Dallying with the dahlias.  A memorable line from Somerset Maugham, I think.  Travels with my Aunt I believe.

For some time out of favour with gardeners, dhalias are, making a comeback.

The advice generally is to lift dahlia tubers in autumn to store over winter.  Plants can also be left in situ.  Use straw for insulation, applying a thick layer of mulch to protect roots from frost.

We planted a couple of dahlia early summer 2018.  One plant survived – in a sunny patch under the far cherry tree.  It’s produced deep red flowers.  Not huge dinner-plate dahlia sized, but lovely all the same and quite surprisingly visible from the flat through the window.