No, it will not bother them. The spines are very sensitive to touch/contact and will fold out of the way of pretty much anything, so it won't 'poke' the cuke or anything. I have 3 or 4 cukes and never had my pincushion bother any of them. The tentacles that they walk with, I think are pretty useful sensory organs as well so they know whether they are touching important/living things ( I think they truly like to decorate themselves with nice things). I had two meet up one night and it was a crazy thing to watch all the tentacle communication going on.