Rfonte,
I have never grown them from seed, but I did hear on this Forum that they grow very slowly til they are about 3 feet tall, give or take, and they they grow a little faster.
They are so reasonably priced at any nursery or big box store, most people buy them at a decent size and grow them from there.
If you do find seed, give it a try, and please report back
as to how the seedlings did.
They aren't fast growing shrubs/trees so you must have patience.