Quaking Aspen in California’s Eastern Sierra

On the eastern side of the Sierra, ribbons of brilliant gold flow down the mountainside. The color can be seen from miles away.  Meadows spread wide covered with vivid yellow-leafed Aspen quaking in a fall breeze. It's the height of the fall foliage season in this part of California.

As I drove down Hwy 89 south of Lake Tahoe past Markleeville and then over Monitor Pass to Hwy 395 each stand of aspen seemed to glow brighter than the last. I wondered if they would be as beautiful for future generations or if our impact on the environment would cause these glorious trees to change in any way.

Quaking aspen (Populua tremuloides) is the most widespread tree species in North America. It provides food for foraging animals and habitat for wildlife. It also acts as a fuel break and retains much more water in the environment than do most conifer species.

High mountain systems, such as the Sierra Nevada, are uniquely sensitive to anticipated global climate changes and act as canaries in the coal mine to provide early signals of significant climate-driven changes. Research in the Sierra Nevada by Pacific Southwest Research Station, which is a USDA Forest Service research organization, shows how vegetation has responded to climate in the past and indicates changes than might be coming in the future over the next decade.

Climate has a profound influence in shaping our environment and natural resources. By looking at tree-ring records of living and ancient wood and pollen lake sediments present climate can be compared to these historic patterns to show climate changes.

Research indicates a complex, unpredictable future for aspen in the West, where increased drought, ozone and insect outbreaks will compete with carbon dioxide fertilization and warmer soils, with unknown cumulative effects. Aspen are valuable in providing moisture in the landscape and habitat and food for wildlife. They are vulnerable in the face of global warming and climate change. Hopefully, we will not lose this wonderful tree in California.

If you're from a part of the country where these trees are native and you miss their fall color there is a new cultivar of Improved Quaking Aspen developed for mild winter areas like ours. It provides a splash of color for areas that are naturally moist like a natural stream or a high water table. They grow 20-30 feet tall and 15 feet wide and spread by underground roots to form a stand.

Fall Color Trees for the Santa Cruz Mountains

Walking around my neighborhood I see neon red fall foliage at every turn. Japanese maples covered with vivid red, bright orange or yellow leaves steal the scene wherever they grow. Surrounded by greenery Canadian redbud now pop with burgundy and yellow color. Flowering dogwood look like they're on fire. Because we live among so many trees and shrubs that stay evergreen in winter, fall color is especially important for us. What plants put on a good show in our area?

We are all familiar with the brilliant fall color of Japanese maples. Bloodgood is probably the single most popular upright purple-leaved variety seen in gardens. Beautiful in color and form, it's easy to grow and fits nicely in the smaller garden. Mine is covered with glowing red foliage now even though it grows year round in the shade.

My Coral Bark Japanese maple has had glowing golden and red foliage since early September. It's one of the earliest to start coloring in fall and make quite a statement in the garden when combined with warm-toned plants like heauchere 'Creme Brulee'.  I love this tree as it grows more upright and looks great near an entry as an accent. That luminous spark of lighter color is beautiful next to the deep reds of the other trees.

I surveyed some fellow designers for their favorite fall color varieties and found another Japanese maple favored not only for fall foliage color but the purple leaf color maintained during the summer even in hot situations. Called Red Emperor it's a moderate grower to 15 ft tall and wide. Like other Japanese maples it needs regular watering-weekly or more often in extreme heat especially during the first growing season to establish a deep, extensive root system. Watering can be reduced after establishment. Keeping mulch over the root zone is vitally important in our hot summers. Japanese maples look dramatic when planted with Japanese Forest grass, deer fern, flowering cherry and coral Bells.

Another favorite of mine for fall color is Crape Myrtle. You see them covered with large, colorful flowers starting in summer and lasting through fall. They are planted everywhere for good reason. Easy to grow and fast growing they take heat or cool coastal conditions. They are not fussy about soil and ask only for deep but infrequent watering. As if the flower color weren't enough to attract you, they absolutely glow in the fall with shades of red, orange and yellow. I'm partial to purple flowers so varieties like Catawba, Muskogee and Zuni top my list. Watermelon red and other bright red flowering varieties are also popular.

