Has anyone ever heard of making a bonsai out of mesquite or jujube trees? Thank you.
Yes. I have seen Jujube in a book or Bonsai magazine but not Mesquite. However almost everything has been tried by someone as Bonsai. Even huge trees like Redwood and fast growing like Weeping Willow(I once tried a Cottonwood). There are some EXCELLENT Ponderosa Pine Bonsai(long needles)and a beautiful Daimyo Oak which normally has very big leaves. You can see this one on the internet. The most critical item is to neither drown nor starve the roots for water. Proper potting medium is very important for good drainage while also retaing moisture. Personally I have 2 Ponderosa Pines and just got a little Daimyo Oak(Quercus dentata)and also have 3 different Cycads among other more normal trees. I hope this will help you and good luck.