Valley Oak

Foggy Oak Morning

‘Foggy Oak Morning’ by Karen Asherah, is another example of the local scenery that I miss while not taking a bus or walking. I drove past this scene for years on my way to work outside of San Martin without ever bothering to take a look at it. This happy tree is a native valley oak, Quercus lobata, like those that had been common throughout the Santa Clara Valley until only about two centuries ago. It is not exactly the sort of shade tree that everyone wants in a compact suburban garden, but is grand enough for large spaces like parks.

Mature specimens may not seem to get as tall as oaks in the Appalachian Mountains, but are actually the largest oaks in North America, and live more than five centuries. The tallest trees are mostly less than seventy feet tall, but can get taller. Trunks of the oldest trees are commonly six feet wide or wider. The distinctively and uniformly furrowed bark is as classically ‘oakish’ as the rounded prominent lobes of the deciduous leaves, and the sculpturally irregular branch structure. Odd stem galls, commonly known as ‘oak apples’, are home to the larvae of tiny wasps that rely on valley oaks for everything they need. Incidentally, Paso Robles, or ‘El Paso de los Robles’ is named for the valley oaks in the area, which Spanish immigrants thought resembled the ‘robles’, the European oaks that inhabit Spain.

More information about ‘Foggy Oak Morning’ can be found at the website of Karen Asherah at karenasherah.com.

Valley Oak

Valley oak is a stately tree.

Native trees are not necessarily the best options for home gardens. Valley oak, Quercus lobata, for example, grows much too large. Old trees can grow more than a hundred feet tall. Although unpopular for new plantings, it sometimes self sows. Also, new landscapes sometimes develop around old trees. Formerly rural trees therefore become urban trees.

Old trees are unfortunately very sensitive to disruption of their surroundings. Grading can severely damage their shallow feeder roots. Irrigation to sustain new landscapes is likely to promote rot of older and larger roots. Trees that should live for centuries can succumb to such damage within decades. Younger trees are fortunately adaptable to landscapes.

Nonetheless, young valley oaks are trees for future generations. Also, they require plenty of space. Although it may take a few centuries, trunks can eventually grow ten feet wide. As they mature, such big trees can make a big mess. The deciduous foliage can shed for weeks instead of days. The pale yellowish brown autumn foliar color is rather mundane. Without excessive irrigation, roots are remarkably complaisant.

Fourteen Weeks

July 12 & October 21

As mentioned in September of last year, comparisons of the growth of the Memorial Tree of Felton Covered Bridge Park are probably more accurate about now, at the end of its growing season, rather than in the middle of July, as I have been conducting them. So, like last year, I did comparisons at both times this year. A minor difference this year from last year is that this secondary comparison is fourteen weeks after the primary comparison instead of seven weeks, and more completely after the Tree has finished noticeable growth for the year. The first pair of comparison pictures compares the Memorial Tree now to July 12. The second pair of comparison pictures compares the Memorial Tree now to August 30 of last year. While the second pair demonstrates approximately how much the Tree has grown during the past year, the first pair demonstrates how much the Tree has grown since July 12. Strangely, most of the growth seems to have occurred after July 12. This is a good indication that the Tree has extended roots below the nearby lawn, so is exploiting irrigation there. (This species typically exhibits most of its growth during spring and early summer while the endemic soil remains moist from winter rain, but then decelerates its growth as the soil dries through summer.)

August 30, 2024 & October 21,2025

Messy Mast

This is the mess that remains after acorns get raked or blown off pavement.

Masting is a technique that oaks and many other genera use to both outsmart and exploit squirrels and other wildlife that both consumes and disperses their seed. For several years, oaks here produce enough acorns to sustain a population of squirrels that is limited by their production of acorns. It may not seem to be very effective, since the squirrels consume almost all of the acorns, leaving very few or none to grow into new trees. Then, every several years, the same oaks collectively produce a ‘mast’, which is a crop of acorns that is too excessive for the limited population of squirrels to consume as thoroughly as they typically do. Squirrels instinctually bury many of the surplus acorns anyway. Because they do not return to dig and eat all of their buried acorns, some acorns grow as new trees. This is how the oaks sustain those who disperse their seed, but also get them to disperse their seed without eating all of it. Mast crops of acorns supposedly typically precede exceptionally rainy winters. So far, the mast this year is only coinciding with a messy situation with drippy nut disease. It is caused by bacterial infection of wounds that are caused by filbert weevils, filbert worms or other insects that damage developing acorns. Consequently, squirrels are ignoring many of the unusually abundant but damaged acorns, leaving icky messes of infected acorns and the goo that they exude. When it eventually arrives, the first rain will make this mess even messier. Later rain should rinse some of it away. It is impossible to know how successful this mast will be, since it is impossible to know how many viable acorns will actually contribute to the abundance and grow later, and how many will merely contribute to this unusually messy mast.

Victim of Gravity

Nature is messy.

