Spicing Up Your Forest

by Eric Larusson

Aspen and pine may be the most popular tree and screening choices for Tahoe homeowners, but your garden can find balance with a variety of colors and textures.

To the chagrin of my family and friends, I like to talk about plants… all the time. It’s definitely a social handicap. In addition, I’ll stop the car in rain or snow or blazing heat to jump out and see a plant. Why? I’m rewarded by the mental images I carry with me of “perfect specimens,” perhaps a plant that I saw in the middle of the Utah backcountry or in southern British Columbia.

Trees, in particular, have deep roots in my memory. When I’m asked about Dogwood, for example, a flood of images fills my mind screen. It’s therefore a daunting task to write about the many alternative trees appropriate to our region without the article sounding like a travelogue… but I’ll do my best.

I don’t need to paint a mental picture for you of the trees that everyone grows up here. Quaking Aspen, for example, is a beautiful tree that wants to take over the temperate portions of the globe, and has the potential to succeed. We’ve helped it along and now have Aspen popping up even in lawns! Then there’s the Blue Spruce (the blue is an adaptation to heat and drought), a great living Christmas tree that is planted in many gardens, grows very quickly and soon permeates the man-made landscape. These and the many other species common to Sierra yards are excellent landscape plants, their numbers a testament to their persistence in our climate. Here are a few other under-appreciated plants (and some of my memories of them).

Western River Birch (Betula occidentalis fontinalis) was first given a Latin name by Lewis and Clark; they thought it was a variety of the Northeastern Paper Birch. Like the Paper Birch, the tree is fontinal — always growing near water — though it doesn’t have white bark, but rather one of deep copper color. The tree was planted throughout the North Shore and Truckee during the 1980s by Alpine Plants, owned by landscape architect Brent Thrams.

Western River Birches grow quickly, provide dense screening and hold up to snow from the roofs of two-story houses dumping into the too-narrow space between them — the case in Tahoe Donner and other neighborhoods with long narrow lots. Their fall colors range from gold to deep maroon. I’ve seen them grow nearly 30 feet tall on streamsides along US 395 in the southern Sierra, and throughout the southwestern Rockies. My business partner, Sarah Trebilcock, has seen these trees grow at nearly 10,000 feet elevation in the Sierra and in creek bottoms below huge avalanche zones — the Birch were dense and stately while the Aspen in the same area were crumpled. The Sierra version of the plant is difficult to transplant, whereas the Rocky Mountain plants, partially because of their summer rains, are better adapted to gardens.

Oak is a tree that everyone knows, and growing these long-lived plants is a tribute to the future. The Tahoe-Truckee area has Huckleberry Oak (Quercus vaccinifolia), Canyon Live Oak (Q. chrysolepis) and occasionally hybrids of the two. While beautiful and evergreen, these two natives are temperamental in their watering and soil requirements and very slow-growing. Gambel’s Oak (Quercus gambelii) is a faster-growing Rocky Mountain native that adapts well to gardens. I’ve seen specimens in Mesa Verde over 40 feet tall and acres of these trees creating a “magic carpet” of fall colors on mountainsides. I came across a couple of old-timers last summer in Ouray, Colorado near 10,000-foot elevation that had huge trunks and looked like they were going to reach out and grab you. I’ve grown this Oak from both seed and from plants and they’ve grown quickly and held up well to our abusive Sierra winters.

Cornelian Cherry (Cornus mas) is probably the most reliable tree-form of Dogwood you can grow. It has nice pink fall colors, less-than-showy yellow flowers in March and even produces red cherry-like fruit, which are edible, but super-pucker tart! The plant is well-behaved in the garden and grows to about 15 feet in our climate. The one in my front yard is my favorite specimen, where it makes a nice screen from my walkway to the street.

Modoc Cypress (Cupressus bakeri) is a drought-tolerant evergreen from the cold Modoc plateau of Oregon. I have always liked the plated cones (they are perfect throwing size). They look like big green balls out in the landscapes north of Alturas, California. While similar in shape and size to the Western Juniper (Juniperus occidentalis), this plant is faster-growing, more graceful, and better suited to gardens. Large individuals have been found well over 50 feet tall but I wouldn’t expect one to get much over 30 feet here.

One of my favorite native shrubs is the Western Mountain Ash (Sorbus scopulina). It has unique leaves, spring flowers, bright fall colors and excellent berry display. The native is slow-growing and temperamental, but the European Mountain Ash (Sorbus aucuparia) is faster-growing with all the attributes of the native. It does experience some difficulties here, however. The bare trunks suffer from sun scald and freeze cracking and Flickers, Sapsuckers and Woodpeckers love its sweet sap. But when the birds eventually girdle the trees, they begin to sprout up and grow into dense multi-trunk small trees — one of my favorite screening plants for sun or shade. Once established and fruiting, they tend to seed themselves around the garden, although I’ve enjoyed moving them to needed locations along my property line. Mountain Ashes love acid soil, acid fertilizers and rich fungal compost. I mulch mine with many inches of pine needles raked off the lawn each spring and fall.

Sargent Crabapple (Malus sargentii) is a species of crabapple well suited to screening. It usually grows only eight feet tall but it spreads to ten or more feet wide. In the book Siftings, Prairie Style landscape architect and conservationist Jens Jensen speaks of broad thickets of crabapples underplanted with violets, with wild clematis clinging to the branches. “The whole composition represents a friendly home and a friendly garden… no voice of arrogance or dominance disturbs it.” Shrubby feral apple trees can be found along many old roads around Tahoe and Truckee, grown from discarded apple cores — any plant that can thrive and bloom in the sand and snow thrown from our roads is certainly deserving of a place in our gardens! Crabapples are not native, but part of the prairie influence that surrounds us, including old lilacs, peonies and Harrison’s yellow roses. For a native feel that is similar to that of Sargent Crabapple, use Serviceberry (Amelanchier alnifolia) underplanted with wild strawberry, western columbine and blue lupine.

Eric Larusson is co-owner of Villager Nursery in Truckee, which has handouts on many topics and conducts regular gardening classes. For more information, visit www.villagernursery.com or call (530) 587-0771.