Dahlias needing attention

Sue & Mutton

Every year I’m too busy doing other things In the greenhouse and garden and neglect my dahlias. No change this year! I’ve about 40 that I leave in the ground all winter in the hope some of them will succumb to the frost. Each one is now about 4’ and with about 8 stems. Although some are  flowering I need to thin them, stake them  and pinch the tops out before they all end up horizontal. How many stems would you leave? Many thanks

Bilje

If you were starting large tubers in Spring in pots after overwintering them it’s “usual” to thin the new sprouts and leave about 5. I’d think the same would be true of garden grown ones like yours. Perhaps of you cut the extra shoots right back to just above a pair of leaves they might reshoot from that point..a bit like a late Chelsea chop. 

I’m not sure I’d do any pinching back of shoots at this stage you’d lose a lot of flowers. Happy staking. 

Fire

I don't think people 'thin' a dahlia plant. Do you mean 'pinching out' ? Most people are wanting more flowering stems, not less.

Sue & Mutton

Hi, apologies for the delay - thank you for your replies. I've started to prop up the flagging plants and have "thinned" one just to see how it goes. I took off 14 2' long shoots - all from within the plant and thinner than a pencil - leaving 8 on it. Fingers crossed!