Growing under cover entails the use of any of the following — agreenhouse, polytunnel, cold frame, cloche, conservatory or kitchen windowsill. The resulting faster germination and protection from frost is often said to add six weeks to the start and end of the growing season for any plant. Potting sheds with large glass windows can also be used for early seed-sowing, and the use of horticultural materials such as fleeces and meshes can additionally provide protection and increase growing times.