Willow Oak - A Fine Street / Landscape Tree

Willow oak (Q. phellos)

Willow Oak (Quercus phellos) is medium to large, deciduous tree, part of the "red oak" group (USDA hardiness zones 5-9). It is distinguished for willow-like oak foliage. Growth rate following a 2 year establishment period is moderate (12-16 inches annually).

Willow oak grows 50-75 feet tall and 30-35 feet wide with a rounded top or canopy. Young trees tend to be pyramidal in form. Individual specimens may reach 90 or more feet under ideal site conditions. Its small ¼ – ½ inch nearly round acorns form almost every year, are not a major maintenance headache, and serve as an important food resource for wildlife.

Long stringy yellow-green long catkin flowers appear in April, a few days before leaves emerge. Unlobed 5-inch long leaves mimic those of willow trees (Salix spp.). Leaves are tipped with a single 1-inch wide bristle. Green summer leaf color turns an undistinguished yellow-brown or dull gold very late in autumn. A young tree has a smooth grayish bark which darkens and becomes furrowed with age.

Native to the Southeastern U.S., willow oak prefers a moist bottomland, organic-rich, well-drained soil. This landscape tree tolerates light shade, but performs best in full sun. Willow oak can handle a wide range of soils including clay. Once established, it copes with summer drought well. Foliage is tolerant of urban air pollution.

narrow leaves of Willow Oak

Willow oak demonstrates good disease and pest resistance and is a long-lived and low-maintenance tree. In a landscape willow oak fits into large sites, such as in public parks or along wide roadways and avenues with good soil mass for adequate moisture. The narrow leathery leaves abscise very late in the fall and make a great loose mulch scattered under other landscape plants.

Kingpin® - new selection of willow oak introduced by Bold Spring Nursery. It offers uniformity in street tree plantings along with these improved traits: darker leaf color, strong central leader (trunk). Kingpin is large 60 x 45 feet shade tree.

Katsura Tree

'Pendula' Katsura tree

Hooray! In American gardens Katsura tree (Cercidiphyllum  japonicum) is finally becoming more planted as a fine landscape tree. There are a number of great varieties to choose. This medium to large growing tree (height depending on cultivar) commands four-seasons appeal. Rated as a medium-sized 40-60 foot pyramidal, this long-lived majestic specimen may top off at 75 feet in height before its first 100 years. 

Its beautiful heart-shaped soft green summer foliage transforms to purple and gold shades in autumn. After the leaves fall they reveal its lovely symmetrical branching and scaly/shaggy bark. Often, the fall air holds a cinnamon scent reminiscent of cotton candy or a sugar-cookie.

Katsura tree is indigenous to Japan and China where it can grow an incredible 100 feet tall (USDA hardiness zones 4-8). The species is dioecious, e.g. separate male and female trees. The tiny flowers are mostly inconspicuous and small pods with numerous winged seeds are dispersed by female trees in late fall. Katsura tree is also not invasive.

Select Cultivars: some 20 varieties are listed, but I mention only 4 here:

'Pendulum' – lovely weeping form 15 to 25 feet tall and 20 to 25 feet wide. Other weeping forms also lumped as 'Pendula'.

‘Morioka Weeping’ - another weeping form, 20 feet tall and 15 feet wide, with more upright growing branches when young and  large leaves.  

‘Red Fox’ (‘Rotfuchs’) – 30-foot pyramidal tree; new spring reddish purple foliage, turns dark bronze-green in summer and orange-bronze fall color.

‘Claim Jumper’ - a relatively new gold-leaved variety that grows 25-30 feet (8-10 m) and 20 feet wide. Leaves emerge with a pink blush and unfurl to soft golden-yellow. Gold leaf color fades away by late summer.

Katsura tree is easily grown in a moist well-drained soil and in full sun to part-shade. Growth rate is equal to a sugar or red maples. Newly planted 1-2 year old trees are particularly prone to leaf scorch. During its first year or two after planting, katsura is susceptible to long dry spells and will need irrigation in periods of no significant rainfall.

Katsura are rarely troubled by serious pests or disease problems. Katsura tree and cultivars are sold at full-service garden centers, but smart gardeners are likely to quickly buy up the inventory. Rare or new cultivars, like some that are listed here, are sold by on-line specialty nurseries.

A Grand Tree Aristocrat - Southern Magnolia

Southern magnolia (Magnolia grandiflora) is native to the Southern U.S. (USDA hardiness zone 6-9). The species grows upward of 60 - 80 feet tall with a pyramidal habit when young and developing a rounded canopy at maturity. These evergreen magnolias are cherished for their attractive glossy dark green foliage and showy fragrant flowers. Large 5 to 6 inch pure white goblet shaped flowers appear sporadically from mid-spring thru late-summer. Ornate cone-like seed pods form after flowers have shed their creamy white tepals (petals). 

Young trees may not bloom for 3-5 years after planting. Its shallow roots may eventually lift sidewalk pavement as the tree ages. Southern magnolias grow 30 to 50 feet high, and some varieties need lots of room. This tree is happily suited to large commercial and residential properties, golf courses and public parks.

Four large cultivars are ideally suited for planting on wide boulevards, medians, parkways, urban parks, industrial sites and golf courses. Undersides of leaves are either green or rusty brown as noted.

• ‘Bracken’s Brown Beauty’ (50 feet x 25 feet) - rusty brown back leaf
• ‘Edith Bogue’ (40- 50 feet x 25 feet) – green back
• ‘Claudia Wannamaker’ (50 feet x 30 feet) – green back
• ‘DD Blanchard’ (50 feet x 30 feet) – brown back

Smaller growing cultivars are also available at garden centers:

• ‘Little Gem’ and ‘Hasse™  (35-40 feet in height)
• Teddy Bear® and ‘Kay Parris’ (25-30 feet in height)

Little Gem grows very shrub-like and may encompass 20 or more feet of ground area. Hasse exhibits a tree-like habit and branching is primarily upright. Teddy Bear and Kay Parris grow slowly and are better choices for small landscapes.

Leaves and flowers are proportionally smaller that the species. The glossy foliage is thick and leathery, and dark green over both the upper and lower surfaces. Kay Parris foliage is reddish brown on the underside.

Trees shed older leaves in spring as new ones emerge. Occasionally, its evergreen boughs are weighted down and snap off under heavy snow and ice loads.

Northern Catalpa

Northern catalpa or Indian cigar tree (Catalpa speciosa) has enormous presence in any landscape setting. Finding a 70 - 80 foot tree with a massive trunk and thick sinuous limbs is not uncommon from Ohio south thru Tennessee. In summer its huge heart –shaped, pale green leaves may be easily reach 8 - 12 inches long and wide. Birds often seek shelter under the foliage canopy.

Catalpa offers a spectacular flower display lasting two weeks or more in May. The tree is common along roadsides, particularly in bottomlands, often growing in poor soil. Numerous two- inch long white flowers are borne on large terminal spikes, many unfortunately hidden beneath the enormous catalpa leaves. Each flower has small gold spots within its frilly edged corolla. Narrow cylindrical cigar fruits, 8 - 15 inches in length are easily visible in the fall and winter months.

Catalpa trees are often visited by the catalpa sphinx moth whose larvae (caterpillars) are prized by fishermen for bait. Hummingbirds are a major pollinator, attracted to the floral nectar.

This fast growing tree finds only limited value in a residential neighborhood due to its coarse leaf texture. The brittleness of small limbs demands almost constant clean-up.