milehighgirl,

I planted triple crown blackberries in pots in 2012. Drug them into an unheated workshop for the winter of 2012-2013. The leaves never turned brown. They were healthy and fruited well in 2013.

I am in zone 5A. Blackberries are iffy in my zone. In addition to those triple crowns, I am overwintering one year thorny boysenberries in pots indoors. I have Siskiyou on order. I'd like to plant them in the ground and cover for the winter in a manor similar to your approach. But I'm concerned that the my winters are too cold. Your results would be very helpful. Please let us know how they do.

Thanks.

lsoh,

I think it's sort of a windfall for me. We have had temps in -20's so far this winter and I was shocked and overjoyed when I saw how they were doing. I thought my blackberry experiment might be a waste but this give real hope!!!! And it was so easy and free, save the cost of a large trash bag!

I think that some have problems because the plants are thawing and freezing multiple times. I too have had cold temps to -14. Mine are exposed, I see some tip die back, like an inch. But otherwise they look good. Some of the canes are even green. No dieback on raspberries at all.
No dieback on some of the blackberries. More info when spring comes. Which is about 52 days or something. This is the worst, after a couple weeks it should start to warm up.

I wouldn't worry too much about it. Blackberries don't seem to go dormant like a tree would. Mine hold on to some leaves all winter, even when it is very cold like it has been this year. As long as they make it through the winter they should produce fine.

Leaf color is not an indicator of dormancy with blackberries. Varieties such as TC lose leaves closest to the ground and the farther up the cane you go, the more leaves hang on and remain green.

Dormancy is when the canes or laterals stop growing in length.

Okay, I know they aren't growing any but I am sure glad they aren't dead either. Thank you!

No leaves can stay green here, not at -14 degrees. Some though, very brown leaves are still attached.

The brown, frozen blackberry leaves are an indication of general plant cold-hardiness rather than any state of dormancy.

I am curious if your brown attached leaves are ones further up the canes?

"I am curious if your brown attached leaves are ones further up the canes?"

Seems to have leaves all over. Here is a photo of three cultivars taken 2013 12 19.
From left to right Natchez, Navaho, Triple Crown to the left of the 4x4 in the center. The Triple Crown has canes going to the right of the 4x4 and also down another trellis you can't see to the left and behind. it's bigger than it looks.
The 3 or 4 canes to the right of the 4x4 are Tripe Crown.
Just right of the 4x4 on the ground a bundle of chicken wire is holding leaves over a Wyeberry. It was extremely small and only producing 2 foot canes. They are buried under leaves, and under the snow for protection. One cane was left exposed. The next plant to the right is Boysenberry and it is thinner, but has leaves. To the right of that, and at the end of the photo is Chester. Again to the far left is Natchez, you can only see some of it in the photo, it also is a huge plant!
All of these were planted last spring, so it's the first winter.

This post was edited by Drew51 on Wed, Jan 29, 14 at 12:53

Drew51,

Thanks for the photo. I can't imagine that the leaves would still be attached. I won't be able to leave mine on a trellis all winter here in Denver but it's good to know what to expect. Yours put on a lot more growth than mine did but I had mine potted for most of the summer.

Milehigh,

Well two other plants are to the right of this photo it is a low area. They look bad and I don't expect them to survive. They hardly grew.If they die, i'm going to put a raised bed there to solve the low area problem. The canes look like they are on a fence, but the fence is behnd them. They are trellised. Anyway looking at that shed, and the fence line you can see it becomes lower left to right.
They are quite messy looking. And next year I expect even more growth. But they produce berries, will have flowers, hopefully will look better in the summer. Having erect, semi-erect and trailing plants, it's not easy to trellis them in any kind of neat way. Then again I have no excuses for how messy my desk is either! As long as they produce anybody who sees them won't mind when I put fresh fruit under their nose.

I prepped the ground heavily with compost and mulch. More compost and mulch will go on in the spring. Plus organic fertilizer.

Here's another photo from the other side. You can see the trellis splits left and right of where I'm standing.

