Pruning away dead fronds will keep the tree tidy and clean. It is also recommended to periodically spray the tree down to remove dust and insects. This palm is rarely bothered by disease or pests but spider mites, scale insects, diamond scale, or giant palm borer beetles can occasionally become a problem.
Light
The ideal location for a California fan palm is a spot with full sun; at least 6 to 8 hours each day is preferred. They can tolerate partial shade but do best with lots of sunlight.
Soil
This hardy tree can be grown in a wide range of soil conditions and is tolerant of salt, making it a great choice for coastal areas. However, it prefers rich, well-draining soils. Neutral to acidic soil pH levels are ideal, but the California fan palm can also tolerate alkaline soil.
Water
Like most desert plants, the California fan palm is drought tolerant once established. Be sure to water a newly planted tree regularly until it regularly produces new growth. Providing about one inch of water per week will help keep the young tree healthy. Once established, this tree does not need regular watering. Give it an occasional, deep watering to ensure its continued health.
Temperature and Humidity
The California fan palm thrives in dry to semi-dry climates. Though these plants are not often thought of as northern plants, the California palm can withstand frost and light snow. It can survive temperatures as low as 15 degrees Fahrenheit and can be grown in USDA hardiness zones 8-11.
Fertilizer
Provide these trees with a fertilizer specifically designed for palms. Feed them throughout the growing season to encourage healthy growth, following the feeding instructions on your specific fertilizer.
Pruning
Each year, old palm fronds will turn brown and wilt, creating a shaggy ring around the trunk of the tree. This skirted affect, caused by leaving the dead fronds on the tree can, add interest. If this is your preference, it’s a good idea to plant your tree away from walkways and commonly used areas as falling leaves can be a hazard. To keep the trunk open and clean, pruning must be done yearly to remove the brown fronds.
How to Grow California Fan Palm From Seed
The California fan palm does not produce suckers like other varieties of palm trees. Therefore, growing this palm tree from seed is the best option. Fortunately, seeds sprout easily, making this a great option for propagation. Alternatively, these seeds can be planted directly in the garden in areas with consistently warm temperatures.
Potting and Repotting California Fan Palm
Young trees can be initially kept in containers. They prefer loose roots, so choose a large pot to accommodate growth. Eventually, though, they will become stunted in a container. When this happens, they will need to be planted in the ground to allow for further growth.
Overwintering
Because these hardy palms can withstand temperatures down to 15 degrees Fahrenheit, the California fan palm does not require any additional care to survive the winter when grown within its appropriate zones. For trees on the northern edge of their growing zones, it is best to give them protection from the weather by bringing potted trees indoors or covering the base of planted trees in a thick layer of mulch.
How to Get California Fan Palm to Bloom
Although it is known best for its regal appearance and fan-shaped fronds, the California fan palm does produce flowers in the summer. These flowers are small, creamy white, and are supported on eight to ten foot long stalks. These little flowers later produce small, black fruits. The fruits are edible but sparse. Cutting the flower stalks is not necessary, but can be done to prevent the production of seeds and subsequent seedlings. To encourage flowering, be sure to provide these palms with fertilizer, plenty of sunlight, and adequate water.
Common Problems With California Fan Palm
The California fan palm is a hardy, disease-and pest-resistant tree that can handle a range of soil conditions and hot, dry weather. They do not often present a gardener with many challenges. However, even very hardy plants can encounter the occasional problem.
Yellowing or Browning Leaves
Yellowing or browning leaves can be a sign of disease. One cause is diamond scale. If, on close inspection, tiny black spots or diamond-shaped, shiny fungi are found on the leaves, diamond scale is to blame. To treat this, be sure you are providing all the water and nutrients needed to keep your palm healthy. Make sure the soil drains well. This will help ensure that the palm is healthy enough to fight the fungal infection. Pruning away old foliage can help keep the tree clean. For infected, living fronds, use an anti-fungal treatment to kill off the diamond scale.
Discolored, Wilting, and Falling Leaves
Pale, discolored, and soggy fronds that wilt or fall off the tree are a sign of overwatering. If this occurs, hold back water for a bit. Use a soil amendment, such as sand, to help increase the drainage.