What to do with tubers

Ruth considers whether to leave or lift cannas and dahlias

- Ruth Hayes

OUR cannas and dahlias have loved this summer and even thrived on the grey water they were given every now and then. But now, with nighttime temperatures dropping, it's time to start thinking about what to do with them over the winter.

In theory, if they are growing in borders, you live somewhere sheltered and your soil is light and free-draining, you can leave them where they are for winter. Reduce their top growth to 4in (10cm) and mulch their roots with a layer of well-rotted compost or manure.

There will still be a risk of losing some plants, especially if we have a very wet or cold winter, but they will stand a better chance than those growing in clay soils that hold on to water, increasing the chance of waterlogging and rotting.

I have kept and lost dahlias and cannas to winter weather over the years, and now generally prefer to lift and store them in the greenhouse.