Trees and Shrubs

The following posts cover topics related to deciduous, evergreen, coniferous, hardwood and softwood trees and shrubs.

• 2000-Year-Old Date Palm Seed Sprouts into Sapling

• American Red Raspberry

• Balsam Fir

• Common Persimmon

• Dealing with Hazardous Defects in Trees

• Evergreen Huckleberry

• Flowering Dogwood

• Golden Currant

• Highbush Blueberry

• Scientists Discover City Tree Grows Twice as Large as Country Clone

• Sugar Maple

• Two New Lilacs Debut at the U.S. National Arboretum

• Western Redwoods Endangered by Killer Microbe

• The Wollemi Pine: Rare Conifer Dates Back to Jurassic Age

Golden Currant

Ribes aureum


Alternate common names

Buffalo currant, fragrant golden currant, golden flowering currant, clove currant, spicebush

Description

General: Currant family (Grossulariaceae). A native shrub 1-3 m tall, spineless, with numerous, erect-arching branches forming an irregular crown up to 6 meters tall or more; bark gray to red-brown; rhizomatous. Leaves deciduous, light green and glossy, alternate or clustered, orbicular or cuneate-ovate with 3-5 rounded lobes, (0.6-)1-2.5(4.7) cm long and wide, cuneate to subcordate at base, glabrous or sometimes lightly hairy beneath. Flowers in short racemes of 5-10(-15), with the fragrance of cloves; long-tubed (from fused sepals) and trumpet-shaped, with 5 yellow sepal lobes spreading at the top, with 5, short, reddish petals inserted at the top of the tube. Fruit a berry 6-10 mm diameter, globose to ellipsoid, ripening from green to yellow to red and finally black to dark purple, with numerous seeds. The common name pertains to the conspicuous, golden flowers; “currant” is the general name for Ribes fruit.

Variation within the species: Ribes odoratum, often considered a distinct species, recognized by its considerably larger flowers, has been placed (re-placed, as var. villosum) as the eastern segment of the broader species.

Var. aureum – (golden currant)

Var. gracillimum (Coville & Britt.) Jepson – (golden currant)

Var. villosum DC. – (fragrant golden currant, buffalo currant, clove currant). Synonym: Ribes odoratum H. Wendl.

Distribution: Var. aureum is widespread in the western US and southeastern Canada, with populations in Ontario and perhaps Quebec, as far south in the US as trans-Pecos Texas. Var. gracillimum is endemic to California. Var. villosum in the central US, from western Texas to Montana and eastward to New York and Vermont; it is absent from the Atlantic seaboard. The species is naturalized in Europe from garden escapes.

Uses

Wildlife: Fruits of Ribes species, including the golden currant, are a valuable food source for songbirds, chipmunks, ground squirrels, as well as numerous wildlife species and other animals.

Ethnobotanic: The sweet and flavorful fruits are full of seeds but are popular for making jam, jelly, pie, and even ice cream. Some western Indian tribes used currants (Ribes species) for making pemmican. The Kiowa Indians believed that snakes were afraid of the currant bush and used it as a snakebite remedy. Other tribes have used the fruits to color clay pots.

Conservation: The fragrant (clove odor), golden-yellow flowers of spring, yellowish to red fall foliage, edible fruits, and wide ecological range make golden currant a valued ornamental shrub for a variety of natural landscapes. Golden currant is easily cultivated from seed or cuttings.

Adaptation

Golden currant grows in grasslands, coniferous forests and woodlands, and riparian and mountain shrub communities. It occurs on floodplains, along streams, in ravines and washes, by springs, and on mountain slopes, at elevations of about 800–2600 meters. It is generally an early to mid-seral species in western coniferous forests. Var. villosum occurs on cliffs, rocky slopes, ravines, bluffs, open hillside, and thicket margins, often in sandy habitats. Golden currant is somewhat shade tolerant and may grow in open, scattered, and dense pine stands, but it is usually suppressed by a denser canopy.

Flowering (March–)April–June, just after appearance of the leaves; fruiting (May–)June–August.

Establishment

Plants of Ribes generally begin fruiting after 3 years. Seeds may remain viable in the soil and duff for many years. Germination is enhanced by scarification, but relatively good germination of golden currant seeds was obtained by stratification at -2.2–2.2 degrees C for 60 days without scarification.

