Most of the plants in the Asian Collection resulted from collecting trips to Eastern
Asia, but some of the plants originally came from nurseries specializing in Asian
plants. Many plants native to China and other East Asian countries were first
introduced to the United States in the late 1800's, but the original collections
did not represent the full range of natural genetic diversity found within a given
species. We need to collect new specimens of these plants if improved ornamental
characteristics, enhanced tolerance of heat, cold, and drought, and better resistance
to pests and diseases are to be realized. The National Arboretum is a member of
North American China Plant Exploration Consortium (NACPEC), and works with other
public gardens to bring new Asian ornamental plant germplasm back to North America for evaluation, use
in breeding programs, and to preserve plant genetic resources that are threatened
by burgeoning development and habitat loss in Asia. Arboretum staff still participate
in exploration trips to remote parts of China. With each trip to China, NACPEC
increases the genetic diversity of cultivated Asian plants.
What is the red pagoda for?
The shelter, styled after a Chinese pagoda, sits atop a knoll on the ridge that
separates China Valley and Asian Valley. Here you can rest for a while; the inclines
are steep in the Asian Collection and even though distances are short, the walk
is moderately strenuous. From the pagoda, you can enjoy a panoramic view of both
valleys, the Anacostia river, and the wooded
slopes of Hickey Hill.
How hardy are the camellias?
Quite hardy. The cold hardy camellias introduced by Dr. William Ackerman have
experienced temperatures as low as -12o F without injury and are fully hardy in
USDA hardiness Zone 6B. The hardiness of these hybrids comes from a seedling
tea-oil camellia, Camellia oleifera, that was planted in Asian Valley in
1949. It was one of the few camellias to survive the brutally cold winters of
the late 1970s and is itself a National Arboretum introduction named 'Lu Shan
Snow'. Aside from hardy National Arboretum introductions, the Camellia Collection
is home to other hardy camellias including cold hardy Camellia japonica
varieties that bloom in March and hardy fall blooming Camellia sasanqua
see that you have bamboo in your collection. How do you keep it in bounds?
Not all bamboos are invasive. Clump-forming Fargesia, for instance, really
doesn't spread much and coexists nicely with other plants. Because they are important
Asian plants, several clumps of running species of bamboo were planted in the
collection and were given enough room to grow into large groves. All bamboos are
monocarpic individual plants with similar genetic makeup, flower simultaneously,
and die after flowering; although there is no way to know for sure when it will
happen, each of the bamboos in the collection will someday flower and die. If
you need to contain the spread of bamboo, you can mow the new shoots as they emerge
in spring, dig out the spreading underground rhizomes, or build a substantial
plastic or concrete barrier that extends at least two feet below the soil surface.
Is the palm
at the top of Hickey Hill hardy, or do you dig it up and bring it indoors for
This is a needle palm, Rhapidophyllum hystrix. It is the hardiest of the
palms and can be grown in USDA hardiness Zone 8 and may even succeed in Zone 7
if given winter protection from drying winds. The specimen at the top of China
Valley was planted in 1968 before the Asian Collections were developed and is
now 15 feet in diameter. The needle palm is not Asian at all; it's native to the
Coastal Plain of the southeastern United States. It remains in the Asian Collections
because its location near the top of China Valley is consistently a few degrees
warmer in winter than any other location on the grounds. Cold air drains away
from its position on the slope of Hickey Hill, protecting it from late spring
and early autumn frosts. It doesn't have a trunk like other palms it's more like
a large shrub. The name comes from the long, sharp protective spines that radiate
from the center of the plant.
some other sources for information about Asian plants?
If you're interested in buying some Asian plants, check reference books and your
local nursery to see which can be grown successfully in your area. Check the Plant
Sources Page for more information on how to find that special Asian plant that
you've been looking for.