Palms are iconic symbols of tropical and Mediterranean environments. In general, they are a low-maintenance plant, which adds to their popularity as a choice for outdoor landscapes and for indoor growing in containers. The rate of growth is variable. A palm that grows fast in Australia may grow more slowly in Miami. One that grows fast in Miami may grow slowly in California. Species, location and climate are the most important factors in determining the growth rate of a palm.
California fan palm
California palms (Washingtonia filifera) have a moderate to rapid growth rate. They will reach a height of 30 m (100 ft) at maturity in warm climates. They are hardy throughout the UK, except in the north of England and Scotland. The leaves are fan-shaped (hence the name) and can grow up to seven feet long. Because the California Fan Palm grows quickly, landscapers should consider its growth habit when choosing a planting site, as the tree will dominate the landscape.
Mexican palm (Washingtonia robusta) is a fast grower native to Baja California and Mexico. In addition to California, the Mexican fan palm is commonly planted as a landscape palm in the warmer states of the United States and will thrive in Ireland and the Gulf Stream-affected west coast of Great Britain. It is sometimes confused with the California Fan Palm, but you can tell a Mexican Fan Palm by the size of its trunk. The California can have a trunk as wide as 60 cm (2 feet), while the Mexican trunk is thinner, measuring only about 30 cm (1 foot) wide. The leaves reach a length of about 1.5 m (5 feet). The tree produces white flowers in spring. Once the flowers fade, the tree produces edible berries.
Mediterranean fan palm
The advantage of the Mediterranean palm (Chamaerops humilis) is that it is one of the most cold-hardy palms. It can withstand the cold winters of the coldest parts of Britain, and can certainly withstand the heat in higher areas. The Mediterranean palm, however, is a slow-growing plant. This might only be a concern if you’re planting it as a landscape specimen for a home where you don’t intend to live long. Mediterranean will have a somewhat short stature, reaching a mature height of 4.5 to 6 m (15 to 20 feet). The leaves are blue-green or gray-green in color, and the tree typically bars several trunks. Its small size and wide spread – which can extend from 1.5 to 6 m (5 to 20 feet) – make the Mediterranean fan palm an excellent choice for home landscaping.
The windmill palm (Trachycarpus fortunei) is another slow grower, but a good choice for a home landscape. Unlike the Mediterranean, the windmill has a single, slender trunk. The growth characteristic of the trunk is interesting in that it grows inversely – narrow at the base and wider as it grows upward. The leaves grow in a fan-like pattern resembling a windmill (hence the name). Due to the compact nature of the windmill, it can be grown indoors as a container plant and is cold hardy throughout the UK. The Windmill Palm should be planted in a location where it has some shade and protection from the hot afternoon sun.