruning roses in earnest although some are still unbelievably flowering. Remove any foliage with blackspot and don’t compost. Old roses respond well to hard pruning so don’t be afraid, removing all dead and dying wood and cutting stems back to above a bud.

3. I had to remove dead Clematis shoots from a Daphne Jacqueline Postill and in doing so pulled off some of the flowers so take care and do it soon if you can. But leave the main prune until next month.

The New Gardening Year

Yes, it’s that time of year again, when everyone asks you what your New Year resolutions are. The magazines and papers are full of good ideas, here are some I’m going to copy:

Don’t fence me in:

There are 22 million gardens in the UK, so they are very important for our wildlife – as long as they can get in and out! Fences are a barrier to many mammals, reptiles and even some insects, but if all those gardens had little gaps between the fences (or better still fences replaced with hedges) wildlife could move freely between them all and biodiversity would increase.

Kick the peat habit for good: