Magnolias are one of a kind and are very slow growers. Magnolia trees come in different varieties. One of the more popular choices is the Little Gem. This Dwarf Magnolia only reaches 20 to 25 ft. tall, and up to 10 to 15 ft. wide if let go, but can be trimmed like a christmas tree its whole life. The Southern Magnolia (Grandiflora) is a Pinellas County tree permitting option when needing to have a tree replaced. There is also the Bracken Brown Beauty which are a larger variety. These trees can get 50ft tall over 15-20 years. 30Gallon will be required for code.
Magnolias are hardy in USDA Zones 7-9; however, there are some cultivars that survive winters far North in zone 7. The magnolia will tolerate wet, soggy soil and best done in moist, rich, slightly acidic soil that is amended with compost or potting soil will get the tree off to a good start.