I've done it successfully in the past by taking suitable shoots in winter and pushing them into the ground, but it appears that it is even easier than that.
I dug up one of my blackcurrant bushes back in the summer and threw the branches on the bonfire pile. Most were burnt but some didn't and remained on the pile with all the subsequent rubbish piled on top.
Today I lit a bonfire and underneath the pile I came across these ...
If I hadn't had that fire and just left that heap I would have ended up with a huge clump of currants, plus there were several apricot prunings with shoots and roots as well.
That's what you get for living in a damp humid climate.
