Is it just me or is there anyone else who didn’t know that blackcurrants were banned in the US until 1966 because they allow for a certain fungus to pass onto pines? (1)
Lucky for us, this ban was lifted in the latter half of the 20th century, and now we can enjoy this berry that’s rich in antioxidants.
We can legally buy it, but that doesn’t tell us how to care for it properly in order to get a bumper crop.
One trick is pruning at the right time and with the right technique. Here are some tips that can help you out.
Let’s get started!
When To Prune
Currants are shade-loving perennial plants that you should trim every so often if you want them to thrive. The best time to cut back blackcurrants is while they’re in dormancy, or rather during winter.
Anytime between November and February is perfect for giving these bushes a nice trim.
Pruning your blackcurrants during the winter season allows you to get rid of old wood that doesn’t bear berries any longer and encourage your bush to push out new and productive shoots.
This method will keep your blackcurrants healthy and give you the large yield you’re hoping for.
And since these bushes are deciduous, winter pruning allows you to assess the situation without leaves in the way, blocking your view. That way, you can make a sturdy framework of shoots that will carry the next season’s fruit.
Just make sure to finish pruning before your branches start to bud in spring.
How To Prune
The first thing you should know about pruning blackcurrants is that you must always use sharp and clean pruners that you disinfect afterwards. This will give you clean cuts without damaging the shoots and transferring bacteria or fungi.
If you have newly planted blackcurrants, you should cut them back to about 3 inches above ground. In the following two years, just do some light pruning where you remove weak and broken stems.
Once your blackcurrant bushes establish and you notice some real growth, you should start giving them more than a light trim. Prune them every year to have them thriving and producing new wood that will increase your harvest.
However, never remove more than a third of the entire bush at once because that can make it difficult for your blackcurrant to recover.
Here is a step-by-step guide to pruning that can help you:
Step 1. Take a good look at your blackcurrant bush and assess the situation. Start by removing the weak, damaged, dead, diseased, or broken branches.
Step 2. Once you’re done with that, move on to the stems that cross over. These can damage the bark and create an opening for diseases to enter.
Step 3. The next on the list is old wood. Get rid of up to a third of it to encourage new wood production. You can recognize old wood by its darkest bark shade. Cut these branches as close to the ground as possible, which will allow young stems to push through and replace them.
Step 4. Finally, shape your blackcurrant bush into a goblet. Open the center and space the branches as equally as possible. This will ensure proper airflow, reduce the risk of fungal diseases, ensure light gets to the inner branches, and make your harvest easier.
* Remove weak and spindly branches, small shoots that are growing inwards, those rising from the center, and limbs that are laying low.
Here are some more tips for trimming blackcurrants that can help you out:
Blackcurrants produce most fruit on their 2 and 3-year old branches, and once they are older than this, the production drops significantly. That’s why it’s important to remove these stems annually and keep your bushes producing like crazy.
Grey and healthy brown stems are the most productive ones, so you should leave them be. If there are too many of them, you can reduce their numbers to about 6-8 branches that are equally spaced with an upright growth habit.
Should You Trim Blackcurrants?
You should prune your blackcurrants once a year to keep them productive and in control. If you don’t cut them back regularly, they can become quite large and get entangled, reducing their productivity and creating a wild mess in your garden.
Old wood will not produce a lot of berries, while younger and more productive branches will struggle to push out through the mass of old wood. This all results in numerous branches, but very little berries.
And what’s worse, lack of pruning reduces the airflow inside your bushes, making it more susceptible to fungal diseases.
Can You Cut Them Back After Fruiting?
You can prune your blackcurrant bushes after harvesting them. This can make your job a lot easier in a way because you know for sure which branches are old and new wood.
However, it’s always better to prune them while they’re dormant since that reduces the stress to the plant.
The difference between old and new wood is quite obvious. Old wood is darker and more textured, while new wood is gray or brown and smooth.
References:
1. Goles, K. (2022). America’s Blackcurrant Ban. Library of Congress Blogs: In Custodia Legis, Law Librarians of Congress.