How to Prune Blackberries

in Beginner Gardens,Garden

Thank you for visiting Little House in the Suburbs. If you like what you see, please check out OUR BOOK.

Pruning holds a mystique for me.  It’s the purview of the elite, experienced horticulturist, not a bush-leaguer like me; a craft bordering on art in its extreme forms, and it scares me.

My first experience with pruning, other than hacking away at overgrown hedges, was with roses.  I read all about forming a bowl shape, maintaining air circulation, where to cut to encourage new growth in a certain direction.

That was twenty years ago and still my rose-pruning method is to address the plant, flash back upon the tutorials I’ve pored over in the past two decades, and then start hacking off whatever has been grabbing my clothes as I pass by.

Blackberries are different.  They’re yummy.  So I’m more serious about them than roses.  Here, I’ll explain some of the basics about blackberries and show how to prune them to encourage production and keep them under control.

My blackberries are upright thorny blackberries.  The instructions here apply also to upright thorn-less blackberries.  Their growth is similar, though not as aggressive as the thorny variety.

To prune blackberries, first you have to know blackberries.

Blackberries fruit on second-year growth.  That’s known as a biennial fruiting habit.  Lovely fancy terminology.  More of that to come.  Don’t be intimidated by the words.  It just means that, like many flowers, such as Sweet William, you plant it one year, it puts out green leafy growth only.  The next year, it will flower, and in the case of the blackberry, it will make blackberries.  You can tell first year growth (called primocanes–prim0=first, see?) from second year growth (called floricanes–flori=flower, easy!) by their appearance.  Primocanes look fresh, green, and new, with lots of tender growth at the tips, (and no flowers or fruit) throughout the growing season.  Like this:

In this next photo, compare the primocane on the right to the floricane on the left.  The floricane, in addition to the obvious flowers, has darker, more mature leaves here at the tip compared to the primocane.

Now you know your floricanes from your primocanes, let’s talk about pruning.

The most basic, pruning 101 is removing floricanes after fruiting is over.  They will not bear fruit again, and removing them is crucial to keeping your blackberry bushes from looking like a celebrity mugshot hairdo.  Those old canes will hamper new growth, encourage disease, and make harvesting next year’s crop more difficult.  Here’s a spent floricane:

Follow it down to the ground, cut it off at the crown (where it emerges from the ground), pull it out (wear heavy gloves if yours have thorns) and discard it. Keep going until you’ve pruned them all out.  Done.  Easy.

The second type of blackberry pruning is known as tipping.  This is done throughout the growing season.  Blackberry canes want to send out long runners, several feet long, at the expense of branching growth.  This makes your bushes look more like giant spiders than shrubs.  This characteristic is called apical dominance.  The tip (or terminal bud) of those long canes contains a hormone called auxin which actually inhibits the growth of the lateral (or side) branches.  Naughty terminal bud.  What we want is lots of lateral growth and thicker canes for more places for blooms and berries and stronger canes to support those big, juicy berries.

So what we do is cut off those naughty terminal buds so the canes will be able to branch out, get stout, and produce more fruit.  In this photo I’m showing you some of the lateral shoots that will grow and beef up the cane once the tip is removed from the end of the cane they are on:

See the little leaves trying to grow?  In the next photo, check out the lateral growth that has begun on this cane which was pruned a few days ago.  This is what we want.

Keep your canes trimmed back to from 24 to 48 inches long, depending on how compact you want your blackberry bushes to be.  And once those lateral branches that you’ve encouraged to grow get over 18 inches long, tip them back, too.

So now you know how to have tidy, productive blackberries, clear out some space in the pantry for some of this jam.



{ 21 comments… read them below or add one }

1 Matt J July 22, 2011

Thanks for the info! My creekside blackberries are gonna get a haircut this year :)

2 Jessie July 22, 2011

You mean running them over with the lawnmower is not the correct way to prune them? ;) haha

Thank you for the tutorial, that actually helped a lot!

3 mike July 31, 2011

I want to use the black berry bush not only for fruit but for security purpose but I need to keep them under strong control. Can YOU HELP WITH ADVICE

4 Devo! August 24, 2012

Excellent tutorial. Planted my BB bush two years ago, was uninformed and disappointed after the first year, and shocked when it exploded into 15ft high/long canes this year! Enjoyed the berries i did get, but was in the dark on how to control the plant. Looking forward to a more controlled, productive, and delicious third year. Thanks again.

5 Devo! August 25, 2012

Follow up questions, advice appreciated. Now that i’ve cut back the spent floricanes what do i do with the long, unpruned primocanes from this year? Should i just let them go and begin tipping next year, or is there some pruning that can be done? I’m in zone 4a-ish so there’s only a month or two of green season left. Will this years large primocanes die back to the ground or will i be stuck with these gangly monsters for one more year?

6 Daisy August 25, 2012

Devo!–I’m in a much more temperate zone (7b/8a) and my primocanes will keep growing for a while and cruise through the winter unscathed. SO, I hesitate to advise you up in 4a. Are you thinking that your primocanes will be winter killed as a matter of course or because they are so long?

