Royal palm trees belong to the genus Arecaceae, which has 3,000 species of shrubs, vines and trees. They are distinguished from other palm trees by their 10-foot-long fronds and smooth gray trunks.
Royal palms grow about 1 foot a year and reach heights of 50 to 100 feet. They produce yellow flowers and purple or black inedible fruits. The leaf blades are between 18 and 36 inches long.
Royal palms are hardy in Zones 10 and 11. Zone 10 is the hottest in the continental United States and Zone 11 comprises Hawaii.
Royal palms are usually grown from seed but can be purchased as established plants. Royal palms like a lot of water but can survive a short drought period.
Royal palms are used by municipalities like Miami to line boulevards. They have a tolerance for salt and can be planted near the ocean. Royal palms can be used as a specimen plant by itself or planted in groves.
The royal palm bug eats the young leaves. The palm leaf skeletonizer eats the leaf tissue between the veins. Giant palm weevils and scales are other insects that can damage the tree. Ganoderma butt rot is a fatal fungal disease.