ARIZONA LANDSCAPE PALMS

1 ARIZONALANDSCAPEPALMSELIZABETH DAVISOND epartment of Plant SciencesJOHN BEGEMANPima County Cooperative ExtensionAZ1021 12/2000 Issued in furtherance of Cooperative Extension work acts of May 8 and June 30, 1914, in cooperation with the Department of Agriculture, JamesA. Christenson, Director, Cooperative Extension, College of Agriculture and Life Sciences, The University of University of ARIZONA College of Agriculture and Life Sciences is an equal opportunity employer authorized to provide research, educational informationand other services to individuals and institutions that function without regard to sex, race, religion, color, national origin, age, Vietnam Era Veteran's status,or ExtensionPContentsLandscape Use .. 3 Adaptation .. 3 Planting PALMS .. 3 Care of Established PALMS .. 5 Diseases and Insect Pests .. 6 PALMS for ARIZONA .. 6 Feather PALMS .. 8 Fan PALMS .. 12 Palm-like Plants .. 16 This information has been reviewed by university luxuriant tropical appearance and statelysilhouette of PALMS add much to the ARIZONA other plants are as striking in low and mid elevationgardens.

2 Although winter frosts and low humidity limitthe choices somewhat, a good number of PALMS areavailable, ranging from the dwarf Mediterranean Fanpalm to the massive Canary Island Date palm. Several ofthe PALMS described in this publication are unavailable ornearly so in ARIZONA . They have been included becausethey have the potential to broaden the landscapeversatility of this important plant group. In time they maybecome more available as a result of consumer demand orthe risky and expensive process of introduction by thenursery UsePalms are planted in groves, clumps or as singlespecimens for accent or background planting. They areused around public buildings, in parks, along avenues,near swimming pools and patios and in the gardenwherever a bold effect or suggestion of the tropics isdesired. The large-growing PALMS provide a dramaticfeeling of space. In an architectural sense, they serve todefine large spaces and to create strong vertical accentsand skyline silhouettes.

3 These qualities have a unifyingeffect in massive building complexes and large-scaleplantings. The smaller growing palm species are equallyvaluable in the home LANDSCAPE , providing shade, shelterand tropical often are planted in straight, formal rows alongroads and drives. Another interesting effect can beachieved by making a group or clump planting of severalpalms of the same species in varying heights andspacings. Such natural groupings make striking featuresfor entrances, pool plantings and gardens in general. Theslow growing and dwarf species can be planted underother trees and in tubs or planters where they remaineffective for to choose? One of the important considerationsin selecting a palm is to choose an adapted species thatwill mature to a reasonable size for the , the pretty little palm brought from the nurseryin a 5-gallon container may grow one day into a monsterthat overpowers house and garden.

4 Analyze the plantingsite for vertical space, avoiding roof overhangs. It is aserious mistake to plant tall-growing PALMS under powerlines. In addition, all PALMS need a certain amount of careand grooming. Some fast-growing species require moreattention than others. Your choice should reflect howmuch time, effort, and expense you are willing to devote generally can be grown below the 4000 ft levelin ARIZONA . However, microclimate may make thedifference between success and failure in a given pockets, where nighttime cold air tends to collect,should be avoided, especially for the tender species. Palmsare most sensitive to cold as small plants. As a treeapproaches maturity, it withstands low temperatures withless injury. However, few of the tropical and subtropicalpalms grown in southern Florida and southern Californiacan tolerate the winter freezes that occur even in themildest sections of ARIZONA . On the other hand, thedesert s high summer temperatures and low humidityeliminate other palm species, notably those from humidcoastal climates.

5 Shelter from strong winds can sometimesbe provided by hills, buildings, or groups of other palm species, California Fan Palm (Washingtoniafilifera) is native to the oases and canyons of ARIZONA andCalifornia. Other PALMS may be grown in the greatestvariety in the landscapes of Yuma, Phoenix andneighboring areas. As the elevation increases, the numberof adapted species generally tend to decrease. The hardiesttypes such as California Fan, Mediterranean Fan,Windmill Fan, Canary Island Date, and Mexican Blue canbe grown in such communities as Kingman, Globe,Nogales and Douglas. During severe winters even thesehardy species, especially young plants, may freeze PalmsSmall Containerized PALMS :The best time for planting PALMS is during warm weatherwhen root growth is most active. Soil temperatures above65 F aid root establishment. This generally includes theperiod from April through September. The preferred time islate spring to early fertile, well-drained soil will promote luxuriantgrowth.

