Ask Mr. Smarty Plants

Let’s start with a list of native plants for California and your tree height requirements. Take a look at the Native Plant Database on the www.wildflower.org website and put in the following search criteria: State = California, habit = tree, duration = perennial, light requirement = full sun, soil moisture = moist, height = 12-36 feet. This search reveals 10 native trees. You can further refine your search into deciduous or evergreen foliage subgroups. Here are some suggestions from the search:

Acer glabrum var. douglasii (Douglas Maple) From Hansen's Northwest Native Plant Database: Douglas Maple is a superbly contoured shrub or small tree. Its narrow, elliptical crown is comprised of slight branches reaching upright towards the skies.

Slim, young twigs are smooth and reddish, but as the plant matures the thin bark becomes grayish or brown. Deep emerald green leaves with pale undersides are supported by elongated wine-colored petioles.

Tolerance and beauty are Douglas Maple’s ornamental virtues. It is chosen for its ability to flourish in moist as well as xeric soils, its tolerance of both sunny and shady sites, and its striking autumn pageant. this plant is a highly valued ornamental that embraces a multitude of landscape conditions. Tolerant of full sun and shade, the species succeeds even with drought and high temperatures. Low to moderate water use makes this species an attractive addition to un-irrigated landscapes.

The moderate grower gains about 1 foot per year. It prefers soils to be slightly acidic to slightly basic, but is really not very finicky about soil pH levels. Douglas Maple is considered hardy to Zone 5. Plant the seedling in a sunny spot for bright autumn colors. If you notice some chlorotic mottling on the leaves, the plant is probably suffering from an iron deficiency in the soil.

Alnus incana (Gray alder) Speckled alder is a tall shrub or small tree, 20-35 ft. tall, with multiple, crooked, leggy trunks. Bent in a wide curve at their base, the trunks become upright and picturesque. Deciduous leaves are rounded and coarsely toothed, remaining dark-green in autumn. The flower is a purplish-red catkin and the fruit is a woody cone. Alnus rugosa and Alnus tenuifolia are usually considered subspecies. Fast-growing and flood tolerant, this species is short-lived, rarely exceeding 40 years. It can be thicket-forming and provides erosion control along watercourses in the mountains. Alders fix nitrogen and thus serve as nutrient-giving pioneers in reclamation projects.

Betula occidentalis (Mountain birch) Water birch or mountain birch is a 20-30 ft., multi-trunked tree with shiny, reddish-brown bark. Its delicate, graceful appearance is created by slender, spreading, pendulous branches. Shrub or small tree with rounded crown of spreading and drooping branches, usually forming clumps and often in thickets. The red color of the branches and twigs creates the same winter effect as red-twigged dogwoods. The small, deciduous leaves are bright green above and yellow-green beneath becoming bright yellow in fall.

This uncommon but widespread species is the only native birch in the Southwest and the southern Rocky Mountains. Sheep and goats browse the foliage.

Do not prune until summer when the sap has stopped flowing. Susceptible to borers, aphids, and other problems when grown in dry soil. Does not cast heavy shade, permitting underplanting.

Chilopsis linearis (Desert willow) Desert-willow is a 15-40 ft., slender-twigged, small tree or large shrub, often with leaning, twisting trunk and open, spreading crown. Leaves are deciduous, willow-like, light green, both opposite and alternate, 4–12 inches long and 1/3 inch wide. The blossom is funnel-shaped, 1–1 1/2 inches long, spreading at the opening into 5 ruffled, petal-like lobes. The flower is dark pink or purple, often with white or yellow and purple streaks within the throat. The catalpa-like flowers are borne in terminal racemes. By early autumn, the violet-scented flowers, which appear after summer rains, are replaced by slender seedpods, 6–10 inches long, which remain dangling from the branches and serve to identify the tree after the flowers are gone. Mostly blooms heaviest May to June but will continue to bloom sporadically throughout the warm season after rains. Flower color ranges from solid white or muted pink to darker rose and purple, as well as two-toned combinations of those colors. Throat often yellow-tinged. Many cultivars available with varying flower colors. Well-drained limestone soils preferred, but also does well in sands, loams, clays, caliches, granitic, and rocky soils. Minimal organic content the norm. Allow to dry out between waterings, as this will encourage more extensive waves of blooms. Avoid excessive water and fertilizer, as that can lead to overly rapid growth, fewer blooms, and a weaker plant. Prolonged saturation can result in rot. Won’t grow as fast or get as large in clay soil but won’t suffer there either. Can be drought-deciduous in some regions. Can survive temperatures as low as 10 degrees F.

Cornus nuttallii (Pacific Dogwood) Tree with dense, conical or rounded crown of often horizontal branches and with beautiful white flower clusters. This is the west coast edition of Cornus florida. It is a 15-40 ft., single- or multi-trunked tree or shrub with a spreading crown and large, showy, creamy white blossoms sometimes flushed with pink. Graceful, horizontal-tiered branching; orange to red fruits; and yellow-orange, fall foliage are other landscape attributes. Pacific flowering dogwood is deciduous.

Pacific Dogwood is one of the most handsome native ornamental trees on the Pacific Coast, with very showy flowers and fruit. The head of flowers with surrounding, petal-like bracts resembles a huge flower and is commonly so called. The flower is larger than that of the eastern Flowering Dogwood (Cornus florida L.), usually having 6 bracts instead of 4.

This species appreciates summer humidity. Well-established trees suffer from extra summer watering. The tree is easy prey to a fungus disease if it has been wounded, so a buffer against lawnmower damage should be provided.

If you would like a taller tree, change your search to include the 36-72 feet category.