Those who crave fall color in mild climates should appreciate Chinese pistache, Pistacia chinensis. It is happy to provide fiery yellow, orange and red color in response to a slight chill. Actually, it retains its colorful foliage later into the season with mild chill than it does with frosty weather. Rain eventually dislodges all of its deciduous foliage through winter.
Because it is so resilient to harsh situations, Chinese pistache is popular as a street tree. Pruning is necessary to establish adequate clearance of broad limbs over roadways and sidewalks. Since roots can be shallow with regular watering, root barriers should protect nearby pavement. However, established trees do not need regular watering, if any at all.
Old Chinese pistache trees, as well as those that grow wild from seed, are either male or female. Female trees produce tiny but annoyingly abundant fruit. Modern cultivars are all male, and therefore fruitless. They may get more than forty feet tall, with broad canopies. The pinnately compound leaves are just about eight inches long.
Brent, my colleague down south, plants street trees. He has been doing so for decades. Some of the older trees are quite mature now. Brent telephones me to tell me whenever the first trees on opposite sides of a street meet in the middle. It is like a graduation for that particular colony of trees. The various species mature at different rates, so they ‘meet’ over their particular street on their own distinct schedule. Brent watches them all, and attends all of their ‘graduations’. Anyway, that is what the first picture reminded me of.
1. Redwoods meeting friends over a road is not uncommon here. For compact street trees that got planted at the same time on opposite sides of an urban street, it is an indication of maturity.
2. Shasta daisies are not exactly friends. They are just two of many separate flowers on the same mature plant. They are composite flowers, so each one contains many tiny but distinct flowers.
3. Lily of the Nile, while piled with many friends, waiting to get groomed and moved to another garden, looks like Sigmund the Sea Monster should stay away from the Pacific Coast Highway.
4. Deodar cedar seedlings that grew where they could not live in an industrial yard were relocated to be with friends in a landscape a few years ago. Some, although not all, are now doing well.
5. Beau, the 1967 C10, has a friend also, named Bo, and he is a 1967 C20. Beau helped me bring so much of my old plant material from the Santa Clara Valley. Bo does not get around so much.
6. Rhody is man’s best friend. Like all of his colleagues, he is very committed to his career, which is, of course, his commitment to his colleagues. In this picture, he happily awaits their arrival.
This is the link for Six on Saturday, for anyone else who would like to participate:
It is neither a fern nor a pine. Fern pine, Podocarpus gracilior, can be a tree taller than fifty feet, and half as broad, but is often a shorn shrub or hedge that can be kept less than eight feet tall. Stems are limber enough while young to be espaliered. The finely textured evergreen foliage is somewhat yellowish out in full sun, and darker green in partial shade. Individual leaves are as long as two and a half inches, and less than a quarter inch wide, and hang almost like fat pine needles. Some but not all mature trees can drop a bit of messy fruit with hard pits that are a bit larger than those of cherries. Bark gets distinctively blotched as it ages. The deep roots can be remarkably complaisant with concrete. Outer growth can get damaged by the harshest frosts every few winters or so, or roasted by hot dry heat every few summers.
Since the Dutch Elm Disease (DED) epidemic that killed so many old and stately American elm trees so many years ago, the old fashioned Chinese elm, Ulmus parvifolia, has been unavailable in nurseries. That is why there are only old and middle aged trees, and maybe a few feral seed grown trees. Chinese elm is not bothered much by the disease, but is a vector. ‘Drake’ is a modern DED resistant cultivar, but it has a very different personality, with a more upright and symmetrical structure.
The elegantly lanky trunk and main limbs can be quite curvacious, with distinctively blotched gray and tan bark. The deciduous foliage can be messy in autumn as it falls slowly and may linger through December. The neatly serrate leaves are only about an inch or two long, and half as wide. Mature trees can be more than fifty feet tall.
Japanese maples get all the notoriety. They have such delightful texture and form. Many are proportionate to small spaces, such as atriums. Realistically though, they are overrated and overused. Meanwhile, other maples that work as larger shade trees remain obscure. Norway maple, Acer platanoides, gets broad enough to shade much of an urban garden, but rarely gets to forty feet tall.
Of course, Norway maple has innate limitations. It dislikes arid and harshly warm desert climates. Nor does it like to be too close to the coast. Los Angeles is about as far south as it wants to live. In the Pacific Northwest, it gets much bigger, and develops greedy roots. The non-cultivar species is invasive there. Norway maple defoliates neatly for winter, but then refoliates late in about April.
Almost all local Norway maples are cultivars. ‘Schwedleri’ has richly bronzed foliage. It is rare now, but was a popular street tree in the 1950s. ‘Crimson King’ has richer purplish foliage, but is less vigorous. ‘Drummondii’ displays delightful variegation. The deciduous foliage of Norway maple turns soft brownish yellow or gold for autumn. The palmately lobed leaves may be five inches wide.
This would have been an ideal time for a seasonal update on the little Memorial Tree in Felton Covered Bridge Park. Until recently, it had been healthier and growing more vigorously than it had since it was installed a few years ago. It had survived major accidental damage, and was just beginning to thrive. Sadly […]
Since I began posting my gardening column articles here, and supplementing with blog posts, I have deviated from horticultural topics only a few times. I will now do it again. I had earlier selected a horticultural topic for this post. It will wait for now.
Brent Green, my colleague down south, called me on the telephone to tell me to watch the news. I did so, but only briefly. It was just too crazy. So far, I have made a point of saying nothing about Coronavirus. I said nothing about those who protest the violation of their right to spread disease that will kill others. I mentioned nothing about the racist murderers in Minneapolis.
