By Piers66
Surrey,
United Kingdom 
Dahlias left in ground over winter with two shoots - should I lift and divide next year?
I had a go planting some dahlias last year, just cheap ones bought from a pound shop, but they flowered nicely. I've never grown them before, and as they cost almost nothing decided to just leave them in the ground over winter to see what happened.
They've all come up, and by covering them with clear pots I seem to have kept the slugs at bay.
I notice that all three are growing with two stems coming up out of the ground. Does this mean that they've grown extra tubers? That is, does each stem come from a potentially separate plant?
Assuming it's too late now to do it this year, should I really lift and divide them this winter?
Any general advice gratefully received!
27 May, 2019
Answers
Hi, I agree with Sbg, if you want to take cuttings next year, you're better off lifting them,keeping them frost free until mid february, then starting them into growth in a heated greenhouse, you can get lots of cuttings, as long as you leave at least 1/4" of the shoot, each shoot wil then produce 2 more shoots, 1 of which you can take another cutting from, and let the other 1 grow on, this will produce 2 more shoots, which will make the plant more bushy, Derek.
27 May, 2019
I would leave them now since they are in active growth. A lot depends on variety which comes down to genetics and a discerning breeder. I never lift mine: some return, others don't.
27 May, 2019
I don't lift mine and unless we have really bad winters they come through ok. I do bury them deeply though.
from the tubers you get new shoots rather than 'new' tubers. depending on how deeply they are buried you can take cuttings from the main body of the plant. I think it may be a bit late this year.
27 May, 2019