Palm Tree Care Page 2
To remove spines when the palm is still small and it is near walkways or driveways. Some palms like the Canary Island date palm (Phoenix canariensis),have sharp spines that can be dangerous if people come in contact with them.
- Some clumping palms may need to be thinned out or new growth pruned off if the palms get too big for the space in which they are growing.
- To remove fruit clusters, especially in public landscapes where falling fruit and flower debris can be messy and/or hazardous. Some palms generate copious amounts of seedlings near the parent. When mature, fruits may provide food for pests such as rodents and birds. The formation of fruit and seed takes strength away from the palm.
Rules for pruning:
- If the frond is yellow, brown or broken, prune it off. If green fronds must be removed, prune off as few as possible. Under no circumstances should palms be severely pruned. Severe pruning is characterized by the removal of fronds between the ten-o-clock and two-o-clock positions on the palm canopy. Never take off more green fronds than can be produced in a single year.
- Remove loose petioles or boots by hand. If they don’t pull off, leave them on.
- Climbing spikes damage the trunks of palms and may spread diseases from tree to tree when not sterilized.
- Always use clean pruning equipment, including saws and pruning sheers. Chain saws are difficult to clean and sterilize, and should not be used to prune fronds from palms. Pruning saws must be immersed in a 50/50 solution of bleach and water for five minutes.
- Cleaning equipment in this manner will help prevent the spread of diseases such as fusarium in date palms.
- There is never any good reason to top a palm. Most palms are single-trunked, having only one growing point. Once that growing point or bud is damaged or killed, so is the entire palm. Research has shown that buds of Washingtonia and Phoenix palms are 18 to 24 inches down from the emergent point (or very top of the trunk). Some people mistakenly think that topping will shorten a palm that has grown too tall or that it will make the palm branch like a regular tree. Both cases are false.
- A trunk can be removed from clumping palms such as the Mediterranean palms (Chamaerops humilis), and the rest of the palm will live -- although they may become susceptible to ganoderma.
- When tall palms need pruning, uses ladders or aerial lifts, and non-invasive climbing gear.
Reasons to minimize pruning:
- Removing most of its fronds yearly or more frequently weakens a palm and slows its growth. Mature fronds provide food for developing fronds, flowers, fruit, roots and storage reserves in the trunk.
- When green fronds are removed, the nutrients they would have produced are lost to the rest of the palm. Some nutrients move from older leaves to newer leaves as they die. With potassium and, to lesser extent, other nutrients deficiencies, removal of older green or chlorotic leaves exacerbates the deficiency. Nutrient deficiencies also cause narrowing of the trunk and decline in the size of the fronds. The palm must now obtain its potassium from younger leaves in the canopy. These previously green and healthy leaves will then become chlorotic and unsightly.
- Palms must store sufficient reserves of starch in their trunks to restore fronds in the event that a palm experiences some type of stress such as fire, frost or defoliation by storms or humans.
- Palms must have as many green fronds as possible to produce a continuous supply of food. Research has shown the need for a 2:1 ratio between juvenile and mature fronds in some palms.
- Fronds may take three to five years to mature. A large crown of leaves on a mature date palm with more than 125 fronds may have taken 15 years to develop from the most juvenile frond to the most mature frond. This includes primordial leaves in the bud that have not yet emerged.
- Never prune for cosmetic purposes. Some people will prune Canary Island date palms to look like giant pineapples, or will skin fan palms to look like more tropical palms. Desert palms are not tropical, and it is best to accept that and not try to change them into something they are not.