6 One of the most important requirements is that theplanting site be well-drained. Caliche, hardpan, com-pacted soil layers, or abrupt changes in soil texture preventgood soil drainage and aeration. The result is constantlywet, saturated soil in the planting pit and almost certaindeath of transplanted test for drainage , fill the hole with water. Allow todrain, and fill a second time. If the second filling does notdrain out within 24 hours, alternate provisions must bemade for drainage . If necessary, dig a chimney down to aporous strata to permit excess irrigation water to drainfrom the not amend the backfill with manure or organicmaterial. This will eventually result in the palm sinkinginto the hole. Sand at more than 1/3 total volume isacceptable, if the soil is extremely the planting hole as deep as the root ball and 2 feetwider on each side. Set the crown of the containerizedpalm at the original soil level so that soil temperatures,water and aeration are conducive to root expansion.

7 Donot cover the crown or young trunk with soil. New rootswill emerge both above and below the rootball. Settle thebackfill soil with a water from a thoroughly at planting time. Make a berm abovegrade (about 2 feet out from the trunk) so that slow soakfrom hose or bubbler can gradually fill it and saturate theroot zone. PALMS that are set out in warm weather willprobably need to be watered every day for the first 2 weeksafter planting. Check the soil moisture content in the rootball to determine this, since the container soil will often dryout faster than the surrounding backfill soil. The goal atthis stage is to keep the root ball moist but not constantlysoggy roots begin to grow out and draw moisture from agreater volume of soil, irrigations can be spaced furtherapart. Bubbler Irrigating: every day for the first 2 weeksgradually increasing the interval to every 7 days forthe remainder of the first growing season, dependingon soil type (see below). Drip Irrigating: with 4 emitters spaced 2 feet fromthe trunk, and 8 emitters spaced 4 feet from the to start, then gradually increase the timebetween irrigations according to the soil both cases, the timing and frequency of irrigations willdepend on how well the soil holds water.

8 Sandy soils willdrain quickly and need more frequent applications thanclay soils. Always water to a depth of 2 ft. Check with aprobe, long screwdriver or piece of rebar to see if the soil issoft to that depth. A layer of mulch spread 2 4" over theirrigated zone will help to reduce soil temperatures andconserve water so that less frequent applications Pre-dug PALMS :Large LANDSCAPE PALMS are usually dug from establishedgroves or LANDSCAPE plantings. They must be handledgently and with care in all phases of the transplantingoperation. Rough handling or bumping can damage theterminal bud and kill the tree. Once dug from the originallocation, PALMS should not be left lying out in the hot sunfor long periods of time either at the digging site or at theplanting site. The root ball should be kept moist, and thetrunk securely braced in transit. One way to accomplishthis is to cover the root ball with damp burlap. Do not useplastic for this purpose, since it will trap PALMS regenerate some roots from the cut ends,but other new roots develop from the root crown.

9 In somespecies, increased root regeneration has been measuredwith longer cut stubs in larger root balls. Root regenerationdepends on adequate water and oxygen. At times the rootball may be deeper than it is wide. In general, larger rootballs make for better establishment in less than of dug PALMS is stored in the trunk and lostthrough the leaves. For this reason, up to half of olderliving fronds may be removed for transport. The remainingfronds are tied together over the tender bud with abiodegradable twine to protect it from drying and sunscald. (On some species the bud may be actually splintedto protect it from breaking.) Depending on the time of yearthe palm is planted, the fronds should be left tied aroundthe bud for 2 to 3 months. In arid climates, the chance of thetwine actually rotting is slim. When new growth begins tobulge out below the point at which the fronds are tied, therope may be cut to gradually release the foliage.

10 Leave theold fronds in place for a month more to protect the bud andnew planting hole for large pre-dug PALMS should beonly as deep as the root ball and should drain in 24 hoursas discussed above. Backfill need not be amended. Loosenthe soil 3 feet beyond each side of the root ball to encouragelateral root pre-dug PALMS should be planted at theiroriginal planting depth. Planting too deeply may causeroot suffocation due to restricted oxygen, nutritionaldeficiencies, root rot disease and frequently loss of t plant the crowns deep simply to ensure that thetrees don t fall PALMS may be braced when installed with atleast three 2x4 lumber braces (at 45 from the ground)against 1 ft lengths of 2x4 that are vertically strapped orbanded around the the trunk with nylon, burlap, or other suitablematerial where the one foot lengths of 2x4 are secured. Donot nail these vertical pieces into the trunk. Supports canbe removed when fronds are large PALMS immediately as discussed irrigations to a depth of 2 ft may gradually bereduced to once a week during the first warm for differences in soil texture: clay soils will needwatering less often than sandy soils.