Six on Saturday: Talk To The Palm


That is how horticulturists say, “Talk to the hand.” During the past three and a half decades that I have been working with landscape designer, Brent Green, I have deduced that there is not a specimen of Washingtonia filifera in the Santa Clara Valley, or anywhere else for that mater, who is any more interested by what I have to say than he is. Nonetheless, I appreciate palms.

1. Rats! I thought that was who chewed on a petiole of my favorite young windmill palm from Western San Jose. However, this picture shows several small slices made with a straight blade!P00222-1

2. Pleats of an aging fronds of the same windmill palm demonstrate that surfaces exposed to the south deteriorate before those exposed to the north. The frond was tilted up for this picture.P00222-2

3. Windmill palm seedling is one of a few that I pulled from a landscape nearby, but could not bear to discard without at least trying to find a home for them; as if we need another palm here.P00222-3

4. Hesper palm is more interesting. I brought two here while they were nearly dead. The other did not survive. This one tried to recover, died back again, and is now trying to recover again.P00222-4

5. McCurtain scrub palm seed that I was so pleased to procure earlier is what is obscured just below the surface in this flat. I am concerned that the compost might not have been ready.P00222-5

6. Seed of other odd species of palm were found in a package that had been in storage for a few years. As if we need another palm here, all will get sown. Sadly, few are likely to still be viable.P00222-6

This is the link for Six on Saturday, for anyone else who would like to participate:

Scrub Palm

104 seeds for the price of 10!

Of all the strange seed I brought back from Oklahoma, none were from the scrub palm, Sabal minor, that is endemic to McCurtain County in the very southeaster corner of Oklahoma. I did not get to that region.

Sabal minor is nothing special to those who are acquainted with it. However, a variety that was selected from those in McCurtain County, which is known simply as Sabal minor ‘McCurtain’, is becoming increasingly popular in climates where winter weather is too cold for other palms. It is sufficiently resilient to frost to survive in New England and Canada.

I just wanted it because it is from Oklahoma.

Since I did not collect any wild seed, I had considered purchasing a seedling of the ‘McCurtain’ variety online. It would have been rather expensive for a single seedling. I was pleased to find seed of the same variety that were significantly less expensive for several seed. I know they grow slowly, but I am in no hurry. I gain bragging rights as soon as the seed germinate.

Unexpectedly, I was even more pleased to find seed on eBay that were collected from trees that were collected from the wild in McCurtain County, but were not of the ‘McCurtain’ variety! I know that seems trivial, and maybe even less desirable to those who want a garden variety, but for me, such seed are more closely related to those I would have collected if I had been there.

For $6.00, I expected delivery of a packet of ten seed of Sabal minor from McCurtain County. I could not pass on a deal like that. Instead, I got the 104 seed in the picture above! That is ten times what I was expecting. They will grow into more scrub palms than my garden can accommodate. RAD!

Herbaceous Trees

P91005KPalms are like ‘Red Delicious’ apples. It seems that most people dislike them; but they also seem to be very popular. Seriously, if only a few people like ‘Red Delicious’ apples, why are they so common in supermarkets? If most of us dislike palms, why are they so common in the San Jose Skyline?

I suspect that palms really are as unpopular as they seem to be, but that they are also very conspicuous within their situations. Not only are they focal points of the landscapes in which they live, but most types eventually stand as tall as the tallest trees in the neighborhood, and some get significantly taller. They are innately the most prominent trees within their neighborhoods.

Palm are not like other trees though. Arborists may classify them as ‘herbaceous trees’. They are foliar plants while young, producing increasingly large leaves from terrestrial rosettes. They only ‘launch’ and start to develop their trunks after the formerly terrestrial rosettes have grown wide enough to do so.

Not only are their trunks no wider than their associated foliar rosettes, but they get no wider as they grow taller. The base of a trunk of a palm is as wide when the tree is only a few feet tall as it will be when the tree grows to forty feet tall. Mexican fan palms are only wider at their bases because they start out like that.

Palms with slender trunks can launch much sooner than those with wider trunks. It does not take long for their rosettes to get as wide as their trunks. Canary Island date palms have rather plump trunks, so may need to mature for many years before they launch.

Yuccas and dracaenas are not really palms. Their trunks expand and develop branches as they grow and mature.

