We gave a talk today about palms — with botanical facts, ideas for using them in the landscape, and information on growing them successfully. We handed out notes to the people who attended, presented below:

Palms 101

Selecting palm species

• Screen by these criteria: aesthetic appeal, design function, frost-tolerance, heat requirements, wind tolerance, sun tolerance, and water needs. Most soils can be amended.

Exceptional choices for the cool-summer Bay Area:

Rhopalostylis spp. (nikau & Norfolk palms)

Parajubaea spp. (Andean “coquito” palms)

Trachycarpus spp. (windmill palms)

Brahea edulis (Guadalupe palm)

Chamaedorea spp. (bamboo palms)

Livistona spp. (Australian & Chinese fan palms)

Jubaea chilensis (Chilean wine palm)

Howea forsteriana (kentia or paradise palm)

Hedyscepe canterburyana (umbrella palm)

Ceroxylon spp. (wax palms)

Arenga micrantha (Tibetan sugar palm)

Excellent choices for inland extremes:

Butia odorata (pindo palm)

Brahea spp. (Mexican blue palm and many others)

Jubaea chilensis (Chilean wine palm)

Chamaerops humilis (Mediterranean fan palm)

C. humilis var. argentea AKA “cerifera” (blue Atlas fan palm)

Dypsis decipiens (Manambe palm)

Livistona decora (ribbon palm)

L. nitida (shiny Australian fan palm)

L. australis (Australian fan palm)

Trithrinax spp. (Argentine fan palm)

Sabal spp. (palmettos)

Trachycarpus spp. (windmill palms)

Phoenix dactylifera (true date palms)

Washingtonia filifera (California fan palm)

Rhapidophyllum hystrix (needle palm)

Nannorhops ritchiana (Mazari palm)

For ocean-side or windy bayside locations:

Butia

Chamaerops

Brahea edulis

Phoenix canariensis

Jubaea

Trachycarpus wagnerianus

*Worth a try: Parajubaea, Howea, Livistona nitida, L. australis, Rhopalostylis, Phoenix reclinata, P. sylvestris, P. dactylifera ‘Zahidi’ & ‘Medjool’, Sabal, Trithrinax

Banana-belt treats for the Mission, Telegraph Hill, Oakland, Tiburon, Los Altos Hills, Santa Cruz hills:

Pritchardia minor (Hawaiian fan palm)

Archontophoenix cunninghamiana (king palm)

Dypsis baronii (hardy areca palm)

Caryota maxima & C. obtusa/gigas (fishtail palms)

Ravenea glauca (mini-majesty palm)

Rhapis spp. (lady palms)

Livistona chinensis (Chinese fan palm)

Notes on common species:

o       Washingtonia: W. robusta, the Mexican fan palm and the “cockroach” of palms, will tolerate but not look good in the chilly fog belt, while it will thrive but get occasional winter foliar damage in the coldest inland climates. It’s also often the wrong selection because it gets too tall. The California fan palm, W. filifera suffers fatal fungal infections anywhere with significant summer marine influence (zones 15-17). In very wet-winter regions its crown suffers through winter & spring, but in inland extremes it thrives.

o       Phoenix canariensis: Because of the risk of fatal fusarium wilt on Canary Island date palms, it’s best to use Jubaea chilensis wherever possible instead; specimens of the latter are expensive and rare, however.

o       Phoenix dactylifera: Selections ‘Zahidi’ and ‘Medjool’ tolerate our cool, humid summers better than the cheaper and more common ‘Deglet Noor’. True date palms can also replace Canary Island date palms where specimens are needed.

o       Syagrus romanzoffiana: the queen palm is a good choice for a fast-growing, narrow, medium-size palm tree where summers are slightly warmer than the foggiest districts and moisture and fertilizer can be provided. In windy, chilly-summer neighborhoods west of Arguello or Masonic it looks terrible. Inland it will thrive and quickly reach maturity but can be killed by the rarest 30-to-50-year freezes. It’s at its best where winter temperatures stay above 25F and summer highs consistently surpass 70F.

o       Trachycarpus fortunei: The Chinese windmill palm can tolerate drought, wind, and some neglect, but at the expense of looking trashy and parched. The best-looking Chinese windmills get even moisture, some shade when young, and fertilizer that includes magnesium. They also benefit aesthetically from group planting and you can give them an updated look by pruning off the furry leafbases. Prettier cousins are T. wagnerianus, T.  martianus, and T. latisectus.

