Posted: Monday 3 December 2012
by James Alexander-Sinclair
Today we got our first proper frost, so it's time to dig up dahlia tubers - and any tender perennials you have in pots should really have been brought in yesterday.
Today we got our first proper frost. The roofs of the buildings are dusted with white, the grass is crispy underfoot and the seedheads are glittering with ice - at least they are when the sun breaks through the lowering cloud. All very lovely, except for the fact that it’s a little chilly around my feet as I sit in the office. Time to dust off the thermal socks, I fear.
I suppose it’s particularly appropriate that the frost should come on 1 December. If I were more organised, I could tell you the date when the first frost arrived last year - but I’m not, so I have absolutely no idea. Sorry.
Anyway, things to do now the frost has finally arrived…
First, this is the time to dig up dahlia tubers and bring them in for the winter. The foliage will now be dark and droopy and rapidly on its way to becoming complete mush. There is no chance of any more flowers until next summer. So cut down your plants and dig up the conglomeration of dangling tubers you will find underground. Clean off as much of the wet soil as possible and store the energy-packed tubers in a dry, frost-free place until spring.
I have decided to try a bit of an experiment this year and am going to leave some of my dahlia tubers in the ground. Instead of digging them up, I will cover them with a generous mound of compost. I will then hope that this winter is not too dreadful, and will worry about them until (with luck) the first shoot appears in May.
Second, any tender perennials that you have in pots should really have been brought in yesterday - before the frost came. But if the frost wasn’t too hard in your area, they stand a good chance of surviving. I have a magnificent plectranthus (seen here in happier days) that is looking very sad today, so I’m just off to stash it in my mother-in-law’s greenhouse for the winter.
Third - and this is very positive news - the frosty snap will have done wonders for your parsnip crop. Parsnips need a bit of cold to give them the wonderful sweetness that makes them the perfect accompaniment to Sunday lunches throughout the winter
See, not everything about frost is bad for the gardener.