Try www.mcfayden.com

You want to check. Any cold hardy blackberries I've looked at were Zone 4 or higher. Of course that doesn't stop Home Depot and friends from selling them in colder zones. The successful zone 3 growers bury the canes for the winter.

Thanks for the link. I saw that most were for zone 5 or higher but that there were some for zone 4. Some you mow off at ground level after frost so was wondering about them, Michigan U developed them I believe. I had a link that was great but alas I deleted it...
Thanks, will go check out the link provided.

As far as I know there is really not much out there or none for zone 3.
I do believe fruits will set only on old wood, so cutting back wouldn't work.

Konrad

Here's a link to a video on some research on primocane blackberries. But these are from Arkansas and they only fruit late in the fall of the first year's growth, so I'm certain they wouldn't fruit on first year wood in cold climates... at best they would be like regular floricane blackberries in cold regions:

http://www.youtube.com/watch?v=Dq3OT1BbqBs

Thanks Don for the link
You're right, this new one doesn't sound good,....in video, it's October
and just starting to get red. I'm not impressed at all with that little fruit set on this HUGE plant,... .some canes are just flowering now. The harvest of regular berries, [fruiting on old wood] was done a while back and finished.

I guess for long seasons down south it makes sense, you can harvest a longer period, from summer till fall. Still, not a very productive plant
here!

Konrad

Never had any luck with blackberries here in SC Alaska, Zone 4. Anyone had any success with them in zone 4?

limeres, are you asking about thornless specifically, or blackberries in general? Blackberries (wild) do fine here. Trust me, -35F happens here, and -20F isn't unusual. So, yes! Blackberries grow in Zone 4 (and 3).

The odd years here we can get -49F in zone 3.

Wow, Konrad--better you than us, LOL! Your record low is lower than our record low. But that doesn't affect limeres, who seems to be in Oregon.

Seeing as limeres advises he is Z3, i don't believe a thornless blackberry will do. A hardy wild type probably will.

Chester blackberries are the hardiest thornless variety
zone 4 with some success in zone 3
konrad is right they are floricanes, fruit on last years wood
i just ordered some for this year
and may try tying the canes down like grapes in the double guyot system
then they get a good snow covering for insulation

I've played with a couple of Chester Thornless blackberries, starting in 2009 when I put them in as packaged plants from Home Depot. No production the first year (none was expected). I laid the canes down in the fall and one of two plants survived to spring 2010, including much of its cane from the previous year. That plant set 30 or 40 berries in summer 2010, but only a single berry ripened before frost took the fruit out around mid to late September. 2010 was a very cold summer here though, so I'm hopefull of better results in year with a warmer summer.

Okay, here's the followup in Spring 2011. Just uncovered the canes today (Chester Thornless), they are green, even have some of last year's green leaves, so weird. I'm thinking I should cover them with a thin sheet for awhile so they don't sunburn, as they haven't seen any light for over 5 months. Some pics:

The vine planted in spring 2009. The cane is green and about 9 or 10 feet long. Gets a bit lost with the grapes behind it.

The vines planted in Spring 2010:

So strange these leaves are still green???

Good snow cover you had for sure, I had this one year, the following year the cane was dad, it wasn't chester, a BC seedling, hopefully your's fair better. Looks like your'e in the city,..usually add one more zone in a sheltered spot.

Don and others.... how is your Chester doing this year?
I put one in last year, no cane survived the winter. Do they ever flower on a new cane?
Guess not because there is no sign.
How long of a surviving can you need for flowering?

unimpressive growth on the chester's,
even when tied down
removed them last year and planted grapes in their place

zone 3, maybe in a greenhouse,
or tie the canes together and wrap in burlap for the winter

but that is quite the input, unless you absolutely love the berries

there is a way to get higher zoned grapes to ripen in lower zones,
and this could be used for blackberries
- first is tie them down and keep them snow covered/heavily mulched
- then as the canes/spurs grow you stake them along the ground towards the south
- on the ground is a heavily weed matted area with a goodly amount of gravel
- this will warm them earlier in the morning, and they stay warmer longer in the evening, allowing the fruit to ripen and helping the growth/hardening off of the replacement canes/spurs

Konrad, no they don't flower on new canes, only on second-year growth. There are primocane blackberries, but they don't fruit until Fall even in the deep south USA, so no value here.

I have 2 Chesters, both came through last winter nicely. Well, nicely for here, which means the canes died back severely but the centre of the plants survived and are growing well. But that's better than last year when only the canes on one of the two plants survived and produced fruit (over 500 berries!) -- both plants then grew new canes which made it through winter 2012/13.

My plants are flowering heavily now and setting lots of berries. They usually don't start ripening until late August, about the time the raspberries are finishing up.

A few pics of one of the plants, not the greatest since I took them last night after sunset, but you get the idea...

I've tried to grow it all in zone 2 and failed a lot. Tried blackberries a few times. The season is too short and the frost starts at the end of August. The first year berries were just starting to ripen. Despite the fact that it only got to -35, they died. My biggest enemy is the short growing season that doesn't allow enough time for new wood to harden. My Valiant grapes died after a couple good years of growth despite the temperature being well within their tolerance..

Granola, I know what you mean about the short season for ripening. This is the 4th year my canes have been fruiting size. In 2010, my one young plant produced one berry before frost took out the 30-40 more that were developing. In 2011 I had 2 fruiting plants and got over 400 berries in a long growing season. In 2012 only one plant fruited but gave over 500 berries in another long, hot summer. This year I have 2 plants producing fruit again, and quite heavily, but I'll need another long season to ripen everything, and that's always iffy around here.

On the positive side, I do believe that as the plants get better established over the years, not only do they set a heavier crop, but they also set it slightly earlier. We aren't talking huge amounts of time here, but maybe a week earlier. I think this year my plants are at the same stage as last year, but this July we are running 1 degree below average July temperatures, whereas last year we had a very hot July.

Thank you all!
Don, you're at least one zone warmer then my plants out of town.
I'll take it out next year if it doesn't smarten up.

But..I put in a Balsors, [thorns] and this one is flowering on new wood,..will see if they ripen,...agree with short season,
cant benefit from it's full potential.
Any have grown this one?

This year I bought some seedlings out of Montreal, they claim to be hardy for Alberta,..will see.