Growing Palms in the Bay Area

• Good drainage & consistent water: few palms tolerate drying out, and few tolerate cold, wet roots.
• Fertilizer: Apply NPK 3-1-3 + 1 magnesium in March, June & September.
• Plant small for best adaptation and speediest growth.
• Palms start growing slowly and accelerate.
• Good to plant slow-growing species large.
• Palms are slow to adapt to increased light levels.

Planting & Transplanting

• Spring-summer best season.
• Never manipulate rootballs.
• Tight fit with foundations & walls works fine.
• Keep original rootball moist and irrigate surrounding soil to encourage establishment.

Design

• Repetition & naturalism: in groves, at differing heights
• Not just trees: shrubs, screens, containers, understory foliage, and the role nothing else can match, palm.
• One palm does not equal one tree.

Portraits of Random Rare Palms for SF Bay Area:

Parajubaea torallyi var. torallyi

Pasopaya Palm

Coco

A fast-growing, very rare, majestic tree from high in the Bolivian Andes. Looks like a husky coconut palm. Give it full sun, good drainage, ample water, regular fertilizer, and stand back and watch it develop into a graceful and substantial palm with a hefty, fiber-clad trunk and finely divided pinnate leaves. Once established, it will tolerate drought. Can reach 20 feet tall in 15 years. Produces edible miniature coconuts. Enjoys the Bay Area’s cool and warm microclimates and will tolerate moderate frosts. Plant as young as possible and with no root disturbance. Minor seashore tolerance, but otherwise adaptable from the foggy Outer Sunset to Walnut Creek (Sunset zones 14-17).

• Feather palm; no crownshaft
• Max height: 80 feet in 100 years
• Max crown breadth: 20 feet
• Extremely rare
• Majestic
• Fast growth
• Hardy

Parajubaea cocoides

Coquito

California Coconut

This exquisite and rare coconut look-alike graces the colonial streets of Quito, Ecuador, and other Andean cities. No other palm looks more like a coconut overall. It produces a lush crown of shiny, dark-green leaves atop a rather slender trunk. Extinct in the wild, it’s one of the fastest growing palms for San Francisco and other bayside climates, requiring our cool summers to thrive. Tolerates light frosts. Plant as young as possible in its permanent, full-sun location – it will not tolerate root disturbance – provide ample water and fertilizer, and within 15 years it will be a 15-foot tree producing one-tenth-scale edible coconuts. Not likely to tolerate seashore conditions, but otherwise it is happy in the foggiest locales as well as in mild areas ringing the Bay (Sunset zones 16-17). Once established, it will survive occasional drought but prefers regular water.

• Feather palm; no crownshaft
• Max height: 50 feet in 75 years
• Max spread: 17 feet
• Edible seed
• Rare
• Uniquely adapted to SF Bay Area climate
• Fast growth

Hedyscepe canterburyana

Umbrella Palm

Big Mountain Palm

One of the most colorful, clean-looking and graceful palms we can grow in San Francisco, this native of Australia’s tiny Lord Howe Island in the South Pacific develops a powdery blue-green trunk and crownshaft, apple-green foliage, and lipstick-red fruits the size of robin’s eggs. It prefers a bright, semi-shaded position in well-drained soil, and regular water and fertilizer. Its slow growth and modest proportions make it perfect for small gardens, reaching 10 feet in 30 years, with a crown spanning five feet. It tolerates light frosts but should be planted only in San Francisco and the most protected climates of other bayside and coastal cities like Sausalito, Belvedere, Oakland and Berkeley (Sunset zone 17). Minimize root disturbance upon planting. Thrives in the foggiest neighborhoods, but not especially tolerant of direct coastal exposure.

