English ivy (hedera helix) can make great bonsai, IF you can find an older trunk. This species grows wild here in Va. and I've seen a number of arm thick or thicker trunks growing up oaks at old plantation sites. Variegated cultivars generally make poor bonsai, as their leaves tend to make the plant look "sickly."
ANY species that makes a woody trunk and has reliable backbudding can be made into bonsai. Nick Lenz made a great bonsai out of a poison ivy vine he collected. It was a pretty nice little bonsai. I think he said someone stole it...Guess you'd have to wear gloves to prune it. There are pretty awesome old poison ivy vines here too. Some in protected national sites around No. Va. are well over 300 years old and can be as big around as a man...
Careful...do not tempt faith. I learned it is the opposite and instead of developing resistance to it, you actually get desensitized and reaction gets worse overtime. I spoke with several tree trimmers, woodworkers, and arborists who shared same experience.the poison ivy thing sounds kinda cool, I actually am not very allergic to poison ivy on most of my skin my face and stomach are the exception, I walk around the woods barefoot all summer here, must have built some resistance to the toxin over time.
Careful...do not tempt faith. I learned it is the opposite and instead of developing resistance to it, you actually get desensitized and reaction gets worse overtime. I spoke with several tree trimmers, woodworkers, and arborists who shared same experience.
but people with childhood allergies often outgrow them
I know this but let me assure you...no one I know ever went from sensitive to immune with poison ivy. We have a saying ...there are only 2 types of people...those who are sensitive to poison ivy and those who will be.
It is like playing a computer game...you have several tries. Keep using them and you are dead.