Here's a photo from the back to the front. The trellis with the Natchez, Navaho and TC is hard to see (at the end, to the left). These last two photos were taken on 2014 01 14
The closer plant is a Chester. i need to prune off some of those weaker canes. BTW my dog patrolling the yard made all those tracks in the snow.

This post was edited by Drew51 on Wed, Jan 29, 14 at 12:52

Thanks for the photos and leaf info. These plants probably behave differently in various climates--the cold may disrupt the dead-leaf progression that happens in my mild winters.

At the other extreme are raspberry types. My black-caps never hold onto a single leaf and the Logans (that are half-raspberry) have a few leaves left on the cane tips.

Examples of milder-winter caneberry leaf patterns:
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^ Loganberry (coiled at left) and TC bare base and leafed tips
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^Black-caps with no leaves

Nice set up Larry! I wish I could define the area better like you have done. Maybe in the future I can. Canes are nice and neatly wrapped too. I let mine get wildly long and ton's of laterals. probably too many. I will cut them back more in March after the severe weather passes. We are expecting 4 more inches of snow by Saturday (sigh).

larry_gene,

Space is at a premium for me. I'm thinking of trying to shoehorn in some trailing blackberries. I would loop them around as you do and try to keep them 2 dimensional. How deep (front to back) does your foliage get?

Do you tip your trailing blackberries? If so, when?

Just curious, there seems to be some wire fencing on the ground under your blackberries. What's the purpose?

Thanks.

My raspberries (Triple Crown and Chester thornless) look just like Drew's, with the brown leaves hanging on. I got mine from my church, where they're only covered by snow (about 12" deep) during our 5a winters. They're very productive at church even after cold winters. Chester thornless seems to be a stronger grower and more productive than the Triple Crown, but I haven't quantified it.

@Drew: You may be wise in allowing overgrowth and then pruning back after any winterkill. In October or November I prune off up to half of all lateral growth as there is typically zero winter loss in zone 8b.

@lsoh: The thickness (front to back) of the leafed and fruiting row for Logan, black diamond, and black-caps is a foot or less. Black diamond has very short fruiting spurs; the others can be a foot. I do not tip the trailers as I don't have that many trailing canes. They can be looped and threaded anywhere on the trellis. Note that my trellis requires no guying as all steel posts are connected on top with cedar in both directions, down-row and between rows. Saves space and maintaining wire tension is easy. Row spacing is 4 feet. Repeatedly bumping head on 5-foot-from-ground cedars is optional--but the pipe insulator foam does come in handy.

The ground fencing: Prevents squirrel cratering

larry_gene,

Thanks. That was helpful.

Yes it was helpful! Your trellis is impressive! You could grow water melons vertically off that baby!! My trellis has wire tension cranks spliced in to tighten wires. This trellis is like a double trellis, 2 wires on either side at 3 feet and 5 feet. Local pine hay makes a nice mulch in the bed.
Those wires are between poles that are 24 feet apart. So some kind of wire tension device is needed. Grape trellis wire is used here, I forget the diameter? Quite thick! I also have a thinner wire I will use once this roll runs out. It's a little too thick. I'm putting one more trellis up next spring. I also have two others not seen in any of these photos.

24 feet is quite a span to tense wires. For my 10-foot rows I am simply using eyebolts that have about 2" of thread, and rotating the nut further up the threads increases tension. That wouldn't work for you, there is more than 2" of potential slack in those long wires.

Last 2 years were mild with 7F being the lowest temperature but this winter we have so far had 6 different days with a low of -5F or better. Spot checks on covered and exposed blackberries show some cane damage and some surprises. The boysenberries seem to be holding up pretty well, while several trailing blackberries I had been trying to overwinter in pots seem less well. Of the exposed blackberries, only the Prime Ark 45's seem like there is any significant cane die off. Winter is not over yet.. so we will see.

I thought I ought to post an update. My blackberries made it through unscathed. I don't know how I will do it next year because they will be longer vines, but rolling them up and putting a large trash bag full of leaves on them did the trick. It's the easiest winter protection I could ever imagine and I stumbled on it by sheer luck. We got to -15 here in December.

Next year I'll be covering with leaves too, I covered one plant and it looks great!