Topic: What is wrong with the blackcurrants?

[Deb P]

My son's new plot is slowly being cleared, and he has found a row of what can only be described as 'very mature' blackcurrant bushes.

They stand about 5-6' tall! I decided I would cut a few back and see if they could be regenerated, but most of the stems I have cut have a black or dark brown centre to them. My other blackcurrant bushes on my plot don't have this, so I'm assuming it is a problem!

I've looked online to see if this is any particular disease, but nothing is mentioned.....any ideas/ advice please? :-\

[Robert_Brenchley]

I do't recognise the disease, but blackcurrants fruit best on young wood. Normal advice is to prune out about 1/3 of the stems each year. As they're old bushes, then I'd suggest taking out about half this year, and if they fruit reasonably, the other half next year. That would then regenerate them over two seasons. Of course, if anyone does identify a specific disease, you may have to forget this and get rid of them.

[Deb P]

Thanks Robert, I am loathe to discard them if they are salvageable at all.

[Eristic]

I reckon the dark brown centre is just heart wood due to old age. Heavy pruning should restore control.

[tonybloke]

I inherited an old redcurrant 2 years ago, stems about 3 - 4 inches thick! the dark centre in the stems is the 'heartwood' perfectly natural on a mature woody stemmer plant. cut back 1/2 of the plant this winter (to ground level), next year cut back the other 1/2. this will rejuvenate the plant. rgds, tony

[mergles]

I had the same dilemma - found overgrown blackcurrants, cleared around them, and wasn't sure if they could be productive again.  I cut half the bushes right back to about18" (sorry, too old to be metric!) above buds, and left the other half. Result - the pruned bushes fruited REALLY well this year - big fat berries full of flavour, and the others had small crinkly-skinned berries that were unusable. 
To be safe, I cut 2ft lengths from the top of the prunings and heeled them into a trench to about 9" deep. Maybe I was just lucky, but I now have 12 (out of 15) young bushes which I shall use to put into the new fruit cage I am currently building.

Good Luck!

[telboy]

Well done mergles,
Agree with your pruning advice,upward facing buds I trust, & a good muck feed!
 ;D

[Borlotti]

I have redcurrants and blackcurrants bushes on my allotment and they have got too big, so I cut them back.  Not too sure if I am doing the correct thing but have nothing to lose.  I have found that pruning often gives a good crop the next year or the year after.  I found that the really old wood just snaps off when pulled.  The birds seem to love the redcurrants but the blackcurrants seem to be OK.  Still got loads of jam in the fridge and berries in the freezer.  When I got the allotment hoped everything would grow but this year, after 5 years, seem to spend a lot of time cutting plants back as they have grown so big.

[Deb P]

Thanks for all the advice, I will prune as described and see how they go! ;D