Valley Oak

Valley oak is the grandest of oaks.

From the north end of the Sacramento Valley to the San Fernando Valley, the valley oak, Quercus lobata, is among the most familiar and distinctive of native oaks. It is the largest oak of North America, reaching more than a hundred feet tall with trunks as wide as ten feet, which is why it is rare in urban gardens. The hundred fifty foot tall ‘Henley Oak’ of Covelo is the tallest hardwood tree in North America. The oldest trees are about six centuries old.

The two or three inch long leaves have deep and round lobes. The foliage turns only dingy yellow and then brown in autumn, and can be messy as it continues to fall through early winter, particularly since the trees have such big canopies. The gnarly limbs are strikingly sculptural while bare through the rest of winter. The gray bark is evenly furrowed.

Incidentally, Oakland, Thousand Oaks, Paso Robles and various other communities within their range are named for valley oaks. (‘Roble’ is the Spanish name.)

Valley Oak

Valley oak is the grandest oak.

From the northern end of the Sacramento Valley to Santa Catalina Island, valley oak, Quercus lobata, is as Californian as Valley Girl. It inhabits mixed riparian forests and low hillsides up to about 2,000 feet, but prefers alluvial valley meadows in between. Although unpopular for landscaping, it sometimes self sows into home gardens. New landscapes sometimes develop around old trees.

Valley oak is one of the biggest of oaks, and the tallest oak of North America. Mature trees can be more than a hundred feet tall, and several centuries old. Trunks may be more than ten feet wide. Such big trees make big messes of acorns and deciduous foliage, which shed for weeks. Unfortunately, old valley oaks within new landscapes are susceptible to spontaneous limb failure and rot.

Where space is sufficient, new valley oaks are for future generations. They develop their distinctively sculptural branch structure slowly through several decades. If irrigation is not excessive, roots are remarkably complaisant. The evenly furrowed gray bark is rustically distinguished. The elegantly lobed leaves are about three inches long and half as wide. Yellowish autumn color is subdued.

Camphor Tree

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Camphor trees have stout branch structure.

The best camphor trees, Cinnamomum camphora, are in parks and other spacious landscapes. Such trees have sufficient room for their broad canopies. Although they do not grow rapidly, they eventually get quite large, and perhaps too massive for confined urban gardens. Some of the older local trees are nearly fifty feet tall, and nearly as broad. They have potential to get much bigger.

Camphor trees excel as shade trees. Their light green or perhaps yellowish evergreen foliage is quite dense. Shade of groups of trees or large trees with low canopies inhibits the growth of lawn grass. Also, roots are likely to eventually elevate lawn or other features that are close to the trunks. Foliar canopies are billowy, but can be lopsided, especially in windy or partly shaded situations.

Trunks and main limbs of camphor trees are rather stout, and can be rather sculptural. Trees should be pruned for clearance while young. Otherwise, obtrusively low limbs can become prominent components of the canopies. The tan bark is distinctively checkered. It darkens handsomely with rain. All parts of camphor tree are quite aromatic. Frass from spring bloom can be slightly messy.

California Sycamore

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California sycamore is a stately native.

California sycamore, Platanus racemosa, is a riparian species that wants to be a chaparral species. It seems to passively mingle with valley oaks and coast live oaks in chaparral regions. Yet, it stays close to rivers, creeks, arroyos, or low spots where water drains from winter rain. California sycamore does not follow waterways far up into forests though, as if it dislikes the deeper shade.

In urban situations, California sycamore is best for large scale landscapes, such as parks or medians of broad boulevards. It is complaisant enough for smaller landscapes, and tends to disperse roots too deeply to damage pavement. However, it grows so fast and so very big. Mature trees get to a hundred feet tall. Massive trunks are picturesquely irregular, with mottled tan and gray bark.

All the deciduous foliage generated by such large trees is generous with shade for summer, but stingy with color for autumn. Defoliation starts early and continues late, so is messy for a long time. Foliar tomentum (fuzz) is irritating to the skin, and much worse if inhaled. Anthracnose often deprives trees of their first phase of foliage in early spring. Although harmless, it makes another mess.

California Sycamore

41119Out in rural chaparral regions, where water is scarce, the big and bold California sycamore, Platanus racemosa, somehow seems to find the spots where groundwater is not too far below the surface of the soil. It is technically a riparian tree, that is just as comfortable competing with cottonwoods and willows along forested rivers and floodplains. It eventually get too big and messy for refined urban gardens, but is somewhat popular nonetheless.

