Last winter I bought a “thornless youngberry”. It seems that it is reverting back to being thorny, is this normal or have I been taken advantage of?
It started that the backs of the leaves furthest from the roots started to get hairs where the prickles would normally be. These were thin and soft. Then as the cane got longer the hairs started to get more course and curved. As the cane grew even longer it has started to get these hairs too. Eventually some of these furthest up the cane started to turn into thorns.
I know that there are several forms of thornlessness in brambles. There is true genetic thornless, which this clearly isn’t. Then there is periclinal chimera thornless, which is thornless only in the epidermal layer of cells. They are known for sending up thorny canes if the root is damaged. This doesn’t really seem to fit either as the lower leaves and lower parts of the cane are still completely thornless. The cane and the leaves lower down still have absolutely no prickles or hairs whatsoever.
@Richard mentioned in another post that thornlessness can be induced with hormones. I have never heard of that before. Do you think that this is possibly what has happened here?
Do you think that new canes produced in spring will likely be thornless or has my new plant reverted to being thorny?
Also, out of curiosity, what hormones are used and how do they do it? I would love to learn more about this.