Chitting seed potatoes

This year we are dramatically reducing the number of seed potatoes that we are planting out after 2 years of very poor harvests. We thought we would trial a few potatoes in containers instead:

From top to bottom we have:
3 x Lady Christal - first early
3 x Charlotte - second early (RHS AGM)
2 x Rocket - first early
3 x Swift - first early

We bought the potatoes about 3 weeks ago from our local garden centre and left them in the garage. We have now brought them into the house and put them on a bright windowsill in a cool room (radiator turned off) to chit before planting out sometime in the middle of March.