Ever since we got our first blackcurrant bush about 2 years ago I've been waiting to take a cutting from it in order to increase the potential amount of fruit we enjoy. Yesterday was the day. New year's day. It is recommended to take cutting in about October or November so that they will get a good chance to root before the next growing season, but I have been a bit lazy and only got round to it now. You choose a good strong branch that has just grown in the current year.
I chose a branch that I would be removing anyway while pruning so as not to waste anything (the one with the arrow pointing at it). I wanted to remove this branch so as to create an airy centre to the bush. It seems to be important to allow plenty of air to circulate around a blackcurrant bush so as to prevent diseases. I'm confused about pruning blackcurrant bushes after this and so I just left it alone. I will be experimenting with my new bush in the future hopefully.
I read that you should cut the branch off just below a bud, making a horizontal cut. It is important to have a good set of pruners so as not to tear the fibres thus preventing infection of the bush.
Your cutting should be about 1ft (30cm) long.
Then you cut off the top piece of the branch, making a diagonal cut. I did this just above the first good sized bud.
The reason you make a diagonal cut here is to facilitate rain water run off. You don't want to make the cut too slanty though. If you do this you will be increasing the area of exposed branch and this too can cause infection. The one I did possibly could have been slightly less inclined. When the rain falls on the top of the cutting it should flow off rather than sitting there encouraging rot.
You then either put the cutting into a trench in the ground or a pot like I have done. As I don't know where I will be living next year I thought it would be better to go with the pot. I used a mixture of old potting compost and garden soil. This is one bit I'm not 100% sure of so I'll let you know how I get on!
Here is my garden supervisor and cleaner upper. He follows us around in the garden as we disturb the soil, revealing plenty of lovely insects. Bury the cutting to a depth of about 4 inches or 10cm, covering some buds in the process. This encourages a multistemmed bush which is what you are looking for in a blackcurrant. In other words more than one stem grows out from the ground.
Your new cutting should be put somewhere not too sunny and a bit sheltered and left until very clear signs of growth appear. I would leave it a whole year before disturbing just to make sure it has plenty of roots and will survive a transplant. If you are doing this in a pot as I have done make sure the pot doesn't dry out at all.
Good luck and I'll let you know how I get on.