We have now arrived at the time of the year when we have to start planning what to do with our Cannas over the winter. Last Saturday saw the temperature drop to 8Deg Centigrade, which is low enough to start slowing down the excellent growth that Cannas should be making during September, when they come to a crescendo of flowers and new foliage.
Those with only a few Cannas to look after can decide to bring indoors into a conservatory and keep them growing over the winter, as Canna is a 52 week plant, or to wait until the frosts and move the plants indoors into a garage or shed after cutting down the foliage.
Our approach is to dig the plants out of the beds in which they are growing, using a garden fork to minimise damage, and to retain about a third of the plant, which is then planted in soil inside one of our three poly tunnels. This involves a lot of work, but will provide much new compost from the foliage and stalks.
Canna is a plant from the tropics and sub-tropics, and just being under the ground and inside a tunnel is not enough protection from the winter weather, as last year we recorded temperature of -10F in the main tunnel, so we will also cover the plants with horticultural fleece. Those with small unheated greenhouses may be able to do the same.
Others prefer to remove all soil, wash and allow to dry for a few days and then store in damp newpaper, vermiculite or perlite in dry conditions about 8F.