If a particularly cold night is forecast you can cover them up for the night and uncover in the morning. Horticultural fleece is ideal but something like old net curtains, a big cardboard box upturned over them, or even several thicknesses of newspaper will do the job.
Doncaster, South Yorkshire. Soil type: sandy, well-drained
Mine are showing new growth outside, albeit in very sunny, sheltered spots. They're hidcote too.
Your climate up in London is warmer still than mine down here in Kent. especially night/early morning. I commute into London and I've noticed everything looks a week or two more advanced up there.
I had bought 6 Hidcote in February last year, planted them in bigger pots, and kept them in the greenhouse. Despite the cold weather I had too plant them out on May 2 as I had no space left in the greenhouse. All plants survived and look healthy, but this winter has been generous with us. I'm in the South West and we had night frost and day temperature at around 5 degrees Celsius until the second week of May 2021. That Spring 2021 taught me a lot about what survives.
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Your climate up in London is warmer still than mine down here in Kent. especially night/early morning. I commute into London and I've noticed everything looks a week or two more advanced up there.
I'm in the South West and we had night frost and day temperature at around 5 degrees Celsius until the second week of May 2021.
That Spring 2021 taught me a lot about what survives.
I ♥ my garden.