September 11 Remembrance Garden, Winslow, Arizona

P71118The main complaint about this Remembrance Garden is that there is no garden. Two steel girders from the destroyed World Trade Center stand vertically on pedestals within a concrete slab shaped like the site of the World Trade Center. The pedestals are set within squares of stones that correspond to the outlines and locations of the of the World Trade Center Twin Towers #1 and #2 within the World Trade Center Site. The outlines and locations of the other buildings of the World Trade Center are designated by darker concrete within the slab. There is no real synthetic landscape. Only a few ash, cottonwoods, pines and junipers are scattered about.

This might be the most perfect landscape I have ever seen.

Please don’t get me wrong. I appreciate good landscapes that do what they were designed to do. Most of the prettiest are designed to make spaces more appealing. They make our homes more homey. They make our offices more comfortable. They shade streets and parks to make them cooler during warm weather. Whatever landscapes are designed to do, they should do it well. That is precisely what is demonstrated so perfectly by the landscape, or lack of synthetic landscape, at the September 11 Remembrance Garden of Winslow in Arizona.

This is not a comfortable space. It is not intended to be. A bit of shade might be nice during the hot summers in Winslow, but would detract from what this space is set aside for. The starkness and harshness are important here. There is nothing to distract, nothing to obscure, nothing to interfere with what the Remembrance Garden is designed for.

The Remembrance Garden is located outside of the eastern edge of town and on the western edge of the Painted Desert. It might have benefited from more of a synthetic landscape if it had been located in town. A few trees and evergreen shrubbery might have been useful to soften any urban surroundings. Actually, the girders were temporarily located in a lightly landscaped area when they first arrived in Winslow, and then moved to this site a bit later. Despite the complaints of a few insensitive tourists, it is hard to believe that this setting and landscape were not very thoughtfully planned out.

P71118+

Mother In Law Tongue

61116What an unflattering name for such striking tropical foliage! The pointed and strap-shaped evergreen leaves of mother-in-law’s tongue, Sansevieria trifasciata, stand vertically, about two or three feet tall. They are rather rigid, and seem to be plastic with a glossy finish. Almost all modern varieties are variegated with silvery gray, white, cream or yellow stripes or banding. Dwarf varieties stay shorter, with flared foliage.

Because it tolerates shade and neglect so well, mother-in-law’s tongue has always been a popular houseplant. It is sometimes grown in pots outside where it can be sheltered from frost or direct sunlight that might roast the foliage. Pups can be divided from overgrown old plants, but will develop shorter leaves until they recover from separation. Crowded plants might get green sports (unvariegated mutant shoots).

Even Houseplants Can Appreciate Rain

P71116Everyone is from somewhere. Not everyone is fortunate enough to be from California. Most of the various plants in our gardens, even if grown locally, are descendants of plants that were collected from all over the world. Most houseplants are from tropical regions. They perform well as houseplants primarily because they tolerate the sort of partial shade that they would get as understory plants in dense tropical forests.

Along with this advantage of tolerance to shade, tropical houseplants come with other disadvantages, such as an intolerance to frost. So, they are able to live inside the home, but are unable to live very long outside where winters are cool. Even areas of Southern California that do not get frosty can get cool enough to make many tropical houseplants uncomfortable. Consequently, they are confined to their homes.

That might seem to be acceptable to those who not think like plants do. Really, do houseplants even want to go outside? Maybe not. However, shelter from frost and cool weather also shelters them from other weather, such as wind and rain. Without wind and rain, any dust that collects on the foliage stays there. Mealybug and scale insects can proliferate and produce sticky honeydew, which also will not rinse away.

This is why some of us like to occasionally put our houseplants in a cool shower to rinse them off. It eliminates much of the dust, and clears out the stomata (respiratory pores). It does not kill mealybug or scale, but sets them back a bit, and rinses off the honeydew. Showering is also a good way to soak and rinse toxins from the soil. Only African violets, gloxinias and a few plants with fuzzy foliage should not be showered.

