by Christine Parks
At Camellia Forest, we have been collecting, growing and selling tea plants for over 35 years. Many tea varieties used in industry are proprietary, representing a substantial investment of efforts at breeding for cultivation. By contrast, our mission has been simply to make tea available to meet a broad range of interests; from curious tea lovers or avid gardeners, to a South American grower starting a new tea plantation. We offer many varieties for people to test, still only representing a small fraction of the diversity worldwide.
Indeed, Camellia sinensis originated in southeastern China, one of many types of Camellias cultivated over the centuries for form and function. Naturally growing in subtropical to temperate regions, Camellias are generally found as an understory bush or small tree. However, Camellia sinensis is grown for tea around the world under a wide variety of conditions. Two main varieties are cultivated – Camellia Sinensis var. sinensis and var. assamica – the former is typically in more temperate regions and the latter better adapted to the tropics.
High elevation subtropical mountains in places like Taiwan, Southern China, or India are thought to provide the optimal conditions for tea production. The best climate for tea production in the U.S. is going to the “Camellia Belt” of the Southeast and southern states, where there are no comparable mountains at such low latitude. But many opportunities exist to diversify and extend our efforts northward, where cooler temperatures can yield high quality and delicious teas. We already know of tea being successfully grown in the Pacific Northwest and Virginia, for example.
Finding tea varieties that grow reliably in regions in cooler and more northern regions of the U.S. will require a good deal of trial and error. A good place to start is with those varieties previously selected to grow in colder climates, such as the small leaf var sinensis from more northern regions in China, Japan or Korea. Sochi tea is another hardy variety selected to grow along the Black Sea in one of most northern tea plantations in the world, established in 1905. All are flourishing here in our garden in the central piedmont of North Carolina.
One of our small leaf tea varieties has been rated to zone 6b. It comes from seedlings planted in the UNC Coker Arboretum from the 1910’s to 1930’s from plants that may have originated in Japan. We know this variety is cold hardy based on a natural experiment in 1985, when they survived a sudden deep freeze in North Carolina. With the coldest temperatures down to -9 degrees Fahrenheit, most (but not all) Camellias in our collection were killed down to the ground. This was one of the survivors.
That said, before investing in acres of tea production, trials are needed, including several different varieties, clones and seedlings. Testing requires well-established plants (i.e., growing well on site for at least a few years); only then can they truly be tested for cold hardiness. We are working to crossbreed our cold hardy varieties with other favorites in our tea garden, but it will take many years of growth and observation to identify which of these crosses might survive similar temperatures.
While trials are still needed to determine the optimal plants for different areas in North America, it may be wise to resist the temptation to simply seek only the best cultivars for tea production. Given the realities of climate change, we need to consider the value of diversity as we adapt and trial new varieties for cooler or more northern regions. It may be that the average temperatures will rise, but at the same time, greater short-term variability could be a challenge to determining what features are best suited for long-term tea production in any one particular region. One of our priorities at Camellia Forest is to collect and preserve diverse tea varieties, to provide choices for trials, and preserve these resources for future generations.
The question of where tea will grow productively is not only a matter of temperature, of course, since the timing of first flush and growing season will depend on both climate and day length. Even if the plants survive for several years, one must consider the matter of spring frost. Plants are more tender and susceptible when they first put out their new growth in the spring. Not only can one cold night ruin the first harvest, it can kill the plant entirely!
In our gardens here in the Piedmont region of North Carolina, we have been growing several “tender” tea varieties for years (and in some cases, decades), with plantings in sheltered locations under a light pine forest or along a tree-lined field. Clearly, this is not the typical model of a tea plantation, with acres of tea planted in mostly full sun. But smaller farms might use hoop houses or frost blankets, or, as in Japan, large fans can be placed in the fields to circulate air on cold nights to protect the new growth from late frosts.
In sum, many factors will contribute to successful tea cultivation – not only the genetic background and photoperiodic requirements of the plant, but also the temperature averages and extremes, soil qualities (such as pH, nitrogen content, and drainage). We can push the northern boundaries of where tea is grown in the U.S. by choosing the right plants and by using old and new technologies, along with knowledge of local topography and micro climates. Given the time required for proper trials, a certain degree of patience and persistence is also a clear requisite.
Ours is only one experience and set of opinions, in the long history of tea selection, carried out over centuries. We welcome your thoughts, questions, suggestions for helping to support the growing “local” U.S. tea movement of the early 21st century!