Uncle-C wrote:

Now that we have had 2-3 days of frost in the S.East of England I want
to ask if there is a chance my dahlia tubers will survive if I do not
lift them for overwintering.. Most of the foliage started to whither
after the cold temps so I've chopped the plant down to about 2-3 inches
above ground level. I would like to leave the tubers underground but
fear the wet weather / frost will do permanent damage. What would be
the best form of outdoor protection for the tubers ?

A bit of straw or compost mulch on top will keep the cold off a bit. But
even in North Yorkshire I get some that over winter when I miss them. It
depends on hold cold the winter and how waterlogged the ground and luck!

frost ? Any past experiences from "urglers" would be most helpful. I
have to get on the case fairly rapidly as there is widespread hardfrost
forecast for the next few days. Thanks.

I would lift a few of the ones you really like to be safe. Provided you
have suitable frost free dry cool storage space in a garage..

The tubers are tougher than you might think. Ditto for some daturas.
Last few days have seen off all the top growth now.

Regards,
Martin Brown