The only thing that works better than showering is rain. (Remember that wet stuff that starts to fall from the sky this time of year?) Rain is gentler, lasts longer than a shower, and is located outside where the mess of wet houseplants is not so bothersome. The only disadvantages of rain are that it can be cold, and is often accompanied by wind. A slight breeze would help agitate dirty foliage and dislodge dust, but strong gusts can knock houseplants over, and damage large leaves that are not adapted to any wind. Plants should be sheltered from both wind and direct sun exposure that might happen if the plants are not brought in before clouds clear after the rain.

Epiphyte

P71108A plant that clings to another plant for support without parasitizing it is an epiphyte. Some do it to get a bit more sunlight closer to the ceiling of a dense forest. Others do it to get up off of the forest floor to avoid competition with conventionally terrestrial plants. Maybe some just want to avoid grazing animals. It is often difficult to determine why plants do what they do.

Spider plants, ephiphyllums and many types of orchids, bromeliads and ferns are some of the more familiar epiphytes. Most do not actually cling to trees. They instead live in the crotches of limbs where debris from the foliar canopy above accumulates. Either way, they do not need much organic matter in which to disperse their roots, and some need none at all. Many collect what they need from the air and precipitation.

This is not about an epiphyte.

It is about a Mexican fan palm that thought it was epiphyte.

You might have though that the picture above depicts a common Mexican fan palm next to a surly London planetree. With closer inspection, you will notice that the palm lacks a trunk at ground level. The utility pole visible below the palm is not attached to it, and does not support it. Yet, the palm does not just hover there. It grew from a cavity in the London planetree.

Most of us know how many plants self sow in weird places. Sometimes they appear where they are welcome. Usually, they end up in pots with other plants, too close to pavement, or in rain gutters that have not been cleaned out enough. Of course, big trees commonly appear under utility cables. Once in a while something self sows in a decaying cavity of a tree.

Most of us have enough sense to remove self sown trees and plants that appears where they can not live for long without causing problems. Those of us who hire gardeners tend to trust and hope that the gardeners would exhibit the same sort of common sense. After all, that is part of what they are payed significant money for.

Unfortunately, Mexican fan palms are not epiphytic. They are just too heavy, even when young.

P71108+

Sweetgum

71122One of the big four for mild climates, sweetgum, Liquidambar styraciflua, develops an excellent display of mixed yellow, orange and red, regardless of how quietly autumn tries to sneak in. Of the other three, Chinese pistache is more orange with less yellow, flowering pear is more ruddy, and gingko is only bright yellow. They all get very flashy color, but sweetgum just might be the flashiest.

Some trees can favor one color or another. Distressed trees tend to be more pinkish red. Vigorous trees might have more yellow. Garden varieties were selected for reliable variability; although ‘burgundy’ has more dark red. Only trees that are too sheltered, too vigorous or pruned too aggressively will lack color. Urban trees can get fifty feet tall, but do not get very broad. Structural deficiency, aggressive roots and spiky seed capsules the size of ping pong balls can be problematic.

Autumn Color That Proves It

71122thumbThere may not be a good time to talk about it this year. The late warmth really put a damper on some of the autumn foliar color. Some trees are dropping their leaves as soon as they start to turn color, leaving only fading green leaves in their canopies. Only the most reliable trees for autumn color, sweetgum, Chinese pistache, flowering pear and gingko, are trying to make up for lost color.

Now, just because these four trees happen to color well and reliably in autumn does not necessarily mean that they are the right trees for every application. No tree is perfect. Gingko comes close in regard to adaptability to a broad range of applications, but provides only bright yellow autumn color. Flowering pear can be an excellent tree in most regards, but it very susceptible to fire blight.

The other two eventually get too big for some applications. Chinese pistache gets broad with low branches, and old trees (that predate the selection of the standardized male cultivar) can be messy with tiny but profuse fruits. Mature sweetgum trees are notoriously messy with obnoxiously spiked mace-like fruits, and can develop serious and potentially hazardous structural deficiency.