Now I see that people are senselessly rioting and looting in several cities in America.
The office building of the Canyon News, one of the newspapers that I write for, was clearly visible in the background as police helicopters showed looting of stores on the historic Rodeo Drive in Downtown Beverly Hills, in the region of Los Angeles. Police cars and palm trees were burning. From three hundred and fifty miles away, I can see it online.
This is not demonstration or protest. It is looting. It is mere opportunistic thievery. Those involved are not at all concerned about social justice, their own Communities, or that Black Lives Matter. They are exploiting an already bad situation to plunder what they can get away with.
This is happening in the Community where Brent Green has been planting his Birthday Trees (in quantities that corresponds to his age at the time) in public spaces for the past twenty two years. This is near where Brent Green saved several Canary Island date palms on the Santa Monica Freeway from poachers. This is a region that many people care about.
There really is no such thing as a perfect tree. Some are not quite as messy as others. Some have better structural integrity than others. Some have gentle roots; and some stay proportionate to tight spots. However, without exception, all trees grow, drop leaves, and disperse roots.
This is an important consideration when selecting any tree, and especially when selecting a street tree for the narrow space between the curb and the sidewalk (which is commonly known as a park strip). Even where there is no sidewalk, or where the sidewalk is at the curb, most of the obstacles are the same.
Street trees should have reasonably complaisant roots that should not be likely to damage curbs, sidewalks or roadways, at least for several years. They should naturally develop reasonably high branches. They will need to be pruned higher than trucks that may park at the curb. Street trees must also tolerate harsh exposure.
Wider park strips can of course accommodate larger trees. Those that are only two feet wide or narrower are probably not wide enough for any tree larger than photinia, purple-leaf plum or English hawthorn, which are difficult to prune for clearance over roadways and sidewalks.
Messy leaves, flowers or fruit that might not be a problem within the garden might be more of a problem at the curb. It is not so easy to rake such debris if cars park over it. Trees that are commonly infested with scale or aphid are likely to drop sticky honeydew (scale and aphid poop) onto parked cars.
Unfortunately, those who get street trees do not always get to select them. Many municipalities assign specific trees to specific streets. Some streets have a few trees to choose from. Others have only one option. Home Owners’ Associations (HOAs) decide if and where new trees get planted.
Crape myrtle is probably the most common choice for a new street tree because the roots do not get big enough to damage pavement. However, the canopies are not very big either. They stay too low to be pruned above trucks. Crape myrtle is susceptible to scale infestation that can get bad enough to make sidewalks sticky.
For many years, London plane (sycamore) had been another popular street tree. Unfortunately, the voracious roots can damage pavement within only a few years. The messy foliage discolors and starts to fall before autumn.
Much of my work involves street trees. They need more of my kind of attention than most other trees. They must conform to more restrictive limitations. They endure more abuse. They are the most prominent trees on urban properties. Because some are assets of their respective municipalities, they are more stringently protected by local ordinances than other trees are.
I planted quite a few street trees too. While selecting trees for the medians of San Vicente Boulevard in Los Angeles, we considered the clearance of the lowest limbs above the highest truck traffic, the docility of roots under curbs and pavement, the potential for foliar debris, the resiliency to neglect, and the resistance to pathogens. Those were just some of the major concerns.
We sort of wanted them to look good too.
Ginkgoes, at least modern (fruitless) cultivars, work well as street trees. They are tall and slender, and can be pruned for clearance above streets and sidewalks. Their roots are reasonably complaisant, and take many years to displace concrete. ginkgoes defoliate neatly in autumn, with no debris for the rest of the year. They are resistant to pathogens and tolerant of neglect.
They also look great in their monochromatic but brilliant yellow fall color. (Try to not notice all those utility cables.)
This pair of ginkgoes is in front of an old home in town that was formerly the office of the Los Gatos Weekly Times, before it expanded into the larger Silicon Valley Community Newspapers group. Two decades and one year ago, this was where I dropped off the first of my weekly gardening columns, first as hard copy on paper, then on floppy discs. The trees were smaller then.
One day back in about 1999 or so, I stopped by on my way back from delivering rhododendrons and other horticultural commodities from the farm. I was driving the big delivery box truck. I realized how important adequate clearance is when the truck tore a significant limb from the tree on the left. The tree and I both can attest to the resiliency of the species to such abuse.
Just to be clear, I earned the title of Johnny Appleseed before my colleague Brent Green did. While Brent was secretive about our tree planting projects in Los Angeles, I was not so about our similar projects in Los Gatos. While Brent’s neighbors wondered where their new street trees were coming from, mine read about their new park trees in the Los Gatos Weekly Times.
In fact, the exposure from that article is how I started my weekly gardening column in the same newspaper just a few months later, in October of 1998. Los Gatos is a smaller town than Los Angeles is. Secrecy was not an option. Sadly, our projects in Los Gatos, and then in Scott’s Valley, did not continue. We concentrated our urban tree planting efforts in Mid City Los Angeles.
The tree planting projects that I am referring to are our Birthday Trees that I wrote about last January. As I explain in that article, Brent had been wanting to plant trees in the formerly blank and broad medians of San Vicente Boulevard in Los Angeles. I just happened to be able to supply such trees from those at the farm that got a bit too past their prime to be marketable.
I do not intend to be redundant to that article, but want to share this video, Johnny Appleseed. As much as I hate to admit it, Brent is much more entertaining than I am. (I should later share one of my old videos from Gardening By The Yard, so you can compare.) I should probably look through more of Brent’s old videos to see if there are others that would be interesting.
If I had more time, I would write more about Brent’s work to improve the urban forests of the Los Angeles Region.