7 Devo! August 25, 2012

As a byproduct of the cold weather.
I wonder if i have the variety this guy is describing >>>http://www.youtube.com/watch?v=kl0uSW4_Dqw<<&lt;. When trimming out the floricanes yesterday i (think i) stumbled upon the tiny first year canes that were clearly dead, brittle little 1-2ft brown sticks woven through the chain link fence the plant is near. Clearly those did not return for a second year, but also the huge canes this year (three bore fruit, five did not) were not present at all last year, so i'm slightly baffled.

8 Daisy August 26, 2012

Devo!–Interesting. It makes sense the nurseries in your region would stock primocane fruiting varieties, so maybe that’s what you have. You mentioned you planted them two years ago, in which case it’s possible they’re prime-jim or prime-jan because they came out in 2004. If you decide yours are floricane-fruiting, in the future try a method of tipping called “soft-tipping”, which means removing 1-2 in. from the tip of the canes once the canes are about 3 feet long. I’m not sure what to tell you to do this year not knowing what kind they are but it doesn’t sound like you can go horribly wrong. Blackberries are so vigorous they will survive most anything.

9 Sarah September 29, 2012

Most helpful and useful info on this I found. Thank you!!

10 Sharon Gullikson February 11, 2013

Thanks for the info. What I’m still not clean is the last 2 photos. Where do I cut? I live in Orange County,CA. I already trimmed back my bushes fairly severely, and THEN looked online. Woops. I may not get much fruit this year. So I want to trim them properly from now on, but am not clear. Will you be putting diagrams or doctored photos on? Also, how do you keep track of which branches have already fruited (my flower parts fall off eventually, so the evidence disappears)? Do you mark the branches, or trim them back as soon as you see that all of the berries have been picked? Thanks a lot.

11 Daisy February 11, 2013

Sharon Gullikson–You want to tip your runners after they are 2-4 feet long. 2 feet if you want compact bushes, longer if you want them to get bigger. Cut just after a node (where a lateral will sprout from). It is easy to see which have fruited because they look old and tired and the new growth is bright and young and green. You won’t need to mark them, you will soon learn which is which. It’s easier than it looks once you get started, I promise!

12 Sharon Gullikson February 11, 2013

Thanks Daisy. I think that I get it now. Hopefully I’ll still get a good crop of fruit this year, even though I cut them way back. At least now I know what to do from now on…
Thanks again!

13 Kurt L. June 9, 2013

Please help… I’m more confused than ever. I have some nice looking two-year plants (thornless) that are exploding with flowers off the lateral shoots created from “tipping”. So… once these lateral (floricanes?) are done, do I prune the actual original primocane at the ground (after the 20 or so laterals are done of course!) or just the floricane back to the primocane and keep the primocane?

Thanks!

14 Daisy June 9, 2013

Kurt L.–Think of it this way: after it blooms and produces fruit, remove it to the ground. That whole thing is a floricane by definition. Nomenclature follows function here. Does this help?

15 Kurt L. June 10, 2013

Yes, thank you.

16 Ron September 15, 2013

What about first year plants? We are in zone 5 and I set out some young thornless Chesters back in the spring. It’s now mid September and those babies are off to the moon!! They have lots of runners ranging from 1-20 ft.. I have not done any pruning thus far. So now do I just wait until after harvest the second year ? Thanks….

17 Daisy September 15, 2013

Ron–You still want to tip prune them to encourage branching, ideally throughout the growing season. I don’t know what to recommend this time of year, but if those 20 footers are grabbing you as you go by I would give them a haircut. Doesn’t seem like growth will be a problem and they will make it up eventually.

18 George February 16, 2014

Hi. I have a huge older thornless blackberry bush on the back side of my property still here from the previous owners. It’s probably 8′ tall and just as wide but produces very few berries. I’m assuming because it has been left to grow wild without pruning. I honestly have no clue which of the many canes are from what year, etc….. My question is can I prune the whole bush back severely, like maybe to three foot canes or so, prune the lateral shoots and maybe then prune selectively this year when I can get an idea of which cane is doing what? I don’t want to kill the bush but I would like to get it under control or pull it and start fresh in that area. Thanks in advance for any advice. :)

19 Daisy February 17, 2014

George–That sounds like a good solution. After you cut everything back to a manageable size, you’ll probably be able to tell more about what’s what, too.

20 Berry Nice May 30, 2014

I have a second-year ‘Navajo’ BB (upright thornless type) that did produce a little ‘sample crop’ of fruit last season and its first ‘real’ crop of lovely big berries this year. Mine seemed to be doing its thing quite a bit earlier than most of the other BB plants around here, and my harvest time is almost done. It is shooting up just one new P-cane as I type, which is now about 20″ tall. I’ll be cutting the ‘retired’ canes back as soon as I get the last berries off of them. Once I cut out the retired F-canes, will I start to see more P-canes?

21 Daisy May 30, 2014

Berry Nice–Yes, I should think so, although I’m less familiar with thornless types at this point (planted some this year). The fact you have only one, but you do have one, indicates to me it’s a precursor of more to come but that since this is only its second year it may take a bit longer before you have new primocanes bursting out everywhere.

Leave a Comment

Previous post:

Next post: