Hardy biennials like parsley, forget-me-not (Myosotis) and foxglove can grow….

In your cold frame. Set them out in early spring, several weeks before your last frost. If you like, try pruning back marginally hardy perennials such as chrysanthemum, santolina, lavender, rosemary and sage. Hold them through winter in a cold frame. In spring, put your cold frame to work as a hardening-off chamber for seedlings indoors under lights.