I've been eyeing green blackberries for weeks and they are finally starting to ripen. My berries are in the community garden plot. I have one "Prime Ark Freedom" (survived from last year) and two "Chester" (new this year). Both are thornless varieties.
The lone Prime Ark bush that survived the 2016 Vole Attack froze back to the ground, losing the floricanes, but put out very robust new primocanes. The big deal about Prime Ark is that even if you lose the spring floricane crop, you can still get a nice primocane crop in the fall. Or lucky people can get two crops.
The Prime Ark berries are bit bigger than thumb size and firm. Some have a strange split-fruit thing going on but I'm hoping that will go away by next year. I had to start picking them a bit early because I lost a few to the critters. The flavor is pretty tart but that could be because they had to finish ripening indoors.
The Chester bushes are new this year and got a late start because voles or rabbits were eating the new shoots. They are decidedly smaller than the Prime Arks were at this time last year, but we can blame the voles and drought for that. From what I've read, Chester will get quite large once established - good thing it is thornless!
Chester produces a main crop in the spring on floricanes (last year's canes). This is one of the most cold tolerant varieties and should get through our normal winters with floricanes intact. though none of our winters have been "normal" lately
I got lucky and one of the Chester bushes formed a small clump of berries. The fruit is lower and hidden from the birds so it has ripened on the bush. The flavor is really good, but I imagine the tender berries might not ship as well. My berries usually just go hand to mouth. Next year's crop will be a much better example of Chester's fruit.
Later this fall, after the fruit is all eaten, I'll prune the bushes and increase the vole protection for the winter.