There are many vegetables that can be grown in the UK during the winter months. Some of the hardy vegetables that can be grown during winter include broccoli, Brussels sprouts, cabbages, kale, leeks, parsnips, carrots, onions, turnips, and winter squash. Leafy crops such as chard, parsley, and rocket can also over-winter with a little protection. Winter hardy varieties of spring onion and salads can also be grown during winter. When selecting seeds, look for winter varieties. Most winter vegetables are sown in late spring or early summer as they take several months to reach maturity. However, some vegetables such as parsnips and Brussels sprouts are sown in spring. Containers can be used to grow a few plants if ground is in short supply. Greenhouses or polytunnels can be used to over-winter some crops and start others off early, but heating greenhouses for year-round harvests is rarely efficient.