if the plant is pot grown and has been kept outside it could be planted now unless your ground is totally sodden/frozen.
personally I'd wait until spring when you will be able to select a really healthy plant. But then again there may well be frost/snow then. such are the vagaries of the british weather.

My instincts said to buy and plant now because the soil is still warm given the mild weather. Besides, I'm an impatient person and once I've decided on something I want to do/buy/get it now. Instant gratification is a must at my age!

Thank you for confirming my thoughts, Seaburngirl.

I would first check the weather forecast. If there are no 'frosts' in the foreseeable future, go ahead, get the plant into the ground asap and water it in good. We still have 3 months of 'winter' to go.

However if your soil is as soggy as it is here and is at all heavy I'd wait until it drains and dries off a bit.

LOL gardening in the UK!

Well, if we don't get snow and ice we get constant rains and floods. We don't do things by halves in the UK do we?

(...and we do have some wonderful weather sometimes which more than compensates!)

fabulous

I'd wait until the one you want is in flower (with lots of buds) - only because after my 'wrong hostas' and 'wrong camellia' last year, I decided I would never buy another flowering plant without being sure that I was getting what I really wanted and not something that was mis-labelled.

You do have a good point, Urbanite. Mind you with all the rain we're having it looks like I shan't be able to plant anything till Spring anyway.

I bought a wisteria last year that was labelled as being white and which was what I wanted to brighten up the corner where the pergola is. Though it barely flowered last summer what few blooms we had were blue!

I love blue wisteria but in this instance white would have been better. So I might hold off a while with the clems.