Robert also built a frame for carrots yesterday. It is about 18" high and we will cover it will fleece (out the pound shop) and net curtains (Ikea) to keep the carrot fly away. This has been very successful over the last two years. We stored our carrots in boxes of sand over the winter and only ran out in February so would recommend that too.
Carrot seeds not in yet but in the next week or so. I think we have plenty of time.