I grew a "tree" out of a lemon seed. As I'm not living in a climate for lemon trees I'm trying to make an indoor bonsai out of it. I'm not sure if it is good bonsai material. Will it build enough bark? Can I get the leaves small enough for a bonsai? Any experiences?
I did this for a few years with a seedling. The trunk will change from green to gray bark when it gets about the diameter of a small straw. The leaves will reduce in size but not in a proportion that is suitable for a small bonsai of less than a foot tall. I found pictures where it seemed to be more suitable for a large bonsai of two to three feet tall. At that size the thorns and leaves are more in proportion to the trunk.
Soil composition is essential for success as this question about lemon trees shows. For a bonsai I favour a watering wick so the plant has ready access to water but is never soggy. One or two days of inattention when it's hot and years of work can be compromised.