Available in 3 gallon, 7 gallon, 15 gallon and 25 gallon sizes. Sold in 3G, 7G, 15G and 25G sizes. Scientific Name of Roystonea regia (roy-STON-ee-a REE-jee-a). Widely distributed along the Gulf Coast shores of Mexcio and along parts of the Caribbean coast, these palms grow naturally along rivers, swamps and at the edge of rain forests. Also known as Cuban Royal Palm and Florida Royal Palm trees. They require adequate moisture and near tropical climates. These trees often survive freezes, and it has been recorded that they can recover from temperatures in the mid-20s Fahrenheit. Royal Palm Trees should be planted in full sun with adequate irrigation. they can grow up to 100 feet high with a diameter of ~2 feet.