How to grow Washingtonia
The California palm or American palm (Washingtonia H. Wendl., 1879) is an arboreal species of the Arecaceae family. The name Washingtonia was chosen in honor of George Washington and is native to California and Arizona, where it reaches 30 m in height.
In this sheet we will see how to cultivate Washingtonia following the main agronomic tricks.
The Californian palm is a plant suitable for different climates, especially in temperate zones and is a plant, from an aesthetic point of view, ideal for parks and large gardens with exotic characteristics.
Washingtonia is an evergreen plant that has a slender trunk in the adult specimens, shorter and irregular in the younger ones. At the apex of the stem are fan-shaped leaves with pointed lobes, very similar to the leaves of the Chinese palm.
There are several varieties of this palm: we recall the Washingtonia Filifera, with greenish-grey fan leaves with pointed lobes that produce clusters of very small cream-colored flowers in summer and black berries in winter; The Washingtonia Robusta is also quite widespread, which is very similar to the previous one, but with palmate leaves with less filamentous tips.
Washingtonia is a palm that can be propagated by seed. Propagation should be done in a sheltered seedbed with soft, moist soil. The grown plants will then be transplanted into the ground in the spring.
For the choice of the most suitable soil, we must look for rich, dry and drained soils with sand and pumice stone. However, it grows well in sandstone, loose soils and does not tolerate wet soils.
For the exposure, also considering its origins, it is advisable to choose a bright environment with direct sun, but areas with a few hours of shade during the day are also appreciated.
However, Washingtonia is a plant that adapts to the most diverse climates, it tolerates hot ones well but adapts to living in colder climates where it can withstand even the most intense frosts.
The only precaution is not to plant it in areas subject to frost and strong winds, as the plant would be affected at the vegetative level. For this reason, in colder areas, it should be placed in areas more sheltered from cold winds.
Watering is necessary only for plants that are a few years old, after which the adult plants are satisfied with rainwater; it is however advisable to water them in the driest periods. Obviously, in winter, watering is superfluous and could be harmful for the onset of rot.
For fertilization it is advisable to provide abundant organic fertilizer, such as mature manure, during the sowing phase. The fertilizer should be mixed 50% with the soil removed from the hole. Subsequently it is possible to intervene every year, in the late winter period, always adding organic substance and mixing it with the first layers of soil. Never use nitric nitrogen.
Washingtonia, like other palms, should not be pruned; It is enough to have the cunning of periodically removing the dry and diseased leaves, also for a question of an aesthetic nature.
Among the diseases and pests, California palms also suffer from the attack of the red needle. This parasite is very dangerous and can cause the plant to die even in a year. Due to the characteristics of this insect, in order to determine its presence, it is mandatory to notify the competent phytopathological offices for the area.
