I'm in Raleigh and by far the best producer for me is 'Heritage'. In a mild year I can get far more berries than I can eat off of both crops and I have picked berries almost up to Christmas. It is the worst about catching every disease out there and the berries don't have the best flavor fresh but cooked for jelly or as a sauce it taste just like any other red raspberry. I have had 'September' and 'Caroline' and 'Dormand Red', all have struggled during high heat summers. I have never picked enough berries off of them to compare the flavors. I think there is only one tiny stem of 'September' up this year in that row. It looks like the past summers of high heat and drought along with this recent hard winter have done a lot of them in. I do have a few 'Mandarin' which were developed here at NC State years ago. They are weak plants, prone to virus and very hard to propagate. I have them in half day sun and they seem happy but not as robust as Heritage in full sun. I just bought some 'Polka' and 'Josephine' to try in the shade with the 'Mandarin's'. They are big enough to fruit this year so I'll know more later. I had both 'Kiwi Gold' and 'Fall Gold' and both suffered this winter - died all the way back to the ground. It will be a month before I see how alive they are. For Blacks I am growing 'Jewel' this year but my plant is tiny. I have grown them before in shade and they did great but you get a lot of plant for few berries. With more light they may perform better but you have to either prune them all the time or be prepared to have a large plant in the yard. Growers trying to grow reds in this area do all the tricks to keep them cool during the summer - shade cloths, white fabric mulch to reflect heat away from the ground, lots of watering, etc. I was told 'Nantahala' wouldn't do well here (by the person that bred them), they were designed for the mountains. Good Luck.

Gmshack - I have read of using both plastic and Agribon, but haven't gotten around to the plastic part yet. There are two main issues with overwintering and some studies suggest that dehydration is a bigger problem than cold tolerance in cold climates. I used drew 51's technique of Wilt Stop this fall, so we will see if it prevented desiccation. I also used two layers of Agribon. I find that one layer does not provide the protection that the company claims. I start covering mine around late August when our first frost hit. This is both to protect berries and reduce temperature shock from early season frosts. In the spring, I am leaving the Agribon on for a few weeks. This next spring I will leave it on until each variety begins to flower. This substantially increases growth for me (in our very cool Mays) and hastens flowering by a few weeks. I do remove it on days with temps over 70F. Desiccation is a real problem for me since our ground is frozen solid for at least 6 months out of the year. Add to this that preliminary probing this last summer suggested that blackberry roots up here only extend 3 or 4 inches into the ground (it is too cold below that, with an average annual temperature at 3 ft of around 31F). In this situation I believe that the roots cannot take up water to replace what the canes transpire during the winter and they end up desiccating and dying way back (from 8-10 ft long to about 2 ft). We will see. As far as the weed block, it will probably not increase the soil temperature as much as removing it. I'm not sure of this as I don't have experience with it in the Lower 48. Up here, it must be removed in the spring for about 4 weeks to allow the soil to thaw and then reapplied. Your soil is already thawed and substantially warmer, so you shouldn't have to do this. What I think I get from weed block is increased heat above it = though I have no data to show that. I just know that of two Wild Treasure plants I have (that are one year different in age), the one grown over weed block is much more vigorous than the other. I trellised the very vigorous one last year and it continued to grow strong even though most of the canes were not directly lying on the weed block. A study at Oregon State Univ. also supports this. However, Wild Treasure is a crown-forming variety, not a spreading variety like the ones you have, so covering around it with weed block is a simple process. I do not grow primocane blackberries because the season is too short and there is insufficient heat. Everyone of them has died completely. I have one Triple Crown left and a very wimpy (it grew 2 whole inches this year) Chester. Neither has canes that survive - but then I have not covered them. I am guessing that if your TC canes survive and leaf out, but don't flower, that the flower buds are damaged by the cold. Flower buds on many plants are much less tolerant of cold than non-flowering buds. I have two varieties of erect blackberries that I am trialing that might be of interest to you. They are Nelson and Stenulson. Stenulson has been in the ground for several years, but moose have browsed it down each year and voles girdled anything that was left. Thus, I don't have an idea of its ripening season, but it is likely too late for me. It grows pretty well here and is spreading (unlike TC and Chester which only get smaller each year). I have had a few green canes survive the winter and start to leaf out and then die because they were girdled by voles at the base, so it is pretty hardy (though these were covered by snow mid-winter, when air temps dropped as low as -35F). I just got Nelson last year and it actually flowered earlier than any other erect I have. Its berries are somewhat frost tolerant, as well, to at least 28F. It still did not ripen early enough, but it was in a pot and not established. The timing could change in the future, especially if I put an Agribon "sack" over it early in the season. Both of these are thorny. I got Balsor's Hardy Black from the USDA germ plasm repository this fall, but it failed to root before it rotted. This is another possibility, but it is not commercially available in the US. Happy New Year!

Nice to be able to report good news here, my recent plantings have really taken off, Autumn Britten this years bare root plant from Raintree was planted at the end of April and it's a beast of a plant with several long canes with lot's of berries, def needs support as it grows up and out at the same time.....every berry plant has it's own personalty.....my Josephine has canes at least 7 feet long and supported by plastic wire on my trellis system, very heavy from weight of future berries and many......Nantahala is finally putting out fruit buds now, nothing from Double Gold or Crimson Giant but very healthy vigorous growth, Prelude another spring planting has several canes about 7 feet tall needing a mini trellis because of all the future berries and lot's, this is suppose to be a summer variety with bonus Fall Crop but mine has exploded growthwise and it has berries all over the place, not just the tips and it's still growing a great addition....both my Fall Gold and Kiwi Gold spring plantings are doing amazing with several healthy canes and suckers coming up, i may have an overlapping summer/Fall harvest on one Kiwi gold as the Fall crop is almost ready and summer crop is still not done, that's a great plant too and very tasty...,My Polka spring plantings are almost ready to deliver a small Fall Crop as the plants didn't grow all that much but healthy....Caroline failed to fruit as a late spring planting, neither did Jaclyn or my Heritage, but i'm told it's normal for a young plant not to fruit for 2 years. Here's a pic of my Autumn Britten's Fall Crop .... my one plant which is all need of this variety as it's very vigorous and has many berries on the top third of it's canes and then some this year is about experimenting with growth characteristics, productivity,disease resistance, root rot & how much suckering each variety offers and most importantly TASTE ! Some may have to go if i don't like Nice berries Autumn Britten here

I keep hearing good things about Nantahala but so far I haven't stumbled upon one (even when visiting Asheville nurseries, which is odd, it should be popular there). All the red varieties are going to be tricky here. Even when planted in the shade they eventually catch some sort of disease and go downhill. Most of the 'Mandarin' that exists is diseased - mine don't show it but I imagine their days are numbered. Even 'Heritage' eventually catches something. But, keep in mind that most of them propagate easily and grow fast when they are happy so you can just keep planting them while you yank out the dying ones. Black raspberries like 'Jewel' do well here and don't seem to need the shade to survive. The flavor is different and the production seems lower than the reds. I grew 'Kiwi Gold' and 'Anna' (I think that was the name) and both eventually died but sometimes I'll find one tiny baby plant poking its nose up out of the weeds. They produced fine for the first year or so before getting sick. The flavor is different, more sweet than berry flavored. Blueberries need a bit of soil prep to keep them happy but once you have them going they will be your biggest producer. Blackberries can be easy but they make much bigger plants so you have to set aside some room for them.