Trees Need Clearance From Utilities

30320thumbPalm trunks grow in only one direction; upward, toward sunlight and away from gravity. Each trunk is equipped with only a single terminal bud. If that bud encounters an obstacle, it can not be pruned around it. Palm trunks that get get too close to high voltage cables, or that might sway too close with a breeze, must therefore be removed to maintain minimal clearance from the cables.

Queen palms are notorious for getting planted under high voltage cables because they are so often impulse purchases that get planted without much planning. They are popularly planted along rear fences, exactly where high voltage cables are often located. Mexican fan palms often grow along rear fences as well because that is where birds and rodents are likely to drop the seeds.

Trees with single central leaders, like redwoods, spruces and certain pines, will be disfigured if their main trunks need to be topped for clearance from cables. Removal of such trees is often more practical than this sort of disfigurement. More extensively branched trees like sycamores, ashes, oaks and elms, are more adaptable to clearance pruning if it is not too severely disfiguring.

It is much simpler to not plant trees that get too large under high voltage cables. Elsewhere in the garden, where there is enough lateral (side) clearance, vertical clearance is not such a problem for larger trees. Small trees like redbud, purple leaf plum, photinia and various pittosporums, either do not get tall enough to reach upper cables, or will require only minimal pruning for clearance.

Below high voltage cables, the lower cables are for lower voltage, telephone and television. ‘House-drops’ are the cables that extend from utility poles to houses and other buildings. Although clearance is not so important for these lower risk cables, limbs that lean on them and blow around in wind can be abrasive. Sagging limbs can cause utility cables to sag more than they should.

Unfortunately, those who prune trees for utility clearance are efficient, but rarely arboriculturally correct.

Palm Treevia


This is a quick trivia question.

Which of these three states has the most native genera of palm?

1. California

2. Hawaii

3. Oklahoma

4. None of the above


This is not a trick question. Notice that it asks about genera rather than species.

1. California is home to many exotic specie and genera of palm; but only ONE is native. The California fan palm, Washingtonia filifera, which is also known as the desert fan palm, lives in isolated groves out in the Mojave Desert. Because it prefers hot and arid desert climates, and does not like to be watered too generously through summer, it is now a very unpopular palm for landscapes.

2. Hawaii, is populated by many more exotic species and genera of palm than California is, but only species of the ONE genera of Pritchardia are native. Many of the exotic genera were imported by ancient Polynesians to produce food. Others were imported later for landscaping.

3. Oklahoma is the sort of place where only a few of the toughest of exotic palms can survive outside. Yet, McCurtain County, in the very southeastern corner of Oklahoma, is home to ONE very rare but nonetheless native variety of dwarf palmetto, Sabal minor.

4. ‘None of the above’ is the correct answer to the question because none of the other choices above have any more native genera than any of the others.

So, although Hawaii really does have more native species of palm, it has no more native genera than California or even Oklahoma. Each of these three states has exactly ONE native genus of palm.

I am sorry that I have no good pictures of any of these palms. All three of these pictures were obtained online. I have experience with neither the dwarf palmetto of Oklahoma, nor any of the species of Pritchardia of Hawaii. However, the California fan palm happens to be my all time favorite palm, even though it is not very happy here. It is such a stately palm, and those grown from the same seed batches are uniform enough for formal plantings. They are the palms that flank the famous Palm Driveway of the Winchester House in San Jose, as they were popular for flanking driveways and roadways in California and Arizona during the Victorian period. I did happen to see California fan palm in the wild outside of Palm Springs while in school in the late 1980s and can tell you that they are spectacular in their native habitat.


Note: The elderly and deteriorating California fan palms that flanked the Palm Drive of the Winchester House have been replaced with palms that are hybrids of California fan palm, Washingtonia filifera, and Mexican fan palm, Washingtonia robusta. They are more tolerant to the irrigation of the landscape around them.


P80630KWhat are they doing out there, in those two pots in the island of such a vast parking lot? It is hard to say from this distance. They are so isolated. They might be happy and healthy summer blooming annuals. They might just be weeds. They could be plotting World domination. Plants can do some weird things in isolation.