Golden currant transplants well and forms suckers. Plants can also be grown from cuttings. It reproduces vegetatively by rhizomes, sprouting after cutting and fire.

Management

Golden currant can be used to re-vegetate roadsides and disturbed areas, such as mine spoils and rangeland. It is rated mostly good in initial establishment, growth rate. persistence, germination, seed production, ease of planting, and natural spread. It tolerates shearing and may be used on dry, exposed sites in a range of soil types, and it is a good soil stabilizer.

Golden currant is an alternate host for white pine blister rust (Cronartium ribicola); this and other species of Ribes have been targets of various eradication efforts where white pine is of commercial interest.

Fire top-kills golden currant, but it can survive low- to moderate-severity fire by sprouting from rhizomes. Such fires also scarify soil-stored seed and enhance germination. Severe fire probably kills golden currant and may destroy soil-stored seeds.

Cultivars, Improved and Selected Materials (and area of origin)

Golden currants are readily available from commercial sources. One cultivar (‘Crandall’) has been referred to as "the North Country's answer to Forsythia." Other horticultural selections have been made for hardiness, flower color and density, and fruit taste and size.

Related topic: Growing currants from cuttings

Source:
USDA, NRCS, National Plant Data Center & the Biota of North America Program

Growing currants from cuttings

I recently had the good fortune to be given a few cuttings from a Golden Currant (Ribes aureum), a handsome berry bush native here in California. Since I'd really like to establish one or two of these shrubs in my backyard, and hopefully enjoy a bountiful currant harvest in the not-too-distant future, I've been carefully trying to get the cuttings to take root.

To figure out the best way to root my cuttings, I consulted the California gardener's bible, Sunset's Western Garden Book. The first step was to obtain some rooting hormone, which you should be able to find at any good nursery. After lightly wetting the stem of each cutting, I dunked it in the powdered hormone until it was thoroughly coated. I then dug a two inch deep hole in a container of damp potting soil I had on hand for the purpose. I inserted the first cutting in the hole, gently pressed the soil in around it, and then did the same for my other cuttings, spacing them a few inches apart in the container.

After lightly watering the cuttings in their new soil bed, I covered the pot with a plastic bag that I secured around the top with a rubber band. According to the garden book, this will help maintain humidity and keep the cuttings moist. Following Sunset's instructions, I've also been removing the bag for a short period each day to give the cuttings some air, and have also been setting them out in the sun in the backyard, on the principle that plants like sun. (A shocking idea, I know.)

It's been a little over two weeks and my cuttings are just beginning to show signs of new leaves emerging. Apparently the emergence of leaves coincides with the growth of roots, so once a few full-fledged leaves have appeared I should have baby currant plants for the garden. I expect it'll be at least another couple weeks before I know for sure if they've put down roots...as you've probably guessed by now, this whole rooting process takes quite a bit of patience. So until I have thriving golden currant plants in my backyard, I'll just have to make do with admiring a photo:

Golden Currant
Ribes aureum

Photo courtesy of the US Department of Agriculture

Related topic: Golden Currant Fact Sheet

Evergreen Huckleberry

Vaccinium ovatum


Alternate Names

California huckleberry, shot huckleberry, huckleberry, winter huckleberry, evergreen huckleberry

Uses

Ethnobotanic: Tribes in British Columbia and western Washington use the berries of evergreen huckleberry. These tribes include the Sechelt, Comox, Straits, Halkomelem, Lower Nlaka'pamux Salish, Nuu-chah-nulth (Vancouver Island's West Coast), and the Quinault of Washington. Evergreen huckleberries were well liked and people often traveled great distances to obtain them. The berries ripen late in the year, around October or November. They are the last fruits to be gathered in the season round and are said to be even tastier after freezing. The berries are eaten fresh, usually with oil. The berries are also sun or smoke dried, partly mashed, pressed into cake form, and wrapped in leaves or bark. Today they are made into jam or used in cooking.