What goes up must come down. This elderly and deteriorated Shreve oak may have taken more than a century to go up, and then suddenly came down within only a few seconds. Unfortunately, it was not at all graceful about doing so, as it landed on this unoccupied cabin and a nearby bay tree. The cabin can be repaired. The bay tree needed to be removed with the fallen Shreve oak. Nature is messy like that. Some might say that it is also inconsiderate. Regardless, it can be difficult to live and work with. Most of our landscapes are adjacent to natural ecosystems. All are dominated by big natural trees, including coastal redwood, which is the tallest species of tree in the World. Even if none of the big trees are directly within some of the landscapes, some of such trees are big enough to drop debris or limbs within landscapes that are significant distances away; or worse, they can fall into the landscapes. As much as we try to limit such risks, nature, besides being messy and potentially inconsiderate, is also generally unpredictable. However, one of only a few aspects of nature that is always reliably predictable is gravity.

Oakland

Oregon white oak, Quercus garryana

Oakland, fifty miles north of here, was named for the oaks that formerly inhabited it. Imagine that! Although valley oak, Quercus lobata, is native, and assumed to be the origin of the regional name, coast live oak, Quercus agrifolia, was likely more abundant there at the time.

Of the many other towns in California with horticultural names, a few are also named for unspecified oaks, including del Rey Oaks, Oakdale, Oakley and Thousand Oaks. Encinitas, Live Oak and the Encino neighborhood of Los Angeles are named more specifically for coast live oak. Paso Robles is named more specifically for valley oak.

Oakland and Oakridge are the only two towns that I could find in Oregon that are named for Oaks. I suspect that Oakland is named for Oregon white oak, Quercus garryana, only because that is the most prominent species of oak there. It is also native here, although I am not aware if I have ever encountered it locally. It resembles small specimens of valley oak, which, incidentally, is also known as California white oak.

This picture of a few main limbs of an exemplary specimen of Oregon white oak is from Cabin Creek Rest Stop on Southbound Highway 5, just north of Oakland in Oregon. To me, it looks sort of Californian, like something that, a long time ago, was more prominent in Oakland here in California, on ‘the Bright Side of the Bay’.

Valley Oak

Foggy Oak Morning by Karen Asherah

‘Foggy Oak Morning’ by Karen Asherah, is another example of the local scenery that I miss while not taking a bus or walking. I drove past this scene for years on my way to work outside of San Martin without ever bothering to take a look at it. This happy tree is a native valley oak, Quercus lobata, like those that had been common throughout the Santa Clara Valley until only about two centuries ago. It is not exactly the sort of shade tree that everyone wants in a compact suburban garden, but is grand enough for large spaces like parks.

Mature specimens may not seem to get as tall as oaks in the Appalachian Mountains, but are actually the largest oaks in North America, and live more than five centuries. The tallest trees are mostly less than seventy feet tall, but can get taller. Trunks of the oldest trees are commonly six feet wide or wider. The distinctively and uniformly furrowed bark is as classically ‘oakish’ as the rounded prominent lobes of the deciduous leaves, and the sculpturally irregular branch structure. Odd stem galls, commonly known as ‘oak apples’, are home to the larvae of tiny wasps that rely on valley oaks for everything they need. Incidentally, Paso Robles, or ‘El Paso de los Robles’ is named for the valley oaks in the area, which Spanish immigrants thought resembled the ‘robles’, the European oaks that inhabit Spain.

More information about ‘Foggy Oak Morning’ can be found at the website of Karen Asherah at karenasherah.com.

Valley Oak

‘Foggy Oak Morning’ by Karen Asherah

‘Foggy Oak Morning’ by Karen Asherah, is another example of the local scenery that I miss while not taking a bus or walking. I drove past this scene for years on my way to work outside of San Martin without ever bothering to take a look at it. This happy tree is a native valley oak, Quercus lobata, like those that had been common throughout the Santa Clara Valley until only about two centuries ago. It is not exactly the sort of shade tree that everyone wants in a compact suburban garden, but is grand enough for large spaces like parks.

Mature specimens may not seem to get as tall as oaks in the Appalachian Mountains, but are actually the largest oaks in North America, and live more than five centuries. The tallest trees are mostly less than seventy feet tall, but can get taller. Trunks of the oldest trees are commonly six feet wide or wider. The distinctively and uniformly furrowed bark is as classically ‘oakish’ as the rounded prominent lobes of the deciduous leaves, and the sculpturally irregular branch structure. Odd stem galls, commonly known as ‘oak apples’, are home to the larvae of tiny wasps that rely on valley oaks for everything they need. Incidentally, Paso Robles, or ‘El Paso de los Robles’ is named for the valley oaks in the area, which Spanish immigrants thought resembled the ‘robles’, the European oaks that inhabit Spain.

More information about ‘Foggy Oak Morning’ can be found at the website of Karen Asherah at karenasherah.com.

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.