I have just put last years separated tubers into trays to start early. Should I bring them in the house or should Put them in an unheated greenhouse
If the greenhouse is unheated then it is too early. An unheated greenhouse is not reliably frost free at this time of year. If you really want to start them now then do it indoors.
Thanks for the advice I have brought them in for a couple of weeks
It's my first year with a greenhouse so I am itching to get started.
Susan, putting them outside in an unheated greenhouse is still a bit risky at this time of year with the potential for frost - particularly overnight. If you are keen to start them off (as I am now) you could pot a few up in multipurpose compost and bring them inside where they will soon begin shooting. When the shoots are well formed you could then take some cuttings and pot these in mpc to root in an electric propagator at 15 - 20 deg C. They root easily and its a great way to increase your stock for giving away to friends and this way they will come true to type.
Whhooooo I am getting shoots
Hi Susan - you can also just let the shoots continue to grow on into an established plant keeping the compost moist and the plant inside until any last frosts have passed. You can then put it outside and later on 'stop the main stem' to allow side stems to form and a more bushy plant with more flowers on display.
All the best.