we had a magnolia soulangia in our garden in UK. although it was a mature tree about 15 feet high it didn't fruit until we had been there several years. Since it started fruiting it has done so every year to a greater or lessr degree. The fruits are very strange, first you get a lumpy green pod which turns red then it splits open and bright red fruits shaped like smarties hang down on white threads about 1-2cm. long.The flesh around the seed is oily and birds love them. I think that it is now producing fruit because it is mature.