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Splitting dahlias

Hi moved to my new home over a year ago, left garden to see what grew and where. 2 huge dahlias came up, dont know type but black foliage, yellow and purple flowers. Need to split them but still in ground now. Can I split them now or wait until they start to come through, or lift them later in year? 


  • LoxleyLoxley Posts: 5,690
    Why do you need to split them, are they just too big?

    There's a guide here, you could lift and divide now and replant immediately or pot on (I think I would pot on). You'll be overflowing with plants by the sound of it, your friends and neighbours will be happy!
    "What is hateful to you, do not do to your neighbour". 
  • Hi, yes huge, extremely huge lol. Yes there will be a lot of gifting happening. I love dahlias, I've bought 2 others to plant. My daughter bought 2 last year. So lots of splitting and sharing. Cant wait to see my borders in summer. Thanks for your advice. My grandad, long gone, also had a passion for them. He always wintered them in his potting shed. Never seen him split this time of year. I feel he's with me now, my instinct was to do it now, but didn't want to kill them as when they came through last year they reminded me of him. Thank you again
  • BiljeBilje Posts: 796
    Another vote for lift now and pot up. Whenever I leave tubers in the ground come Spring the slugs think they've found a four * hotel buffet. Not sure if you know but dahlias reshoot from the base of last years stem. If you find bits of detached tuber they won't grow. Good luck.
  • Thank you
  • FireFire Posts: 18,983
    I was going to wait until April so that plants aren't stressed by frost.
  • Good idea, I'm on North Yorkshire coast. However, it's a sheltered spot in my garden, south facing, against the house. May leave it a couple of weeks, or put them in pots for now
  • LoxleyLoxley Posts: 5,690
    Forgot to post my link How to Dig and Divide Dahlias (

    Sounds like you would have to actively try if you wanted to kill that massive clump, so don't worry too much.

    Last year I had Dahlias successfully overwinter not in the ground, but on the ground. I didn't want them anymore so I just threw them into the border. They started shooting in April, and made new roots into the ground. (It was a mild one but they must have got frosted a couple of times).
    "What is hateful to you, do not do to your neighbour". 
  • FireFire Posts: 18,983
    I dearly love my dahlias (all in large pots). I'm not wanting to take any risks with them. Slugs haven't been a problem as they are far off the ground and now very established. I suspect the tuber are huge, so it will be my first time splitting them. Lots of gifting going on.
  • LoxleyLoxley Posts: 5,690
    I tried some in the ground last year and the slugs ate every damn flower bud before it opened!
    "What is hateful to you, do not do to your neighbour". 
  • We have hedgehogs in our gardens. I grew potatoes in sacks last year, slugs ate those but not dahlias lol
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