The bulky trunks and limbs are just too striking to ignore, especially as trees defoliate to expose the mottled beige and gray bark. Trunks are typically leaning and irregularly sculptural. Many trees have multiple trunks. The biggest trees are a hundred feet tall. The big palmately lobed leaves can be eight inches wide, but unfortunately do not color well in autumn. The foliar tomentum (fuzz) can be irritating to the skin when leaves need to be raked. Athracnose causes much of the early spring foliage to fall, and sometimes distorts and discolors later summer foliage.

Cottonwood

90724Several native species and varieties of poplar are known collectively as cottonwood. Not many are actually planted. They just have a sneaky way of appearing in well watered parts of the garden that are as damp as the riparian areas that they naturally inhabit. Only Fremont cottonwood, Populus fremontii, gets planted, rarely, and only in big spaces that can accommodate its grand scale.

Although too big and too thirsty for most refined landscapes, cottonwoods work well for shade or erosion control in big parks. However, they need to be in a lawn or irrigated landscape if they are not close enough to riparian areas to disperse their roots into soil that is somewhat moist through most of the year. Even in riparian situations, young trees need irrigation until their roots disperse.

Cottonwoods grow fast and big, with aggressive and potentially destructive roots. They should not be planted too close to pavement or septic systems. Vigorous trees might sometimes need to be pruned to reduce excessive weight. Big trees might grow to nearly a hundred feet tall, with wide canopies. Bark is handsomely furrowed with age. The deciduous foliage turns yellow in autumn.

Small Tree In A Big Park

P71006How did the Featherstone Tree survive? (See: https://tonytomeo.wordpress.com/2017/10/05/big-tree-in-a-small-town/.) It was planted on the edge of a busy highway where heavy loads of lumber were driven by oxen, at a time when society was more interested in harvesting trees than preserving them. Yet, after more than a century, it is still here.

The Scofield Tree is a very small valley oak in an island of a parking lot at Felton Covered Bridge Park, just across the San Lorenzo River from the Featherstone Tree. In a few centuries, it might be comparable to the big valley oak that was recently cut down across the road (See https://tonytomeo.wordpress.com/2017/09/11/goodbye-to-an-old-friend/.) It is a good choice for this location because it develops a remarkably complaisant root system for such a large tree, and it is a native, so does not need to be watered.

However, it is the fourth tree to be planted here. The original California black oak that was planted when volunteers from the Community built the park years ago did not last long before getting run over by a car. It was not replaced until a small Eastern redcedar was planted on New Year’s Day of 2013. That tree was dead and crispy by summer. A bigleaf maple was planted the following winter, and sort of survived through the year, only to die the following winter. It was too late in winter to plant anything new that year, so the tiny valley oak was planted late in 2015.

Although tiny, it had a nice root system, which was more than the two bare-root trees before it had. The hope was that if it could survive getting peed on by dogs long enough to disperse roots, it would be fine. It started to foliate the following spring, only to get much of the bark gouged away by a ‘gardener’ with a weed whacker. The poor tree nearly died, but somehow survived and started to recover. However, it did not recover fast enough to get ahead of the dog pee. It really seemed to be struggling through this year, and is now getting ready to defoliate for autumn. It really needs to get some height next year. Small trees are just too vulnerable to all that goes on in a park.

Each of the redwood trees around the perimeter of Felton Covered Bridge Park is a memorial tree, sponsored by friends or family of the deceased. An additional sweetgum tree is a memorial tree for a French bulldog. Some of the trees are outfitted with memorial plaques. The tiny valley is named the Scofield Tree for an old friend of the Community, Jeff Scofield, who passed away in the spring after the tree was planted; but it is really a memorial tree for a few people who passed away within a few years of that time. The Scofield Tree was sponsored and planted for the deceased by Felton League, an informal group of displaced and socially disadvantaged people of Felton, and their friends. Their Facebook page can be found at https://www.facebook.com/Felton-League-520645548069493/.

Perhaps what is written now about the Scofield Tree will eventually become part of the history of Felton, and be summarized on a plaque like the one on the Featherstone Tree. It would be excellent enough if the Scofield Tree simply does what good treed do in a park for a few more centuries.

California Sycamore

70913No other big tree has trunks as sculptural as those of the California sycamore, Platanus racemosa. They bend and groove so irregularly, seemingly without direction, that it is a wonder that old trees in the wild eventually get a hundred feet tall. Some trees have a few trunks. The mottled beige bark is quite striking both in the shade of the broad canopy, and while trees are bare in winter.

California sycamore is a surprisingly well behaved street tree, but only for a few decades or so. The roots are quite complaisant. The main problem is that the bulky trunk eventually gets wider than the parkstrip. Another problem is that such a big tree drops a huge volume of foliage in autumn, and then again in spring as anthracnose ruins much of the new foliage. The big palmate leaves are about eight inches wide, and covered with tomentum (fuzz) that is irritating to the skin.