Today’s video is of Will Giles explaining how to overwinter Cannas, helping you make sure you get your much loved rhizomes through the winter without them turning to brown mush (Will’s words!) . Cannas are a staple exotic plant in any exotic or tropical garden, easy to look after, cheap to buy and fast growing for maximum effect. A very rewarding exotic plant to grow, but care must be taken getting them through the UK’s cold winters. Will keeps almost all his Cannas tucked up nice and warm in his poly tunnel, which never drops below 5 degrees Celsius, even in mid winter. Will Giles explains all in this great video, in another behind the scenes look in the poly tunnels of his amazing Exotic Garden in Norwich. (Filmed April 2010)
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How to take care of Canna plants through the winter
Canna plants are tropical plants that thrive well in temperate regions. When growing in colder regions they need to be protected during winter. The gardener has the option of lifting the plants to somewhere warmer, or indoors when autumn begins or replicating the life cycle of the plants in their native regions by leaving the autumn breeze to dry out the leaves of the plant. The dried leaves then fall off and form a compost cover over the rhizome and allow new shoots to be produced. Most people in the UK dig their cannas up, and stored through the winter.
Many enthusiastic gardeners dig up them up for storage at the beginning of October which is far too soon as they are still in flower.
For those of you who haven’t grown Cannas before – they are ridiculously exotic over-the-top plants grown their fantastic foliage which range in colour from green to darkest purple, often with very large gladioli-like flower on top. In the cooler days of September through October, plants such as these put on masses of growth. As the days and nights cool down they build up large tubers to take them through the cold winter months. Cannas can be left in the ground until the first frosts blacken their leaves, which is often not until well into November here, though you can dig them up earlier if you wish.
When to dig up Cannas
They should be dug up and all the top growth removed down to about 4-6ins above ground level, then placed in a plastic pot (I use the black ones) that are only slightly bigger than the tubers, then filled with a mixture of general potting compost mixed with composted bark chippings. If, like me, you have a lot of cannas, they can be stored in a similar mix, but using large slated crates instead of pots, that will hold a dozen or more tubers depending on their size.
How to store Canna rhizomes over the winter in the UK
I store my tubers frost free under a greenhouse bench, but they would be equally happy in a garage with a blanket over them to keep out frost or any cool frost free place that isn’t to damp, as they need to be kept on the dry side to prevent mould (botrytis) forming.
How to over winter Dahlias in the UK
Dahlias can be stored in the same way though personally I leave mine in the ground as most are pretty hardy here. If you live in a frost prone area a mulch of compost or something similar can be used to a depth of about 6ins deep which will keep out the severest frost.
Dahlias and cannas can be bought during the winter months and stored ready for planting in the spring.
READ MORE: 5 Tropical winter hardy everygreen plants for UK gardens