There are certainly more trees and plants that can provide foliar color in autumn. These just happen to be four of the most reliable, and most brilliantly colored. Chinese tallow turns dark burgundy and almost purplish, but colors best in response to a sharp and sudden chill. Red oak turns a monochromatic brown like that of a paper bag, but of course, the color does not appeal to everyone.

Years ago, it was advisable to select flowering crabapples and flowering cherries while blooming in spring because that was the most accurate representation of their floral color. (Photographs were not what pictures are nowadays.) This is still good advice. For autumn color, it is probably better to observe trees around the neighborhood, and then identify those that are most appealing.

Once a few are identified, it is easier to research them to learn about their distinct characteristics, and to determine if they are appropriate for particular applications or situations. Some might be too big. Some might be too messy. Some are not as colorful as others. Persimmon has the added bonus of fruit. Crape myrtle blooms nicely in summer. It is better to know before planting them.

GREEN

P71112

GREEN – Greening Residential Environments Empowering Neighborhoods – allocates resources, procured from both municipal funding and private donations, to the installation, maintenance and protection of trees in public spaces within the collective urban forest of Los Angeles, and to the enforcement of environmental justice.

How is that for a mission statement?

It is no coincidence that GREEN is also Brent’s last name. He is quite vain. Really though, it works.

Brent has been planting street trees since we were in school in the 1980s, and did his first big project of thirty trees in the median of San Vicente Boulevard on his thirtieth birthday in 1998. This January, twenty years later, he will be planting fifty more trees.

Here and there, I will be writing more articles about these projects. They are too involved to write just one article about. For now, I would like to mention the Facebook page for GREEN, at https://www.facebook.com/GREEN-1518459741733375/. I am sorry that I can not devote more attention to it. I really should be writing more articles about what GREEN does.

There is more to it than just planting. Trees also require staking. Street trees need pruning for clearance above the roadways that they shade. Some trees needed to be injected with systemic insecticide for homopteran insect infestation. When mature Canary Island date palms were being stolen from the embankment of the Santa Monica Freeway and sold into other neighborhoods, GREEN was there to stop it, and to get at least one of the trees returned (although the neighborhood is still waiting for other reparations). GREEN has organized neighborhood clean-ups and graffiti abatement.

GREEN is in Los Angeles, but could be duplicated in other municipalities that could use more trees, or that already have trees that need maintenance. So many trees in America have tree preservation ordinances, but some of the biggest cities need to enforce their ordinances more diligently.

If you continue to read my blog, you will be reading more about GREEN. Again, the Facebook page is at https://www.facebook.com/GREEN-1518459741733375/

Arachnophobia

70927lthumbsparePerhaps I should see this movie. I hear that it is pretty lame. I sort of wanted to see it because it was filmed in Cambria, about thirty miles to the northwest of where Brent and I were in our last year of studying horticulture at Cal Poly in San Luis Obispo at the time. Yet, I never select movies. I always leave that up to whomever I am seeing the particular movie with. None of my friends ever wanted to see Arachnophobia. The one friend who you would think would want to see it because of where and when it was filmed wanted nothing to do with it. You see, Brent, the famous horticulturist and landscape designer who works outside where spiders live, is afflicted with Arachnophobia.

About a year before the filming of Arachnophobia began, in early 1988, Brent lived in Sequoia Hall at Cal Poly to the north of San Luis Obispo, and I lived south of town, about twenty minutes away. Brent called me up early one morning as I was getting ready to leave for school to tell me about a spider in his dorm room. Perhaps “tell” is not the best word to describe his frantic panic. I mean, he was totally freaked out!

I told him to wake up Jerry, his roommate who usually slept in a bit later, and have him remove the spider. He got even more frantic and told me that Jerry was up in the room. Well, . . . if Jerry was up in the room, and Brent was not with Jerry, I just had to ask, “Where are you?!” “I’m calling from the payphone in the lobby!”, Brent explained frantically. (Telephones were hardwired in 1988.) Okay, so this complicated things a bit. He actually ran from the room and down from the third floor before stopping long enough to use a telephone? I told Brent that he should go back up to his room and have Jerry remove the spider. He really freaked out, and exclaimed, “Are you not listening?! THERE IS A SPIDER UP THERE!!”

