Simplify the following text for a Grade 4 native English-speaking person.
Original: Some species are popular as bonsai material because they have characteristics , such as small leaves or needles , that make them appropriate for the compact visual scope of bonsai .
Simplified: Good trees to make into bonsai have small leaves ( pine tree needles are leaves too ) . If the leaves are too big , the bonsai will not look like a small tree .