There is no such thing as a bonsai tree. There isn’t
It is not a genetic strain of plant life, you cannot buy seeds of bonsai trees, add water and compost, and then sit back and watch a seedling emerge, and shape itself into a mirror image of a tree, such as seen in the film ‘Karate Kid’. Think of it more as a technique whereby the grower, over a period of time, trains the seedling through pruning and wiring, into the desired shape.
Growing from seed gives you more control over the end result, but has inherent in it all the problems associated with raising anything else from seed, such as damping off, drying out, heavy footed pets and fluctuating conditions. However, it can, and is done, and not only can it give a great deal of personal satisfaction, but it is cheap!! Sycamore, chestnut, oak, pomegranate, lemon, orange, etc can all be collected by strolling through the local park or supermarket.
Growing bonsai is cruel.
You stunt their growth…don’t allow the roots to grow, bind their branches with wire, like the feet of Japanese ladies. OK, cruel? Well, it may appear so at times. However, trees/shrubs that are bonsai’d when looked after correctly, will extend their lifespan by, on average, 25%.