Coast Live Oak

90522The valley oak of the Sacramento Valley, San Joaquin Valley, and coastal valleys to the west, is the grandest oak of North America. Within the coastal half of that range, and extending down past San Diego, the coat live oak, Quercus agrifolia, is a nearly comparable second grandest. The biggest subjects may be as tall as seventy feet, and nearly as wide, with trunks wider than ten feet!

However, there is significant variability. Trees in forest situations do not get as big, and may stay lower than twenty five feet, with shrubby branch structure. While the biggest can get older than two centuries, smaller trees may not live half as long. The canopies of exposed solitary trees might reach the ground, while more social or sheltered trees are likely to shed lower growth with maturity.

Coast live oaks are typically pretty gnarly, and many have multiple flaring trunks. The dark evergreen leaves are only about an inch or two long, and half as wide, with bristly teeth on convex edges. The narrow inch long acorns can be messy. Roots are very sensitive to excavation and excessive irrigation. Sudden Oak Death Syndrome prevents new trees for getting planted in many regions.


Mighty Oaks From Little Acorns

90522thumbOak, which might seem to be obvious to many of us, was identified by the Arbor Day Foundation as the People’s Choice for American’s National Tree. We certainly like our redwoods and exotic palms in California. Quaking aspen and blue spruce are probably favorites in Colorado. Sugar maple must be the most popular in Vermont. Yet, everyone appreciates the mighty American oaks.

Connecticut, Georgia, Illinois, Iowa, Maryland, New Jersey and the District of Columbia each have an oak as the official state tree. ‘Oak’ is one of the more traditional names for streets and roads throughout America. Just in California, at least eight towns are named after oaks, both in English and Spanish. Oaks put the ‘oak’ in Oaklahoma! (Oakay, maybe that last one is an exaggeration.)

So, now that we know that oak is what most Americans want to be the National Tree, does anyone know what species the oak should be? Well, that will take a bit more work. There are so many in America. There are too many to select from just in California! They are each so unique too. Some grow into grand trees. Others are shrubby scrub oaks. They might be deciduous or evergreen.

It is important to be aware that, just because oaks are the most popular trees in America, they are not necessarily appropriate for home gardens. Some, particularly in California, are best in the wild outside of landscaped areas. Some get too big. Some are too messy with acorns and leaves that fall slowly for a long time, either evergreen or deciduous. Some are susceptible to disease.

It is also important to be aware that big mature oaks, as rugged as the seem to be, are remarkably sensitive to modifications to their environment. Wild oaks that matured in areas that were not landscaped can succumb to rot in only a few years if the ground below them gets landscaped and regularly watered. Oaks planted into new landscapes adapt to the watering they get while young.

For landscapes that can accommodate them, oaks are grand and elegant shade trees that last a lifetime. There are many good reasons for their popularity.


Apologies for posting tomorrow’s article today. Today’s article will be posted tomorrow.

Not My Style

P90202KThere is no shortage of artistic pictures online and within the context of gardening blogs. Some really are fascinating. I particularly like those that show the weather in far away and mythical lands like Colorado, Chicago, North Carolina, Australia, Oklahoma, New Zealand, Austin, and South Africa. Then there are the cats, dogs, hens, horses, pigs, and a few others that are not so entertaining. The close ups of flowers, fruits, leaves, mushrooms and any variety of odds and ends are amusing if they are not immediately recognizable. Yet, all these pictures are not my style. I am not the artistic sort.

I will try though. This shiny chestnut brown acorn half shell just looked like something that I should get a picture of. It was just laying there on the big sycamore leaf as if it were on display. The interior is even shinier and more richly colored than the exterior, although I did not turn it over to confirm. I am just guessing from my experience with other acorns.

The sycamore that provided the leaf is a California sycamore, Platanus racemosa.

I could not identify the species of the oak that provided the acorn. I am pretty certain that it is not from a coast live oak, valley oak, black oak or tanoak; respectively, Quercus agrifolia, Quercus lobata, Quercus kelogii or (Notho)Lithocarpus densiflorus. There are not many other options. I suspect that it could be from a canyon live oak or Shreve oak; respectively, Quercus chrysolepis or Quercus parvula ‘Shrevei’. Neither produces acorns that are typically as round as this one was.

Nor could I identify the species of squirrel, rat, raccoon, crow or whatever unknown animal dropped it.

Well, perhaps this is why I am not the artistic sort. I am instead the technical sort.

California Black Oak

81003The most popular hardwood in California is essentially unavailable in nurseries. California black oak, Quercus kelloggii, provides between a quarter and a third of the hardwood timber harvested in California. One would not know it by its sporadic appearance within mixed forests of the Coastal Ranges. It is much more common in the Sierra Nevada, which might be why no one grows it.

Mature trees can top out at thirty feet with broad canopies if well exposed, or might be more than seventy feet tall and relatively slender if they must compete with other trees. The biggest trees are more than a hundred feet tall. The sculptural trunks are usually less then four feet wide. Trunks of old trees are commonly rotten inside. Gray and smooth young bark gets rough and dark with age.

