One of the problems I have with blackberries is that if I let the tips touch the ground, they will quickly root; so if you want more, it is very practical. They are invasive here, so my experience is based on what not to do so I get fewer plants.

I grew blackberries once & they took over and spread like wildfire. They are delicious. I would just pulled up a few rooted canes and give them away to anyone who wanted them. They came back double the following year. I couldn't eat them fast enough. Here is a website that could help you propagate more blackberries.

https://www.gardeningknowhow.com/edible/fruits/blackberries/propagating-blackberries-cuttings.htm

yea, sure do it now, should work quite well, Maybe the one you had growing died because it got suddenly cold after such a warm February...

Thanks for the replies, will get on with it tomorrow.

They should be easy. Just take half a dozen cuttings, strip off all but the top leaves & plant them in a six inch pot of compost. Loosely cover the stalks with a plastic bag to retain moisture & leave somewhere not too bright & not too warm. Once you see small, new leaf shoots they're ready to be separated into individual pots.
Layering in blackberries may be too much fuss?

I've also got a thornless blackberry, [Thorn Free], last year as the new canes grew I fed one onto a pot & put a heavy stone on it just before the tip

As the tip grew onward I fed this into another pot, and held it down using heavy stone method

I then had two pots with a Loch Ness Monster fashion blackberry linking them, but still attached to main plant

Both rooted & I severed the link to main plant and between them this April once new leaves appeared on the "babies"

So far so good, they seem to be growing fine in the pots but not checked root growth, I'll leave that until summer when I think they are fully established

Lovely garden Hank.