Text by Richard van-C. Adkins, Forestry Supervisor, Parks andRecreation Department; Design by Erika Finbraaten, HistoricPreservation Planner, Historic Preservation Office

1/09 500

PALM MAINTENANCEIN HISTORICDISTRICTS

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Historic

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to be patient and wait for the flowering cycle tobe complete. Otherwise, if pruned too early,additional flower stalks may develop and will hangfrom the palm head the remainder of the year.

As a general rule, planto begin pruning datepalms in late May andfan palms in mid-June. Cut fronds closeto the petiole base ofthe frond (the petiolebase is where thepalm frond attachesto the trunk of the

palm) without damaging the live trunk tissue.

The use of climbingspikes should beminimized. Eventhough most streetlandscaped palms canbe pruned safely froman aerial lift, somepalms still need to beclimbed. Palms donot compartmentalizeand seal wounds like trees. Injuries to palmtrunks are permanent. Retaining the petiolebases or peel on palm trunks helps protect palmsfrom spike injury.

There are numerous certified landscape and treecontractors that can provide palm pruningservices. Information regarding the hiring of localarborists and additional resources concerning thecare of palms and trees can be found at thefollowing Web sites:

www.treesaregood.org isa-arbor.comaztrees.org treelink.comphoenix.gov/FORESTRY

For additional information, contact the HistoricPreservation Office at 602-261-8699 or Parks andRecreation Department at 602-262-6501.

For more information or a copy of this publication in analternate format, contact Mary Reyna at 602-261-8699/voiceor 602-534-5500/city TTY relay.

Palms have been a part of the Phoenix arealandscape since the early 1900s. The palm’sstately appearance has come to be associated notonly with the pioneering history of the area, but acomforting desert oasis feel in the Valley of theSun. Palms have been planted throughoutneighborhoods and business districts by residentsand developers, often defining the landscapepalette of the surrounding community. In thecity’s historic districts, they are a characterdefining feature.

There are four main species of palms found in thestreet landscapes of Phoenix:

• Two species of fan palms: - the California fan palm

(Washingtonia filifera), and- the Mexican fan palm

(Washingtonia robusta)

• Two species of date palms: - the date palm (Phoenix

dactylifera), and- the Canary Island date palm

(Phoenix canariensis).

Although people often refer to palms as “trees,”they technically are not true trees. Palms areconsidered arborescent monocots, or “tree-likegrasses.” Palms differ structurally from trees inthe development and organization of growth cells.

While palms located in theirnatural habitat do not needpruning, palms in an urbanenvironment do require annualmaintenance to remove deadfronds and fruit stalks that canbecome unsightly andpotentially hazardous.

Correct pruning is a keycomponent to maintaining palmhealth. Many people

indiscriminately cut palms to remove nearly all ofthe fronds. This tendency to over-prune palms isnot a recommended practice and can harm thepalm’s health over time.

Live, green fronds manufacture food for the palmand should be left as long as possible. Palms donot store energy as efficiently as trees and severepruning can deplete energy resources and stresspalm health, causing a gradual decrease in trunkdiameter and strength.

The following are nationally acceptedarboricultural maintenance standards for pruningpalms:

Palm fronds should not bepruned higher than frondsoriginating at a 45-degree anglefrom horizontal. This methodretains adequate live, greenfronds to produce food for thepalm while removing brown,dead fronds and fruit stalks.Date palms often are pruned tofronds originating at a 60-degree angle from horizontal toprovide a fuller, more tropicallook.

Removing flower stalks prior to the developmentand set of the palm fruit can save pruning timeand money as well as the energy resources of thepalm used in forming the fruit. Date palms inPhoenix flower each year in April and May, whilefan palms flower in May and June. When planningannual pruning maintenance activities, it is best

Severely over-pruned date palm

Severely over-pruned fan palm

Properly pruned fan palm

Properly pruned date palm