Common name: Hardy Rubber Tree
Region of origin: Eucommia ulmoides is native to China, but is possibly now extinct in the wild(1).
Cold Hardiness Zone: 4 to 7 (1)
Mature height: 40 to 60 feet (1)
Mature width: 30 to 50 feet (1)
Growth rate: slow (2)
Crown form: round (2)
Life span: No provable information but there is said to be specimens over 100 years
Wood: Eucommia ulmoides is a diffuse-porous wood with distinct growth ring boundaries (3)
Site characteristics: Easily grown in average, medium, well-drained soils in full sun to light shade. Best in full sun. Tolerates wide range of soil conditions except wet ones (1).
Reproductive details: Hardy Rubber Tree is dioecious with male and female flowers on separate plants (4). The flowers are inconspicuous and ornamentally unimportant, stamiate--clusters of brown stamens; female-consisting of a single pistil (4).
Fruit: Capsule-like with compressed wings, 1 1/2" long, 1-seeded (4)
Propagation: Seeds require 2 to 3 months cold moist stratification and cuttings should be taken just as new growth is forming (4).
Uses: Specimen, shade, street and yard tree (2). The Chinese have used the hardy rubber tree for more than 2,000 years for its medicinal value (2). Hardy rubber tree may be the only tree which grows in cold climates from which a rubber product can be obtained (2). Typically grown as an ornamental shade tree because of its attractive glossy green foliage.
Maintenance: This is a very low maintenance tree (5).Best in full sun, pH soil tolerant, Drought tolerant (5).
Branches can be prone to storm damage (5).
Limitations: No major disease or pest problems (1)
Do not plant it in poorly-drained soil (2).
Figure 2: Geographical location of the ten populations of Eucommia ulmoides.
Figure 3: The bark of the
Hardy Rubber Tree peeled
back exposing the sapwood
Figure 4: E. ulmoides in a transverse section
Figure 5: Seeds and foliage on Eucommia ulmoides
Figure 6: Eucommia ulmoides during winter as a specimen tree
Figure 7: Eucommia ulmoides during summer as a specimen tree