heatwave – Charlton and Blackheath Amateur Horticultural Society

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.

Our previous post was all about how well the garden was growing – and it really was – except it then just stopped raining, for ever! At the beginning of July, everything was looking nice and green:

Amelanchier or Juneberry tree — Peace Garden

But as the Summer heatwave went on, and ever hotter, the volunteers spent more time working in the shade..

Jane weeding and tidying — Barbara in the Poppies

And pretty soon all we were doing was watering. It has been heart-warming to see the volunteers arriving every Tuesday or Thursday, picking up their watering cans and setting off to save many of the plants we planted in to the Old Pond Garden just last year. We have lost remarkably few in the end, and as long as we don’t have a repeat heatwave/drought next year, most should get their roots down and become more resilient for the future. There have been a few casualties, and a few that clearly don’t like where they are. So as soon as Autumn comes, Jason will be directing some tweaks. As August came around, the garden’s colours and textures changed to become Autumnal.

Tag: heatwave

Weather winners and losers

OPG Diary – July / August