+13 degrees is said to be the magic number for varieties such as Triple Crown; below this and there can be bud or cane damage or cane death, especially with early or late season chill. That is why many zone 5 people try to lay the canes down and cover the whole works. Hard to do with vigorous TCs.

I hope it hasn't already gotten too cold here, it was supposedly 17 here the other night. But the past couple of years I've laid the canes down on the ground and covered with a couple layers of burlap and they did well.

I'm going to try Bonide's Wilt Stop, as the canes dry out, the roots are non functional, so the canes dehydrate. I cover most of mine as much as possible, but triple crown is semi-erect. The canes will break if I try to lay them down.
I wish I already put the stuff on, they need it! Now I have to wait till this cold front breaks. The crown will survive, but the canes might not. I'm going to keep trying things till I figure out a way. I thought of using row cover and then insulating the cover with leaves. It gives me a surface to work with. Also easy to uncover in the spring.

Burlap, never thought about that, I may try that instead, thanks for the info! Well I'll still use the wilt stop, but I want those berries! Great tasting!

This post was edited by Drew51 on Thu, Nov 20, 14 at 0:32

I think 13F is the lower limit for western trailing varieties, Triple crown can go a lot lower. You can go to least 0 without bud or cane damage. -5F is where you would start to see damage occurring. Mine hit -7F last winter, uncovered, and I had about 30% loss of canes on mine. I still had good production this year on TC. You can read more about winter protection and Triple Crown's lower limits in the "Rowcovers Improve Winter Survival.." article. I used these methods in the article to grow my western trailing varieties.

Wind protection would be beneficial.

Here is a link that might be useful: Rowcovers Improve Winter Survival...

Well it looks like row covers or burlap would work. Row covers could be used in the spring over other crops like melons that like it warm. Burlap no, Cost is about the same. I guess either would work as the plants do not need light in the winter, so burlap is fine. As long as the ice age continues I will be using both! I'm going to try both. See if one is better than the other.

They don't exactly lay flat on the ground. I cut them down and they loop to about 2 ft high, so it's not like I could put mulch on them.
Any idea where I can find burlap? Would plastic work? I know I can find that. Seems like that will keep the frost off but how does it help with the cold?

Plastic will cause mold. Home Depot has burlap. Some row covers are 5 feet wide, You should be able to cover with that. The burlap is 3 feet wide. I just want to cover the bottom of my row as I can't keep leaves on it. I want it to keep leaves in place too. Here Boysenberry and Wyeberry are completely coverred with leaves, except edges (why I need something else). The semi erect at the end is chester. I will throw burlap or row cover over it. And run row or burlap along the edges of the bed to tuck in all canes. Row cover is good because it keeps heat in, so they do not get cold. Burlap does not. That is a doubled edged sword, the freezing and thawing is what you want to avoid. The row cover when mild might be detrimental allowing plants to thaw quicker from the sun. So burlap is better to avoid excess heat and thaw to happen. The row cover can only increase a couple degrees, but might be enough to keep a cultivar alive. I think though wind, drying, freeze -thaw cycles are more deadly. So in that sense burlap may be better. Both let water through and air.You should use 2 layers at least of burlap, so in that sense it's more expensive.
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Here is my Natchez, even with burlap or row this is going to be hard to cover. I broke a couple canes trying to move them. I may tie them to the fence and cover fence. I have a fence and trellis here. Behind it are Columbia Star, Loch Ness, and Black Diamond covered in leaves.
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"+13 degrees is said to be the magic number for varieties such as Triple Crown...."

I was scared. I think even the Boysenberry says it is hardy to Zone 6. And Zone 6 dips below 0 F several times each winter.

In general, TC should be ok with Z6. But Z5 can have damages. I think that was what happened to Drew....

You will see conflicting information on a lot of varieties. I'm not sure any blackberries, except for perhaps wild varieties native to zones lower than 6, will be hardy past -10F.

I had boysenberries (thorny) planted in the ground and in protected pots last year and they are not hardy to zone 6a or 6b, according to the latest hardiness zone charts. Zone 7a, with a low end range of 5F would probably be the lowest you can go without getting bud and cane damage. The advantage for boysenberries is that since they are trailing, you can cover them effectively and protect them several zones lower.

The further the blackberry cane extends out of the ground, the less thermal benefit it will receive from the ground temperature, even if you cover it. Semi-erect (Chester and TC) and erect (Apache, Ouachita) varieties won't benefit from covering them other than the benefit from wind protection.