The leaves and berries are high in vitamin C. The leaves and finely chopped stems contain quinic acid, a former therapeutic for gout said to inhibit uric acid formation but never widely used because of mixed clinical results. The leaves have been widely used to lower or modify blood sugar levels. Many herbalists maintain that huckleberry leaf tea may be useful in stabilizing blood sugar levels in cases of diabetes, and medical research has shown that consumption of the leaf extract decreases blood sugar levels shortly after administration. Taken on regular basis, huckleberry tea will gradually help alleviate both glycosuria and hyperglycemia and appears to have a beginning, but useful effect as an adjunct treatment to diabetes mellitus. The leaves are believed also to stimulate appetite, and have astringent and antiseptic qualities that are useful in urinary disorders.

Horticulture: Evergreen huckleberry is an excellent horticultural choice due to its beautiful, glossy, evergreen foliage and tolerance of a wide range of light levels. The foliage is often used in flower arrangements.

Wildlife & Livestock: The foliage of evergreen huckleberry is browsed by elk and deer. Flowers attract butterflies. For several species of grouse, huckleberries are among the most important summer and early fall foods. Berries are eaten by chipmunks, black bear, mice, scarlet tanagers, bluebirds, thrushes, and other songbirds. Deer and rabbit browse freely on the plants. Because of their food value to wildlife and their dense shrubby growth, evergreen huckleberry is worthy of inclusion in hedgerows.

In some localities goats and deer crop evergreen huckleberry rather closely, utilizing 30 to 40% of the leafage and current twigs. Sheep crop it somewhat less closely but it enters into their diet to a considerable extent in late summer and autumn. The browse rating is fair to poor for sheep, goats, and deer; poor to useless to cattle; and useless for horses.

Description

General: Heath Family (Ericaceae). This erect, evergreen shrub is stout, from 0.5-3 m tall. The glossy green leaf blades are 2-5 cm, ovate, leathery, serrate, with glandular hairs on the lower surface. The umbel-like inflorescence emerges from the leaf axils. Urn-shaped flowers are bright pink. The berries are 6-9 mm, purplish-black. Evergreen huckleberry does not generally root easily.

Distribution

Evergreen huckleberry grows from the west side of the Cascades in Washington to the coast of British Columbia, to the redwood area of California. It is sporadic south to Santa Barbara, California and in the coast ranges to the central Sierra Nevada Mountains.

Establishment

Adaptation: Vaccinium ovatum grows in edges and clearings of coniferous woods, at elevations from 3-800 m. Evergreen huckleberry can also be found near beaches in the salt spray zone. This huckleberry grows in moist to slightly dry soils. It will grow in full sun to full shade, although the plants prefer some shade.

Propagation: Evergreen huckleberry can be difficult to propagate or transplant, but it is available in some nurseries. It can be grown from cuttings, from seed, or by layering. Huckleberry cuttings should be taken while the plant is dormant, from November to April. Their rooting success is fairly sporadic.

Evergreen huckleberry requires excessive drainage and acidic soils to become established. It does best in full or partial shade; it may tolerate morning and winter sun.

Live Plant Collections: Evergreen huckleberry is propagated by cuttings from fully matured shoots taken in fall and winter, when the plant is dormant. Cuttings made from the previous year's growth taken the third week in April rooted 100% (Vancouver, B.C.). Application of 0.3 to 0.4% IBA talc to the freshly cut stem surface and basal heat (21°C; 70° F) to potted plants will enhance rooting.

Young plants can be salvaged, but they should be transplanted when they are less than one foot tall. Frequently, these small plants will turn out to be new shoots of a mature plant reviving from deer browsing or logging, and will die from lack of roots.

Seed Collections: Berries should be collected when they are ripe (from August to September or later). The blue-black fruit is easily collected by hand picking or by beating the bush over a large bucket. Following collection, chill the fruit at 10°C for several days. Clean seeds by macerating and floating off the pulp and unsound seed. Clean seeds carefully; they are minuscule, so you may want to use pantyhose or cheesecloth to strain the seed from the pulp.

Seeds dried at 15-21°C for two days can be stored in a refrigerator for up to 12 years. Fresh seeds not planted in the fall may germinate better if cold stratified for 1-3 months. Stored seeds germinates well when exposed to alternating temperature and light regimes of 28°C light for 14 hours a day and 13°C dark for 10 hours.

