There’s an art to the proper pruning of palms

How do you know if you’ve properly pruned your palms?

There are some telltale signs.

A properly pruned, and healthy palm, should have a round canopy and green leaves from the top of the canopy down to the crown.

Unfortunately, too often palms are pruned too much — making them unattractive, unhealthy and weaker than a properly pruned palm.

Palms are not supposed to look like a flat rake or feather-duster.

The concept that “hurricane pruning” strengthens palms against strong winds and improves the tree’s health is contrary to research observations.

Palms with a more natural canopy are able to withstand higher winds and have less chance of becoming a structural hazard in a storm when compared to those that have been “hurricane” cut.

Pruning can damage the sensitive growing points, or heart, at the top of the plant, nestled at the base of the leaves.

With repeated over-pruning, palms can develop a tapered appearance just below the leaves, at the heart of the palm, which can become a weak point especially in high winds.

These plants have evolved in locations with a great potential for high wind storm events, so they are built for these conditions.

Palms rely on their leaves for nutrition, so removal of leaves/fronds drains the plant of vital nutrients. Research shows that nutrient-deficient plants have smaller leaves, reduced ability to make food and reduced canopy size. With repeated removal of green leaves, the palms may have smaller and weaker trunk diameters. These factors can lead to weakened and unhealthy plants.

Removal of nutrient deficient (not dead) leaves will eventually starve the plant of nutrients leading to the slow death of the palm.

So, which palms need to be pruned?

Tropical palms with crownshafts, or areas of the plant with bright green, tightly clasped leaf bases just above the trunk, do not need pruning. Many of the tropical palms will self-shed when leaves are dead, so very little pruning is required to maintain these palms. On these palms, old, dead leaves will simply fall off by themselves through a natural process.

However, these plants may sometimes exhibit nutrient deficiencies in older leaves toward the bottom of the plant.

A leaf that’s deficient in potassium will begin to brown very quickly and can hang on for months. Older leaves show this deficiency first, since their nutrients are being used as they are being sacrificed by the plant to nourish the younger leaves. A deficient leaf doesn’t mean it’s a dead leaf, just one that needs nutrients.

If the leaf stays in its normal position and doesn’t droop or fall down against the trunk, it’s still alive, but this is a sign that the plant needs to be properly fertilized.

Those leaves that drop and hang against the side of the trunk, out of a normal upright position, are dead and can be pulled or pruned away.

Queen palms, various date palms, etc., which do not have crownshafts, frequently will have dead leaves that droop and hang on for months unless they are pruned away.

When pruning, be sure that pruning equipment is properly sanitized between use on different palm plants, as several fatal diseases can be spread from plant to plant by the equipment. A 5-minute soak in a disinfecting solution will help reduce the chance of spreading diseases.

Those palms with skirts made of dead leaves, such as Mexican fan palms, will eventually shed old leaves, but they can become hiding places for undesirable wildlife, such as rodents and snakes, so removal of skirts of dead leaves can sometimes be necessary.

So what, if anything, should be pruned from palms?

Flowers and completely dead leaves can be removed with no problems, but discolored or browning lower leaves should be left alone. They indicate that the plant needs to be properly fertilized.

If you find broken or kinked petioles (the long shafts leading from the leaf to the trunk), it’s acceptable to remove that leaf, especially if you fear it might fall and do damage.

The fruit of some palms can leave a mess at the base of the plant and cause unwanted sprouting. Removal of clusters of fruit is fine.

Some research even suggests that removal of flower and fruit stalks increases leaf production. Just keep in mind that any pruning should be done with sanitized equipment.

When should palms be pruned, if pruning is necessary?

There’s no specific time of the year when it’s better or worse to prune palms.

Only prune completely dead leaves when they appear, and certainly before a storm.

Pruning palms only when necessary will keep them healthier and you happier.

For information on how to properly fertilize palms and sanitize pruning equipment, call your local UF/IFAS Extension Office.

Dr. Whitney C. Elmore is the UF/IFAS Pasco County Extension Director and an Urban Horticulture Agent III.

Published March 29, 2017