I can confirm that Triple Crown can handle much colder than 13 degrees. I've had Triple Crown in zone 6 in Pennsylvania for several years, and even after last winter, which was brutal compared to the previous 10 years, the plants were fine.

Here's what I use to cover my plants. The Agribon-50 provides cold protection but also allows light through to allow for early ripening.

Here is a link that might be useful: Agribon AG-50

Well I'm in zone 6 and last winter all the canes, right to the ground died on Triple Crown.
J that row cover is almost 1/2 the price on Amazon free shipping with large order.

Drew,

Didn't you mention that your temps fell below zone 6a minimums...(e.g.-10F)? The closer you can get your plants to the ground and seal in the ground temp, the better they will be. My TC's grow upwards 4+ ft before they start running (e.g trailing). At that distance from the ground, you can't retain the ground thermals.

The row cover only helps retain the thermal energy that is present. Once you break contact with the ground, you will generally get the air temps which are much lower. That's why the crown survives while the canes do not.

I'm trying cardboard under the row cover to reduce the impact of conductive heat loss. My theory is that because corrugated cardboard has air pockets, it will lessen the transfer of cold temps through the direct contact of the cane with the row cover. I feel more confident of my theory after a couple of glasses of wine.

Yep, I was mis-quoting an OSU report about the +13 degrees. Cranking my head sideways to read the tables may have affected the brain! But most everyone in zone 5, where the OP is from, takes extra winter measures for TC.

The +13-prone Rubus ursinus, our local trailing native, the source of many flavorful hybrids, occurs on the west (warm) side of the Cascade Mountains, at lower elevations.

Yeah we got down to -14. it was cold last winter! I see the drying as a big problem. Listening to experts it is the drying that kills a lot during the winter. So even if not warm from the ground, protected from the drying winds may help. I still need to cover my trailing so will try it anyway. Our winters are not always that cold, so just a matter I guess of waiting it out till winter temps are more normal, although that could take 10 years, so maybe pull the plant next year if it happens again.
The reason I think drying is improtant is because boysenberry, tayberry and wyeberry survived the -14 degrees too. The only cover the boysenberry had was from grass my dog kicked up on it. And that was enough to get some fruit this year from the stubs that survived, the parts covered with grass from the dog. Near the ground it might have been warmer, maybe -12! Point is, it was way beyond it's kill temp, yet it did not die. I think because it did not dry out. We had 2 other days where it hit -10. 13 days were below zero. Most ever in my lifetime. The Loganberry did die. All others made it. Natchez had one cane with no damage.
If they do make it this year, next summer I'm going to have hundreds of berries. Growth this year was fantastic!

So will the semi-erect triple crown canes will break off if layed down (remember we have heavy snow) or not? I'm thinking some will but it's probably worth trying the burlap technique. So I'm torn, which will produce less damage, laying them down with heavy snow on top or leaving them up with frost damage?

Winter damage to TC and other thornless varieties I've tried like Navaho is not predictable based on temps alone. I believe it is a variable number probably based on multiple factors, including the state of the plants going into winter, the relative state of hardening off when cold hits, wind exposure and so forth.

The canes do get harmful winter damage fairly often in Z6, in my experience, including killing them to the ground some winters. I bet burlap over the top right to the ground would be helpful even here, not just by reducing wind, but also by holding heat from the ground a bit for the canes.

Be sure to bait out voles (mice) if you create any kind of shelter. I've seen them girdled in bad snow winters.

So will the semi-erect triple crown canes will break off if layed down (remember we have heavy snow) or not?

Well just be careful I got them down some but lost one as it broke on me. It can be done. It didn't matter the plant has canes all over the place. The plant is worth the fuss, it produces some excellent berries.

So I can tie burlap to the trellis or do you think it's better to lay the vines down and put the bulap with say leaves in top. I could use a few bricks and make a small hut with every few feet with the burlap on top to keep the snow from breaking the canes. Or just cover the trellis???

If you can get them on the ground that is better. If not tie to trellis. I'm just using cothes pins and for the ground 6 inch garden staples. They sell them everywhere. Some cultivars like Natchez is not going on the ground. You can see a photo of it in this thread, that baby is very upright! Triple crown is not as upright but near the base it's going to be hard to get it down. I would use leaves if you can, the more we protect the better. You can't overprotect them.

Perhaps you could train them to grow at a slant so they could be more easily lain down in winter. I've never grown blackberries, so don't know how easy that would be. Might look a little strange, but better than no berries at all due to dead canes.
Northwoodswis

Northwoods, you could do that, that would help. At least point them in the right direction. The darn things grow fast though. Awesome plants.