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White spots on Lobelia Cascade leaves - disease?

msqingxiaomsqingxiao Posts: 482
in Plants
I grew some Lobelia Cascade from seeds, and it's been good until I moved them outdoors. Some white spots appeared on the leaves. Wonder what disease it is and if there's anything I can do about it please? Thanks!



Posts

  • Pete.8Pete.8 Posts: 11,340
    Looks like sunburn to me.
    If they've been inside for most of their lives and then put out and hit by strong sunshine, the leaves haven't had time to adapt to the strong sunlight, so they got sunburn - just like we would.
    They will adapt, but maybe somewhere with a little shade for a few days to get them used to being outside

    Billericay - Essex

    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • msqingxiaomsqingxiao Posts: 482
    Pete.8 said:
    Looks like sunburn to me.
    If they've been inside for most of their lives and then put out and hit by strong sunshine, the leaves haven't had time to adapt to the strong sunlight, so they got sunburn - just like we would.
    They will adapt, but maybe somewhere with a little shade for a few days to get them used to being outside
    Thanks a lot Pete! That'll explain it as I left them on a south facing patio... Will bring them to a more shady area then.  :)
  • Pete.8Pete.8 Posts: 11,340
    Good idea - they'll harden-off in a few days and then be able to enjoy the full sun 😎

    Billericay - Essex

    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • JennyJJennyJ Posts: 10,576
    Have they been watered from overhead? It looks to me like damage from sun being magnified by drops of water sitting on the leaves. Try to water the compost not the leaves - it helps to take the rose off the watering can.
    Doncaster, South Yorkshire. Soil type: sandy, well-drained
  • msqingxiaomsqingxiao Posts: 482
    JennyJ said:
    Have they been watered from overhead? It looks to me like damage from sun being magnified by drops of water sitting on the leaves. Try to water the compost not the leaves - it helps to take the rose off the watering can.
    Yes you are spot on too  :p I've been showering them... Will be more careful when watering going forward. Thanks for the great advice!
  • Pete.8Pete.8 Posts: 11,340
    It's a bit of a myth as far as water droplets causing burns on plants. They don't.
    They get sprinkled with water when a rain shower occurs on a sunny day and don't get burned.

    A water droplet on a leaf cannot focus light to cause burns. It would have to hover above the leaf to focus the light in order to cause a burn, but Jenny's advice is sound - best not to water leaves as it can encourage fungi.

    Billericay - Essex

    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • JennyJJennyJ Posts: 10,576
    Must be coincidence that I've had brown patches appearing on newly-put-outside bedding plants after the helpful undergardener has watered them from overhead in the sun then :) . Established hardened-off plants or the hardy stuff that grows outside is unaffected, I agree. But whatever, there's an added benefit that less water is needed if it's directed into the compost/soil and not onto leaves where it evaporates or runs off onto the ground.
    Doncaster, South Yorkshire. Soil type: sandy, well-drained
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