Palm Trees:

a Popular Custom Residential Accessory

By Gregory V. Harris, regional editor

Palm trees come in many varieties and sizes, and they are a popular item on many custom residential landscapes, but homeowners need to be aware of the best trees for their site, and how to maintain these trees.

Factors such as size of the mature tree; temperature where the tree will be located; available sunlight; and water source all need to be taken into consideration before purchasing palms.

Nick Popovich, lead designer and operations manager at Palm Trees of South Carolina, said growth palm tree industry has been rapid, primarily because property owners want something unique for their landscapes.

“The biggest challenge is tempering people’s enthusiasm and pointing them to more hardy species like Canary Island date palms that can handle nine of 10 winters here,” Popovich said of his customers in the Carolinas.

An enthusiastic yet uninformed customer visiting a nursery may select a juvenile species of palm, thinking its diminutive size ideal. At maturity, however, the palm could grow to 50-60 feet, probably too large for most properties. Oversized trees can of course interfere with overhead lines and underground conduits, and possibly threaten buildings if the tree was planted too close to the structure.

“Homeowners should consider the aesthetics of how palms will improve the architecture,” Popovich said.

In the Carolinas, popular palm tree species include the Canary Island date palm (Phoenix canariensis) and the sabal palmetto, the state tree of South Carolina. Colder climates can sustain palm tree species such as the needle palm (rhapidophyllum hystrix). According to Gary Gragg, owner of Golden Gate Palms and Exotics, the needle palm can handle temperatures of -10 degrees.

“These types of palms have insulated trunks, which makes them hardy to the colder weather,” he explained. “There are many species of hardy palms, but overall, as temperatures rise, the palm tree species count rises.”

Gragg’s home turf is the San Francisco Bay area, and in this part of the country, the most popular palm tree is the queen palm (Arecastrum romanzoffianum).

“This is just a great tree, and in Northern California, it is very prevalent,” he said.

Gragg describes the queen palm as a pinnate beauty with plumose, gracefully arching, and having spineless fronds of dark green color. The trunk is 12 to 24-inches thick and ringed. This tree has ivory with orange colored flowers, and sweetly edible fruit that is made into jelly in its indigenous region of South America. This palm tree is a fast grower, two to three feet per year, and reaches 50-60 feet.

“There were just a few of these trees in the bay area 15 years ago or so, but once stores like Home Depot began selling them, they became very popular,” he said.

Gragg said palm trees are a great addition to the landscape because of their root structure.

“Most trees have roots that can go from being hair roots to becoming three feet thick, which can lead to foundation and sidewalk damage, depending on which way they grow,” he said. “Palm roots are at their maximum thickness right away, and they sponge next to materials, rather than displace them.”

Gragg observed that with residential hardscapes getting larger and gardens smaller, palm trees are replacing larger species of trees as features of the landscape.

The queen palm has no thorns, but that’s not indicative of all palm trees. Some species, such as the Canary Island date palm, have sharp thorns, nature’s design to keep animals away from palm base. The thorns release an irritant that makes the wound aches for several days. Despite the dangerous thorns, Gragg said the Canary Island date palm is a must have for custom residential landscapes.

“This is the most beautiful, awesome tree around, and we recommend the homeowners looking to build a palm tree garden include two or three of these trees,” he suggested.

Though the queen palm and Canary Island date palm can grow 60 to 80 feet respectively, other popular species of palm trees mature to a somewhat smaller size.

“The pygmy palm is a great little palm that grows to about 10-12 feet,?EUR??,,????'?? Gragg specified. “The Mediterranean fan palm is also a good smaller palm.”

Gragg said a typical palm garden in Northern California may contain two or three Canary Island palms, several queen palms, pygmy palms and the Mediterranean fan palms. To add color contrast, Gragg recommends the installation of a blue palm like the blue hesper palm (Brahea armata), and a green palm such as the Guadalupe fan palm (Brahea edulis).

“Palm gardens can be mundane if only one species of palm is used,” he offered. “Ideally, you want to use between three and eight different species for a good-looking garden. More than that, and the garden may look chaotic.”

Like other plants and trees, palms are susceptible to bug infestations and diseases. Common problems for palms include diseases such as bud rot and ganoderma rot, and insects including the giant palm borer, palm budworm, and the royal palm bug.

Gragg offers the following tips to ensure the health of palm trees and viability of the palm garden:

Planting

When planting a containerized palm, dig a hole as deep and slightly larger in width than the pot size being planted. Mix equal amounts of a high quality compost with the native soil for backfill. Several handfuls of slow release Palm Pro fertilizer can be mixed into this backfill to promote lush growth and dark green color. Palms that have been freshly cut from the field (bareroot) need to be treated differently. Since these palms have fresh cut roots, they need to be completely encased by four to six inches of salt free sand to prevent the roots from rotting. The sand and the hole must be free draining. Built up water in the planting hole can become foul and cause rotting of the rootzone, and if left unchecked, eventually death of the plant. The root zones of these field dug or “bareroot” palms must remain constantly moist, but not saturated to promote future root and top growth.

Watering

Although drought tolerant when established, palms love water. Most palms derive from moist environments, such as rainforests, along streams, rivers, or near subterranean water sources such as an underground stream. And therefore, to look their best, keep palms constantly moist- before, during, and after planting. Deep watering is suggested, by pulsing spray heads at set intervals to allow seepage to the bottom most roots or running a slow application rate drip system to achieve the same effect. Sago palms (and most cycads for that matter prefer to go dry between waterings, since a constantly damp situation can cause rot.

Fertilization

Palms appreciate moderate to heavy amounts of fertilization to keep their best color and to promote rapid growth. Spring, summer and fall are the growing seasons for most palms in the San Francisco Bay area, and this is when fertilizer will be most useful to the palm. Slow release fertilizers are best.

Amounts to apply would be a cup full every three to four months for a 15 gallon plant, two cups for 24-inch box, three cups for 36-inch box, and four cups for large 48-inch boxed or field grown palms. Also a quick acting foliar feed can be applied in the early spring to jump start the palms after the cool winter hiatus.

Trimming Techniques/Options

For the most part, palms should be trimmed at least yearly if not more often (resorts trim monthly to keep a perfect look to the trees). Most palms look best if trimmed to the horizontal point, or 90 degree point. Palms should never be trimmed back past the 45 degree point. Always trim the palms back to the point of termination on the trunk below the last spines (if any).

Clustering palms, such as Phoenix reclinata or Chaemerops humilis, can be trimmed to a solitary structure, cutting off all the suckers at the base, or, more artistically, a clumping structure whereby one selects the best five or seven trunks, while cutting off all the remaining suckers.

When it comes to installing and trimming palms, Gragg noted that it’s best left to professionals. Popovich added that when trying to determine the health of a palm, the particular species of tree must be taken into account.

“Different palms react differently in areas of discoloration in foliage, fungal attacks, or even seeing particular insects,” Popovich said. “Each instance is different, but from proper amendments, proper fertilization and lucking out with beneficial weather, some palms will take hold-or wake up from suspended animation and take hold.”