• Feather palm; crowshaft
• Max height: 30 feet in 75 years
• Max spread: 3-5 feet
• Exceptionally beautiful
• Rare

Lepidorrhachis mooreana

Little Mountain Palm

The perfect fog-belt palm, this extraordinarily rare species grows in one half-square kilometer area atop a windy, mist-draped mountain on Australia’s tiny Lord Howe Island in the South Pacific. It’s a fast-growing, small tree that prefers “full fog” exposure west of Twin Peaks and Divisadero, and a bright but not roastingly sunny spot in banana belts of San Francisco and milder bayside and coastal climates (Sunset zone 17). In full shade it will grow happily but more slowly. Adapted to wind, but not direct coastal exposure. Its diminutive size (to six feet tall), clean, exotic appearance and adaptation to our unique climate make it an exceptional plant for San Francisco urban gardens, especially in those foggy zones.

• Feather palm; incomplete crownshaft; self-cleaning
• Max height: 6 feet
• Max spread: 3 feet
• Extremely rare
• Uniquely adapted to SF Bay Area climate

Ceroxylon alpinum

Coffee-Belt Andean Wax Palm

One of the endangered wax palms of the Andes, this tall Columbian cloud-forest tree will function as a luxuriant foliage element for decades before developing its slender trunk and becoming a spectacular skyline feature. Plant in bright shade or half-sun in rich, well-drained soil, water regularly, and it will steadily produce long, dark-green, glossy, silver-satin-backed leaves. Tolerant of light to moderate frosts, it is best in foggy coastal and humid bayside climates (Sunset zones 16-17 and mild, redwood-dominated parts of 15). Not tolerant of direct coastal exposure.

• Feather palm; loose crownshaft; self-cleaning
• Max height: 100 feet in 100 years
• Max spread: 15 feet
• Rare
• Exceptionally beautiful
• Uniquely adapted to SF Bay Area climate

Livistona nitida

Carnarvon Palm

A cold-hardy and beautiful rare fan palm from Queensland, Australia, this fast-growing species is adaptable to inland as well as bayside and even fogbound climates. The well-proportioned, elegant crown grows atop a tall, ramrod-straight, slender trunk. Plant in full or half sun in well-drained soil, water moderately, and fertilize regularly for speedy growth to 10 to 15 feet in 15 years. Probably at its best in warm-summer areas, it will also provide great satisfaction in foggy zones (Sunset zones 8-9, 14-17).

• Fan palm
• Max height: 100 feet in 100 years
• Max spread: 18 feet
• Rare
• Hardy

Chamaedorea plumosa

Plumosa Palm

Baby Queen Palm

The fastest-growing, most adaptable, and best-scaled palm for small gardens, this delightful native of Chiapas, Mexico, tolerates light to moderate frosts, deep shade or nearly full sun, and wind, among other bugaboos of San Francisco gardening. Its fluffy leaves quickly rise on a thin green stem to create a languorous, weeping crown in deep shade, or a crown resembling a small queen palm in full sun. It appreciates ample water and fertilizer, but, once established, it will tolerate dry periods. Shoehorn it into narrow light wells, or plant it out to give vertical definition in broad, exposed spaces. In the windiest and coldest districts, plant in a protected lee spot, but otherwise it’s adaptable to most urban and coastal Bay Area climates (Sunset zones 15-17).

• Feather palm; crownshaft
• Max height: 20 feet in 15 years
• Max spread: 3 feet
• Rare
• Small palm for small gardens
• Versatile
• Fast-growing

Transplanting palms is pretty darn easy, but if you follow the procedures that are best for planting woody trees and shrubs you can slow their establishment or even kill certain species.

The University of Florida IFAS Extension has published a useful series of articles on palm cultivation, including one on transplanting palms by Timothy K. Broschat. It’s full of interesting photographs and clear info.

Because palms continually produce new roots from the base of the trunk, there’s no need to cut or unravel the rootball of containerized palms when they go into the landscape. And because new roots only develop from the base of the trunk, planting palms with their roots exposed can thwart the development of new roots and thus the healthy growth of the plant.

We see lots of palms planted too high and languishing, and we’ve made the mistake of ripping apart a rootball and waiting years for healthy new growth to emerge from the crown of leaves.