Mexican fan palm is the most familiar palm in Los Angeles. Some know them as skydusters because they are so tall and lanky, and do not seem to have anything better to do than lazily brush against the undersides of clouds as they float by. In Los Angeles, there are not many clouds to keep them busy, and there is not even much smog anymore. Mexican fan palms certainly do not make much shade, and because they are so tall, their little shadows land in neighbors’ yards. They are so tall that you might be able to see them from wherever you are merely by looking towards Los Angeles. Instead of getting Frisbees and kites stuck in their canopies, they collect satellites. When they drop one of their big leaves, it burns up in the atmosphere.

In their natural environment, Mexican fan palm lives in a large and mostly contiguous native range (areas) in which individual colonies are not isolated for too long. Pollen gets shared rather thoroughly. Trees are consequently very similar throughout the range. Slight genetic variation is only perceptible in regions such as Los Angeles, where various groups of trees are grown from seed collected from various regions of the native range.P80630K+

Sometime in the ancient history of the specie, a few individuals decided to leave the rest of the herd and go live in isolation out in the adjacent deserts. They could only survive where there was a bit of water, so they inhabited any oasis they could find. This might have happened as some trees migrated up canyons that had perennial creeks flowing through them only to have the lower portion of the canyon go dry as outflow from above decreased. Seismic activity within the region has a way of altering the outflow of springs. Anyway, these more reclusive palms eventually became a separate species, or subspecies, or variety, depending on the botanist providing the information. This separate species (or subspecies or variety) is now known as the California fan palm, or the desert fan palm. It thrives on the hot and arid desert air, but is not very happy in milder and more humid coastal climates. (I am sorry that I do not have a good picture at the moment.)

Unlike Mexican fan palm that lives in a big contiguous range, California fan palms lives in small isolated colonies where they can not share their pollen freely with other colonies. Over thousands of years, each colony adapts to its specific environmental conditions. Genetic variation within colonies is not perceptible, but is quite obvious in landscape situations where trees grown from seed from different colonies can be compared.

California fan palm is much shorter and stouter than Mexican fan palm. It does not need to compete with too many other specie out in the desert. The trunks are straighter, and the canopies are fluffier. Unlike the very informal and relaxed Mexican fan palm, it is an excellent palm for formal landscapes. It is the specie that flanks the famous Palm Driveway at the Winchester House in San Jose. The only stipulation for these formal installations is that all the palms must be grown from the same batch of seeds procured from the same colony.

Location – Location -Location!

P80422Speaking of which, this is not the right location!

This unhappy Mexican fan palm may have grown here from seed, as they often do. They are notorious for growing under utility cables because that is where birds drop so many of their seed. Perhaps the seed for this one was dropped by a bird perched on the sign many years ago.

Ironic, isn’t it. Birds tend to perch on utility cables and signs and in trees and everywhere that palms should not be planted. How often do they drop seeds out in the open, where whey will not encroach into something as they grow up? Why can’t they drop palm seeds in places where palm trees would actually be an asset? It happens sometimes, but not as often as palms appear where they are not wanted.

The picture below shows three larger Mexican fan palms that were intentionally planted in the original landscape, with a smaller palm between two of the larger palms. The palm in the first picture is barely visible in front of the sign in the background, and is about the same size as the smaller tree that is more visible between the taller trees.

It is possible and perhaps likely that the two smaller palms were not planted intentionally. It is also possible that someone actually planted them.

It does not matter now. The palm in front of the sign needs to be removed. The removal of all the foliage will not kill it. It will generate new foliage that will again obscure the sign if the tree is not eliminated soon. There is no way to prune the palm to divert growth around the sign. It has only one terminal bud, and is unable to generate another if topped. Palms under utility cables have the same problem. Once they get too close to the cables, they must be removed.

Getting back to the first picture. The shock and awe of the defoliation of the subject Mexican fan palm was likely sufficient distraction to prevent anyone from noticing the queen palm foliage peeking around the right side of the sign. Unlike Mexican fan palms, queen palms rarely grow from seed here, especially in a spot where there are no other queen palms nearby. Yes, someone planted ‘another’ palm in the same spot!P80422+

Two Heads Are Better Than One

P80221Three or four might be better than two. Perhaps that is what this queen palm was thinking when it decided to get extras.