The distinctively lobed deciduous leaves of California black oak are not much more than four inches long. They can get nearly twice as long on the most vigorous growth, or where shaded. The dark green foliage will slowly turn brown or yellow through autumn, and then defoliate through winter. It can turn a brighter yellow or orange, but then defoliates faster, if the weather gets cool fast.

Illegally Planting!

P80902K“ . . . others illegally planting whatever they wish . . . illegally.” Someone actually said that about the installation of our little Memorial Tree in Felton Covered Bridge Park. It was within the context of a review of the Park on Facebook, written by someone who has not stopped complaining about Felton since she moved here. It was forwarded to me quite some time ago by someone who documents and files such information that is relevant to hate crimes, and what is now known as ‘hate speech’, which is another completely different topic that we can not get involved with here.

Technically, it is accurate. The tree was planted without a permit, and does not comply with the standards of Santa Cruz County Parks. Compliance would have been quite an expensive imposition. It would have required an expensive #15 (15 gallon) tree, outfitted with lodgepole stakes and straps. The overworked gardener would have needed to take time from his busy schedule to install it. Because the irrigation system to the site is now defunct, the gardener would have needed to irrigate the tree until it got established. It was easier, much less expensive, more horticulturally correct, and socially responsible for us install the tree and maintain it on our own. Call 911 if you must.

There are of course reasons why we should not plant trees or other plant material in parks and public places. We do not want to make more work for gardeners, interfere with the landscape plan, or add plants that are inappropriate to the situation. This Memorial Tree happened to have been planted with the supervision of a horticulturist and arborist (me), on the exact spot where another oak that was installed with the original landscape had been knocked down by a car. Otherwise, in most places in Felton Covered Park, vegetation management, including the removal of large volumes of biomass and invasive exotic specie, should be the priority. (Unfortunately, the overgrowth of invasive exotics is mostly within a protected environmentally sensitive riparian zone.)

The little Memorial Tree has quite a history, even though it is still a baby. I do not want to post links to all the other updates about it, but I can post this link to another article that contains another link to others . . . Oh, you can figure it out if you like: .


P80902KThere is NO news regarding the tiny Memorial Tree in Felton Covered Bridge Park that I so frequently provide updates for. It did not do much this year. I probably already mentioned this when it was busy not doing much in spring. It is in a difficult situation, where too many dogs do what dogs do to tiny valley oaks that are busy not doing much more than trying to survive without regular watering, out in a harshly exposed island in a parking lot. Once it gets going, it should do fine. It is only slow now, but is not unhealthy. It is doing exactly what it should be doing this time of year. By late autumn, it will try to defoliate. Valley oaks are never in a rush for that.P80902K+
This angel’s trumpet is more interesting because it was seemingly deceased. As you can see, it is trying to recover . . . just in time for autumn. Unfortunately, there will not be sufficient time and warm weather for it to mature enough for the new stems to survive even a mild frost next winter. At least it will get a bit of time to recharge the roots so that it can regenerate a bit more vigorously next spring.
There is of course the possibility that it will not get frosted too severely in winter. It is somewhat sheltered by the canopies of nearby trees. We may even try to protect it under a box on the coldest nights.
Realistically though, the loss of such minor growth would not hurt it much. As it matures, it will likely lose much or most of its outer foliar growth annually each winter, and then replace it with new growth each spring. The priority for it now, or at least next spring, is to develop substantial stems that are above where ‘gardeners’ will cut it down with a weed whacker. Once it does that, it will have a relatively permanent framework of resilient trunks that it can get frosted back to.
The main problem since it was installed was not the frost, but unskilled labor with weed whackers. No matter how emphatically we explain to the ‘gardener’ that it is not a weed, his crew cuts it down a few times annually when no one is there to stop them.P80902K++
Naked ladies continue to bloom all over the region. These happen to be in the parking lot of Felton Covered Bridge Park. Several that were surplus in a neighbor’s garden were planted in the corners of the various islands. Unfortunately, because of their locations, most of their flower stalks get trampled and broken off. The picture below shows how exposed they are within an area of substantial traffic. The foliage that develops later does considerably better. It is too substantial to be trampled and ruined completely, and it gets a bit more substantial every year. However, the substantial foliage is not here yet to prevent the flower stalks from getting trampled.P80902K+++
By the way, if you think that I wrote this post because of the (former) lack of a horticulturally oriented topic for today, you are correct.

Cork Oak

71115Like redwoods, the cork oak, Quercus suber, is a ‘pyrophyte’, which means that it survives forest fires that burn off competing vegetation. The trunks and main limbs are insulated with a very thick bark. Only the foliage and smaller stems burn off. After a fire, the upper limbs of cork oak regenerate new foliage while other less fortunate plants start over from their roots or seed at ground level.

The thick bark is really what cork oak is grown for. It is used for corks, gaskets, flooring, notice boards, cricket ball cores and too many other products to list. It is also quite handsome on the stout trunks and limbs of landscape trees. If only the acorns were not so messy, cork oak would be a nice drought tolerant street tree with complaisant roots. The hazy evergreen leaves are about two inches long. Old trees eventually get almost fifty feet tall.