Cladrastris kentukea; 2” at the farm.

Cladrastis kentukea (American yellowwood) is possibly the most unique ‘native’ tree of eastern North America.  ‘Native’ because its current range is primarily restricted to scattered outcroppings in the Ozarks and southern Appalachian highlands where it often grows on shady slopes in chalky, limestone-rich soils. Yet the versatility of this woodland specimen to other soil, light and climatic conditions as well as intriguing fossil clues hint at a much broader range before the last ice age covered much of the northeastern United States; a distribution from the Ozarks east to the Atlantic and north to the southern Great Lakes and the Hudson River Valley.  Cladrastis itself is a very small genus; consisting of one species in North America and an additional eight in east Asia.  It is closely related to another genus in the Fabaceae (pea/legume family), Styphnolobium, the pagodatree with which—unlike most legumes—it lacks the root/microbial symbiosis to fix nitrogen in the soil.

Whatever its past—or present—the yellowwood is an outstanding choice for smaller gardens.

Cladrastis kentukea; bark detail

As a landscape plant, Cladrastis kentukea typically matures at 35-50 feet in height with a broad, rounded crown of upright branches.  The smooth, grey bark mimics that of Fagus grandifolia (American beech), only slightly darker in tone.  The pinnate leaves, which resemble Juglans regia (English walnut) are 8-12” long with 7-11 leaflets and emerge a bright yellow-green maturing to dark green before turning a bright clear yellow in autumn. Once the tree reaches a decade or so in age, late spring also brings a mass of intensely fragrant white flowers in pendulous 8-14” racemes. Resembling Wisteria, the flowers are typically more numerous every second or third year.  The flowers are followed by decorative 2-4” brown pods that persist late into the winter.  Cladrastis tolerates a wide variety of soils, but prefers sun or very light shade and ample moisture when young; as it matures, water becomes less of an issue.  The tree is deep-rooted, making it suitable for planting near sidewalks and patios; the deep roots also allow shrubs or perennials to grow under the canopy.  Pruning should be conducted in late winter, before the sap begins to rise as yellowwood tends to ‘bleed’ profusely, like many maple species.

Cladrastis kentukea; flower detail

The common name yellowwood refers to the bright yellow heartwood of the tree; this heartwood yielded an intense yellow dye used by both native Americans and early Appalachian settlers.  Native Americans also used the wood for building and figurative carving, while early settlers prized it for gunstocks. Today, the wood is used for decorative items and woodturning.  The flowers yield abundant nectar and are a favorite of honeybees.

Cladrastis kentukea; autumn color beginning

Cladrastis kentukea is relatively pest-free; with only scattered instances of borers or Verticillium wilt.  Its main weakness is its somewhat brittle wood (hence the genus name: from Greek kládos/κλάδος ‘branch’ and thraústos/θραύστως ‘snap’ or ‘brittle’), so siting in a somewhat sheltered location is preferred.  The tree can also be damaged by heavy ice storms.  It also has a tendency to be low-branched, a problem easily corrected in youth by White House Natives’ rigorous pruning program.  We supply Cladrastis kentukea in a range of sizes including 2”, 2½” and 3” caliper.  We strongly encourage you to make Cladrastis a regular feature of the urban gardens you design and plant.  You will not be disappointed!

Quercus coccinea, 3″

Quercus coccinea (scarlet oak) is another staple of the woodlands of eastern North America.  Often confused with red oak (Q. rubra), black oak (Q. velutina) and especially the closely-related pin oak (Q. palustris), it can be distinguished by its bristle-tipped seven-lobed leaves with broad ‘C’-shaped sinuses, compared to the deeper, ‘U’-shaped sinuses of Q. palustris.  Like the southern red oak (Q. falcata), which we recently featured, it has become more popular in the landscape trade in recent years due to its tolerance of urban conditions.

Quercus coccinea coloring up in mid-autumn.

Growing as tall as 150 feet in its native range—which spans from southern Maine west to Wisconsin and south through Missouri to northern Louisiana, Alabama and Georgia—scarlet oak typically matures at 60-75 feet tall in the landscape with an irregular, rounded crown.  Unlike some of its oak brethren, scarlet oak tends to cast a broken rather than dense shade.  The shiny, dark-green leaves are 5” to 7” long and around 4” wide and color late in the autumn, with a reliable scarlet color that slowly fades to claret then brown as winter progresses.  Acorns are usually around ¾” long, half-covered in a scaly, bowl-like cup; light in most years but with a heavy crop every third or fourth year.  The thin, brownish-grey bark develops broad, widely-spaced ridges with age.

In the wild, scarlet oak is a climax forest species, preferring upland sites with good drainage and often thriving on poorer, rocky, gravelly or sandy slopes.  In the landscape, it is adaptable to a wide variety of conditions, disliking only alkaline soils.  Once established, it exhibits good drought tolerance and is far less prone to chlorosis (leaf yellowing) than its sister species pin oak.  It typically grows quickly when young and usually begins to bear acorns when less than twenty years old.  Scarlet oak makes an ideal shade tree for larger spaces due to its dappled shade which allows a variety of shade-loving shrubs to thrive under its canopy while still receiving filtered sunlight.

Quercus coccinea; fall color detail

Wood from the scarlet oak is often sold as ‘red oak’ in lumber yards.  While not as dense and durable as white oak (Q. alba), the reddish tone and coarse grain of the seasoned wood is valued for cabinetry, furniture and interior detail work.  Like many oaks, dried acorns were leached in water then ground for flour by Native Americans; the acorns are also an important food source for many large native songbirds, grouse, turkey and of course, white-tailed deer and squirrels.

Quercus coccinea in midwinter.

White House Natives supplies Quercus coccinea in a range of sizes including 2”, 2½” and 3” caliper.  As with all our trees, we prune regularly and rigorously, so the trees you receive are ready to make an instant impact on your next project.