Dalias

I planted dahlia tubers in pots in March and kept them in the greenhouse; they only started to shoot a couple of weeks ago.
Look out for slugs and snails - they love the new shoots

I left my dahlias in situ in the garden last year after they had flowered and they have just started to sprout.

I did both - left one in the ground and started three in pots and mine are up about 3".

I planted one in a pot indoors in early March. I put it out in April when weather warmed up. It is now tall, 2 ft, and has big flower buds. The rest of my dahlias I planted straight into the garden in late March or early April and they are at various stages. Some are up 6inches, others only just through. We live in zone 6 climate so dahlias definately need to be lifted for the winter here.