Somehow, after explaining that Jerry did not answer the telephone when he had tried to call a few time before calling me, Brent convinced me to rush over and stop by before class to remove the spider for him. Brent was in his pajamas without slippers when I met him in the lobby and proceeded up to his room, where Jerry had just woken up to find Brent gone and the door wide open. We both went to the lower left sill of the window where Brent had seen the terrifying spider, and found it, dead. Yes. . . dead. I rushed over there, parked in a red zone, rushed upstairs, all to kill . . . a dead spider.

Well, it was not exactly a dead spider. It was the molted exoskeleton of a spider. In retrospect, I should have told Brent either that it was a dead spider, or that we had found and killed it. You see, Brent and I studied entomology together, so we knew how this molting process worked for certain insects. Arachnids like mites and spiders use a similar technique. As they grow too large for their external skeletal structure, they shed it, and then hide out somewhere while their new exterior hardens into a new exoskeleton. So when I told Brent that we found the molted exoskeleton, he freaked out all over again knowing that the spider was still hiding in his room, and that it was BIGGER!

I do not remember how Jerry and I got Brent to go home the following evening. Perhaps his second best option was to come to my house, where spiders were quite common. We never actually saw the spider.

Spanish Bayonet

P71110From a simple picture, Spanish bayonet, Yucca aloifolia, is indistinguishable from the common giant yucca. The narrow leaves are about two feet long, and flare upward and outward from terminal buds. Plump conical trusses of waxy white flowers with purplish highlights stand vertically just above the foliage. The main difference is that the leaves are more rigid than they appear to be, with nastily sharp terminal spines.

The second most obvious difference becomes apparent as the trunks mature. These trunks get only about four inches wide, which is not quite stout enough to support their own weight. Some might get taller than ten feet, but eventually fall over. Terminal buds of fallen trunks curve upward, and try to grow vertically again. If not pruned away, old foliage browns and lays back against the trunks, like the beards of fan palms.

Trees Do Not Like Chimneys

P71027There are many reasons why fireplaces and their chimneys are not such a safety concern like they were decades ago. Only a few modern homes are even equipped with them. Installation of a new fireplace is outlawed in many municipalities, even if a fireplace gets damaged by an earthquake, and should be replaced. Urban sprawl has replaced almost all of the orchards and woods that once supplied affordable fuel.

Most of the few fireplaces and wood stoves that still get used are safer because their chimneys are outfitted with spark arrestors. Also, most combustible cedar roofs have been replaced by non-combustible roofing material. Nonetheless, chimneys can sometimes get overwhelmed by potentially combustible vegetation. Trees, large shrubbery and vines might need to be pruned for adequate clearance from the heat.

Vines like ivy, Boston ivy and creeping fig are sometimes allowed to climb chimneys because they do not damage bricks as easily as they damage painted surfaces. However, they can easily grow over the top of a chimney. Aggressive vines generate significant volumes of vegetation, and can accumulate even more from nearby trees. Because they are directly over chimney exhaust, they ignite as soon as a fir is lit below.

Trees that reach over chimneys take a bit more time to burn because heat dissipates somewhat in the space between the top of the chimney and the higher vegetation. Cypress, pine, eucalyptus, cedar and big junipers are very combustible. If they get close enough, ungroomed palms and yuccas can be even worse! Deciduous trees are mostly defoliated, and less combustible while it Is cool enough to use a fireplace.

Regardless, all chimneys need adequate clearance from vegetation. Trees and vines that were allowed to get too close while fireplaces were unused through summer will need to be pruned back before the first fire is lit to take the chill out of cooling autumn weather. Debris that collects behind (upslope from) chimneys should also be removed. It can be combustible while dry, and once dampened by rain, it can cause rot.

This is also a good time to start cleaning eaves-troughs (gutters) and downspouts. Yes, it may need to be done more than once if enough deciduous foliage continues to fall through autumn. Debris is easiest to clean out while dry (before it needs to be cleaned out), but unfortunately becomes messier with rain.