This is not a good picture, and the tree is a bit too shaggy with old foliage to see what is going on inside clearly. To the left, a secondary limb is curving downward and away from the main trunk, before curving back upward as a secondary canopy. Another limb is developing immediately above this secondary canopy, and another is visible to the right of the main trunk. It is hard to say how many individual canopies are within the collective canopy of this single specimen.

What is weird about this development is that the popularly available palms do not form branches. Think of it. When was the last time you saw a palm tree with a limb or branches? Before you answer that, yuccas (such as Joshua trees) and dracaenas are not palms. Also, clumping palms like Mediterranean fan palm do not form limbs from their main trunks. They merely develop multiple trunks from basal pups.

The very few specie of palm that develop branches regularly are very rare and live very far away. Date palms, either grown for dates or recycled into landscapes from displaced date orchards, have the potential to develop pups higher on their trunks, but rarely do so.

Palms are only trees because they have trunks. Otherwise, they are merely really big perennials, with single terminal buds from which all their foliage, flowers and fruit develop. If deprived of the terminal bud, a palm can not generate a new one, which is why a palm will die if topped.

So why does this queen palm have more than one terminal bud? It is impossible to say.



Remember the Beverly Hillbillies? That was a really lame sitcom; but it was somehow very popular at the time.

Each episode began with the stupid jingle that explains how and why the formerly impoverished but suddenly wealthy Clampetts left their home in Bugtussle and moved to Beverly . . . Hills that is.

As they drive their decrepit Oldsmobile down Bedford Drive just west of downtown, the palms flanking the roadway are prominently visible to the left and right. This strictly regimented collection of Canary Island date palms alternating with Mexican palms was not very big back then, in the early 1960s. By the 1980s, they were strikingly grand. Sadly, they are now deteriorating from old age. Many of the broad Canary Island date palms have succumbed to pink rot, so are now absent. Some of the Mexican fan palms are also lacking. It is saddening to see them now knowing how grand they were not too long ago. Although they are being replaced, they will never be as formal and uniform as they were as a monoculture (or biculture) that was planted all at the same time back in the late Victorian period. Even if it were possible to remove all of the trees and plant new ones at the same time, such conformity went out of style decades ago.

Arborists see these historic trees differently. They know that just one Canary Island date palm is likely infested with rats. Such a grand collection must be infested with a disturbingly large population of rats. Within a canopy of a Canary Island date palm rats, are safe from most predators, and get quite a bit to eat from the fruit produced by the female trees. (Most Canary Island date palms are female, with only a few taller and less billowy male trees for pollination.)

When a Canary Island date palm gets cut down from the base, it falls with a big SPLAT on the ground, followed by a blast of wind containing every Frisbee, baseball, tennis ball, kite and whatever got stuck in the tree over the previous few years. After a brief pause, but before the the baseballs stop rolling in the gutters, a herd of all surviving rats flees the scene. Most hide in the closest shrubbery they find. Some scurry up other nearby palms. It can really blow your image of the Canary Island date palm.

Green Roof

P71125Is this a bad idea for a green roof?

Is it a houseplant that got too big?

Is it a wheelchair accessible tree-house?

None of the above. It is just weird architecture, designed to preserve a rare Chilean wine palm. The tree was probably planted in the front garden of a Victorian home that was on this site before the site was redeveloped. Chilean wine palms were more popular back then; and this one seems to be about that age. Although it seems to be healthy now, the constriction in the trunk indicates that it had been stressed by the redevelopment, which undoubtedly covered much of the established root system. The time it took for the length of trunk above the constriction to grow coincides with the estimated age of the building below. The tree very likely had better access to rainwater before.

Because it is a palm, the trunk will not get any wider than it is. Because the trunk is so stout, it probably does not move much in the wind. However, the blue tarp around the trunk indicates that there is a problem with the roof leaking around the trunk. It is obviously difficult to get a good seal.

It is impossible to determine from this picture if the building is built on a slab or a simple foundation. A foundation would be a bit healthier for the tree. Perhaps it is more accurate to say that a foundation is less detrimental to the tree than a slab would be. It probably would be better for the building too, since a slab could have been displaced by new roots emerging from the base of the trunk.

Perhaps all this discussion is pointless. This weird but creative idea works. Although distressed and very likely embarrassed, the tree was preserved, and shades the building below.