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Heat damage

I have a range of plants which all seem to have suffered badly in the extreme temperatures here this week . (Daytime between 32 and 37 in the shade!). Stupidly I think I may have over compensated on some of the pots and given too much water (delphiniums were crispy so I put a saucer under now they have sat for two days in a puddle and gone droopy). Lillies are dropping all petals after just a day.... things which usually last for weeks are crisping in just a couple of days!

anyone got any tips or advice?
Marne la vallée, basically just outside Paris 🇫🇷, but definitely Scottish at heart.


  • nutcutletnutcutlet Posts: 27,312
    I think many plants grw a bit soft and lush through the cooler wet weather, the dryness and heat will affect such plants more than usual

    In the sticks near Peterborough
  • NollieNollie Posts: 7,336
    Only kind of retrospective advice, really, in that I watered very, very deeply before the heatwave hit (45 in the shade yesterday) in the hope that might set my plants up to cope better  - but there is a hell of a lot of crispiness going on and I have certainly lost a few, I think. Last night I hosed down all the leaves in the hope that that might rehydrate them, but it doesn’t seem to have worked. I think we just have to wait for it to pass and maybe cut down the sufferers in the hope that the roots will carry them through.
    Mountainous Northern Catalunya, Spain. Hot summers, cold winters.
  • BorderlineBorderline Posts: 4,700
    If you can shade the plants in extreme heat, it may help. Growing in pots tend to be more troublesome in very hot weather. The pots heat up and they suffer. In extreme heat, I put ice cubes onto the tops of containers. It does not saturate the soil, but keep them cool and slightly moist. I find, constantly watering not helpful in the heat. Some sort of cover like an awning, an umbrella or something similar will help. 
  • NollieNollie Posts: 7,336
    Good point about shade, Borderline - I did rig up some shade over prized plants but my borders are very long so I couldn’t cover everything. It was probably the searingly hot, dry wind that did for the foliage as much as the sun. I wondered if I might be doing more harm than good hosing them down last night... Love the ice cube idea!
    Mountainous Northern Catalunya, Spain. Hot summers, cold winters.
  • HelixHelix Posts: 631
    If they get too wet then they effectively suffocate!    The plant can't transpire fast enough to use the water.

    We are only a degree cooler than Paris here, and I have my tomatoes under the parasol (we’re not sitting out in this heat so we don’t need it!), have covered up window boxes with all sorts of bits and pieces, and am using cardboard boxes over smaller pots to keep the pot & plant in the shade.  I reckon having a few hours less light a day is better than frying.

    A couple of plants in the garden that have flopped badly I have taken off quite a bit of leaf to help them.  

    But it’s horrible!  I hate heat, which is why we chose to live halfway up a mountain, so I feel cheated ! 
  • BorderlineBorderline Posts: 4,700
    It's easier to cover containers, which is how I grow things now since I only have a balcony, but I think it must be tougher in open ground planting. The only way is to plan ahead. Close planting leaving no soil showing helps. Covering plants like what Helix has done will help too. Ice cubes unlikely to work if you have huge borders, but useful for containers.
  • Nice to know there are so many inventive folks on here.. I’ve just been out to check the terrace. I put up two parasols plus have been putting out the washing on the terrace which has created a bit more shade. 

    The sun is thankfully starting to move off the concrete so it should start to cool a little. 

    Am am I right that I read somewhere that delphiniums May give a second show if I cut them back after flowering? If I did this now with the crispy growth do you think they may come back once this crate heat subsides?
    Marne la vallée, basically just outside Paris 🇫🇷, but definitely Scottish at heart.
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