Fresh or stored and cold-stratified seeds can be sown directly into flats or small pots (a salt shaker can be used for sowing). Plant in a mixture of sand and peat moss. Seedlings will begin to emerge in a month and will continue to emerge for a long period thereafter. Transplant seedlings into larger pots 6 to 7 weeks after emergence. Plant outside after the first growing season. Seedlings are slow growing, and it may take 2-3 years for a nursery-sized plant to develop.

Management

This plant grows very rapidly in moist, shady conditions. If summer drought occurs, the plants should be watered so roots are kept fairly moist.

Traditional Resource Management: This includes the following: 1) occasional burning to stimulate new growth; 2) pruning the branches after picking the berries to stimulate new growth and fruit production the next growing season; and 3) ownership of red huckleberry shrubs provides the basis for careful tending and sustainable yield of valued resources.

Cultivars, Improved and Selected Materials (and area of origin)

This species is readily available from native plant nurseries within its range.

Source:
USDA, NRCS, National Plant Data Center & Oregon Plant Materials Center

Highbush Blueberry

Vaccinium corymbosum


Alternate Names (for several highbush species)

Northern highbush blueberry, southeastern highbush blueberry, Maryland highbush blueberry, black highbush blueberry, American blueberry, New Jersey blueberry, rabbiteye blueberry, swamp blueberry, tall huckleberry, mayberry, whortleberry

Uses

Fruit production: V. corymbosum, highbush blueberry, a native North American shrub cultivated throughout the country, is the major blueberry-producing species in commerce. More than 50 cultivars have been developed, primarily for commercially valuable fruit characteristics and seasonality.

Landscaping: A few selections are used in landscaping, especially as plantings in wet areas or to attract wildlife.

Food: Highbush blueberries are eaten raw, smoke­dried, sun-dried, boiled, and baked in a wide variety of culinary settings. They have one of the highest concentrations of iron of the temperate fruits.

Wildlife: Blueberries provide important summer and early fall food for numerous species of game birds, songbirds, and mammals.

Description

Highbush blueberry is a native, upright, 6-12 feet tall, crown-forming shrub. The common name refers to the relatively tall stature of these plants. Twigs are yellow-green (reddish in winter) and covered with small wart-like dots. Leaves are deciduous, alternate, simple, elliptic or ovate, 1 to 3½ inches long and slightly waxy above with pubescence (hairs) at least on the veins beneath. The white or pink-tinged flowers are small and urn-shaped with 5 petals, and occur 8 to 10 per cluster. Flowering occurs February to June, sporadically in the southern portion of its range; fruiting occurs April to October, about 62 days after flowering. Fruits are ¼ - ½” blue-black berries with many seeds.

Adaptation and Distribution

Widespread in eastern North America, the highbush blueberry has been introduced outside of its natural range for commercial berry production. The most common native habitat is in moist or wet peat of moderate to high acidity – in and around marshes, swamps, lakes and flood-prone areas. V. corymbosum also occurs in drier areas such as dunes and barrier beaches, rocky hillsides, oak woods, and pinewoods.

Establishment

Highbush blueberry produces abundant fruit every year. Highbush blueberry (V. corymbosum) is self-fertile, but cross-pollination increases fruit set and results in larger, earlier berries with more seeds (Agriculture Western Australia 2000). Other species of the complex are partially or completely self-incompatible. Bees are the primary pollinators. The seeds may be widely dispersed by birds and mammals, but germination can be reduced up to 15% after passing through an animal gut. In the southern portion of its range, highbush blueberry seeds have thick seed coats and require cold stratification before germination. Those from northern regions produce thinner seed coats and germinate in the autumn after dispersal.

Plants of highbush blueberry can be propagated by seeds or cuttings.

Occasionally sprouting has occurred from root-crowns after top kill by fire or disturbance. Plants have also been noted to produce root sprouts that emerge 1-2 meters away from the parent plant.

Management

Ideal soil for cultivation is moist, high in organic matter, highly acidic (4.5-5.5), and well-drained. The plants grow in full sun to partial shade, but those in open sites produce more flowers and have brighter fall foliage color.

Pests and Potential Problems

Insects, diseases and wildlife pests need to be controlled in commercial production.

Cultivars, Improved, and Selected Materials (and area of origin)

Improved varieties for commercial berry production are readily available. Non-selected materials for conservation use are also available from nurseries.

Source:
USDA, NRCS, National Plant Data Center & the Biota of North America Program