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Need help with unhappy Phlox

Hi all,

I'm having issues with 2 phlox plants I have - 1 more so than the other. They were both planted about 4-6 weeks ago and were happy and thriving until a week or so ago. Both look like they're dying at the base with saggy yellowing leaves, but the top part of the plant is fine and flowers are still good. The purple one started sagging to one side about a week ago, and last night when it was windy over half the plant broke off (at 3 separate times within a 30 min period).

Google suggested root rot, so I gently dug the purple one out but the roots seem ok to me. Smaller than I would have expected but they don't seem to be rotting - although I could be wrong. I'd love any ideas and tips you have please. I'm also hoping to try and (somehow) get the parts that fell off to re root so I'll be planting them in little pots today. If you have any suggestions for that it would also be appreciated.

The photos I've added below are now, and then the last one is from yesterday before it fell apart. Not the best angle but I didn't take the photo expecting to have to show what the plant used to look like! 


  • In my experience it’s quite normal for the older leaves to fade and die off, particularly towards the end of the season when the whole plant will die back. 

    Some people treat them as an annual and get fresh plants each year, but if they’re in a generously sized container of loam based compost e.g. John Innes No 2 formulation, they will last a few years. 

    Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.

  • Hi

    Plox do die off in autumn and winter. Have you had any frost? That will affect the leaves.

    I dont know the actual rules around cutting phlox back. I always do it in autumn but you can leave the stalks until spring. It should then come back next year.

    Hope that this helps 😁
  • Ah, sorry, I should have added I'm in Sydney, so it's only mid spring here. 
  • FairygirlFairygirl Posts: 54,860
    They look perfectly normal to me too.  :)
    End of season, so many plants will be looking like that, or already do.
    Yes - just  pot up  individually the bits you say have fallen away, assuming they have some viable roots, and tuck them somewhere sheltered. It would be a good idea to cut back any flowers on those. 
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
  • @Fairygirl no roots at all on the bits that broke away :( The broke off above the soil. 

  • FairygirlFairygirl Posts: 54,860
    edited November 2020
    They're gone then. You could try treating them as cuttings, but I don't know if that's really viable. They might even root in water if you strip the lower leaves off. 
    There's a thread somewhere about that.  :)

    Here's the link
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
  • @Fairygirl thanks. I cut off the lower leaves last night and put them in water. Fingers crossed!
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