Rugosas are very hardy and should do well in the pots. However, if you live in Zone 4 or colder, I suggest sinking the pots into the compost pile up to their rims to help insulate the roots. If you don’t have a compost pile, wrap the outside of the pots in a few layers of bubblewrap to insulate the roots. The tops of the plants should be left uncovered.

It’s hard to say… you may want to shelter them in your shed if they are still small. You could also put some in the shed and some in the cold frame to ensure you have some success.

I would suggest keeping it outdoors, even if you’re just temporarily sinking the pot somewhere in the garden.

I would suggest insulating the outside of the pot if you have to keep them out for the winter. Wrap the exterior of the pot in several layers of bubblewrap or surround the pot with a cylinder of chickenwire filled with leaves or straw. The most important thing is to insulate the roots and protect them from freeze-thaw cycles. You should not cover over the crown of the plant or it could lead to rot.

Tender perennial herbs such as rosemary and thyme spend the winter in my cold frame.