how many types of palm trees are there and are the palm tree ever green  

There are thousands of species of Palm Trees. They are considered to be tropical in nature, but most people are not aware that cold hardy palms may be planted outside without any visible damage from temperatures as cold as -20°F. You can see this as far north as Canada and Switzerland. Palm trees, like banana trees, give your home and garden that tropical look, usually found around pools and family recreational areas. Once established, Palm Trees are relatively maintenance free and are not significantly bothered by insects and disease. There are two basic types of Palm trees and we will tell you about the Northern and Southern Palms. Afghanistan palm - Pakistan Palm and Mazari Palm - This palm may be the coldest hardy in the world, according to authoritative doctors on the subject of Palms. Their fruit is also edible and very popular to eat in that impoverished nation. The tree grows very slowly and thrives in desert conditions. Dwarf Palmetto or Sabal minor - Blue Palmetto is widely distributed throughout the Southeastern United States and grows about 6ft. tall in shaded locations. This Palm is very difficult to transplant from the wild.
Needle Palm - Rhapidophyllum hystrix is a needle palm, which are the most frost hardy palms on earth surviving -20°F weather with little damage. Saw Palmetto or Serenoa Repens - Sassafras Palm has been found growing wild as far north as Virginia, Washington D.C., and New Jersey, and is cold hardy to -10° F. Windmill Palm or Trachycarpus fortunel has been known to be cold hardy for many years and have been growing in Switzerland for 100 years along Lake Lucerne.