How to overwinter a banana plant
The banana is the largest herbaceous perennial – the stems are not at all woody, simply the agglomeration of leaf bases wrapped one around the other. It propagates itself by suckers, but the stems – and the rootstock – are unlikely to survive frosts in this country so any plants left outdoors need to be lagged to see them through the winter.
1 Before any frosts, cut away the leaves. Erect a cylinder of chicken wire around the stem and fasten it in place with bamboo canes or stout stakes to prevent wind rock.
2 Fill the framework with dry straw or bracken, arranging it around the stems of the plants and firming it down a little to add to its effective insulating properties.
3 To prevent rain from soaking the insulation material, fasten a sheet of polythene or an old compost bag across the top of the straw-filled cylinder. This will still allow air to circulate through the straw or bracken, rather than sealing in moisture. When all danger of frost has past in spring, remove the protection and tidy up the plant, removing any rotten leaves.