Carolyne, if you had not posted this question I would never heard of a kotota berry or have known that they were introduced in the US in 1984 as a unique blackberry cultivar. As such, I'm very surprised you have had no success rooting them from cuttings, because blackberries will often root where they touch the soil. Probably the best way is to root the suckers you are bound to have. As an alternative, try putting your cuttings in moist perlite, dipping them in rooting hormone before you do so.
@Douglas Hunt will @Carolyne Livingston have more success if she puts it in the earth and covers with a glass jar?? My great grandmother seemed to be able to root any rose this way. I'd be interested in more insight into this. Thanks
I've never heard of that method, Gail. It would certainly be worth an experiment.
Please see this site for detailed info on propagating blackberries :) http://www.gardeningknowhow.com/edible/fruits/blackberries/propagating-blackberries-cuttings.htm