A great tree for the gardener interested in edibles is the Fuyu persimmon. This beautiful small tree is ornamental with glossy green leaves and also offers a dramatic fall display in shades of yellow, orange and red. Bright orange fruit begins to develop in late October and clings to bare branches usually through December. The tree looks more like it's covered with holiday ornaments than fruit.

Chinese pistache is a good tree for a patio, lawn or streetside. They can get by with almost no water but will tolerate lawn watering if drainage is good. Luminous orange to red fall foliage color is reliable even in mild winter areas. They are usually grown from seedlings.  When you buy one, it might be either male or female but a male tree without berries will develop better color.

Other trees with vivid autumn color that also do well in our area include red maples like October Glory and Autumn blaze, liquidamber, ginkgo, ornamental pear, cherry or crabapple, dogwood, goldenrain, locust, katsura, oak, redbud, sumac. All add to the fall drama of the landscape.
 
Now through late fall is a good time to shop for trees that change colors because you can see in person just what shade of crimson, orange, scarlet or gold they will be. I'm off to the eastern side of the Sierra to see for myself the Black oak and Quaking aspen fall color.
 

Fall Wildflowers & October to-do’s

Above the clear turquoise water of the Big Sur coastline, wildflowers still bloom in October. Bright orange Sticky Monkeyflower meander among a carpet of rosy blooming California Buckwheat. Deep orange California fuchsia flower on hillsides alongside the bright white flower heads of yarrow. They make a striking combination. Under the partial shade of pine trees lavender Seaside Daisy explode with color. Even poison oak contributes deep rusty-red tones to the landscape making it easier to identify and avoid. This wild land offers lessons and ideas to make our own gardens more beautiful.

Big Sur has areas of chaparral, oak and pine woodlands, riparian or streamside woodlands and redwood-tanbark-oak woodlands. Nearly half of all the flora of California grows here and many northern and southern California plants mix in this unique location. . Only in Big Sur will redwoods and yuccas thrive together. The look is startling. Certainly not a combination you would think of for your own garden.

Near McWay Falls on Hwy 1, fragments of an elaborate stone house still remain along with some of the landscaping. Christopher McWay and his wife Rachel settled the area in the late 19th century.The land passed through several owners until former U.S. House of Representative Lathrop Brown and his wife Helen acquired it and built a beautiful stone structure overlooking McWay Cove. The house was torn down 50 years ago but many of the landscape plants still thrive after all these years.  Hardy pittosporum eugenoides have survived without any supplemental watering. A huge stand of blooming Naked Ladies covers the rocky slope. We all know what survivors these bulbs are. Tall Mexican palms and ornamental trees surround the fragments of stone staircases and walls reminding us that nature will endure.

What allows all plants to thrive in their environment is the simple set of conditions that they like. It's nearly impossible to grow ferns in the hot sun around here and don't even think about trying a California fuchsia in the shade. Soil is important, too. Rich, moist soil is perfect for wild ginger but gravelly, well drained soil works best for Five-fingered ferns. Match the right plant with the right spot and you'll have success every time. Big Sur is a chock full of success stories.

Here are more tips for early fall in the garden.

Fall is not a good time for major pruning.  Wounds heal slowly, leaving them more susceptible to disease.  As a general rule, don't prune when leaves are falling or forming.  Wait to prune most trees until late in the dormant season or in late spring after leaves and needles form.  To avoid sap flow on birches and maples, prune after leaves mature.  

Do refresh perennials, such as butterfly bush, salvia and yarrow by cutting a third to half of their growth.

Rake leaves– compost or put in your green can. If large leaves are left in place they will mat down and set up fungal problems come spring.
 

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