How Tea Grows: Anatomy of a Tea Plant
With the wide variety of tea styles produced worldwide, it can be hard to believe that all types of tea, excluding herbal tisanes, are made from the same species. Flavors and even the physical attributes of the finished leaves can vary drastically from tea to tea, giving the impression that green teas are in some way fundamentally different from black teas.
But in fact, all teas come from the same Camellia sinensis plant. Thousands of years of cultivation have teased myriad colors, textures, and flavors out of this single species, which now distinguish the huge variety of teas we know and love.
So how are so many distinct styles crafted from this one species? While many of the physical differences are shaped in the crafting methods used, the true depth of quality flavor can be traced back to the actual growth of each plant. Taking a close look at each part of the Camellia sinensis plant can help us understand how every tea develops its unique characteristics.
Just like all plants, Camellia sinensis grows wild through the natural distribution and pollination of seeds. However, this is rarely how plants on a tea farm begin life. Instead, most tea plants are grown from cuttings, or grafted to existing root systems, in order to preserve the exact genetic makeup of the parent plant. This part of the growth process determines the tea’s variety.
Tea plants grown from seed will necessarily vary from ancestral plants over time, letting the species adapt to new environmental conditions through the process of natural selection. However, this genetic diversity can also produce diversity of flavor, making seed-grown plants a gamble for tea farms investing in new growth.
Instead, most farmers prefer to work with established cultivars, or ‘cultivated varieties’, with tried and tested flavor profiles. By replanting cuttings when the tea plants pass their years of peak productivity, tea farms can maintain the flavor profile their customers expect while also keeping yields high.
In some traditions of tea cultivation, like those in the Phoenix Mountains of Guangdong Province, the age and lineage of a tea variety is key to the overall quality of the tea. Rather than replanting regularly, farmers of Phoenix oolong teas value old trees for the more concentrated flavor they produce. Over many generations of old grove trees, farmers in this area have developed cultivars with distinctly fruity flavor profiles, each as different from the others as a Granny Smith apple is from a Fuji.
Even two plants grown from the same ancestry can diverge after planting, though, if their roots aren’t planted in the same place. Everything from the natural chemical makeup of the soil to the surrounding plants and ambient temperature can change the way a tea plant develops over the course of its life. These effects add up to create a tea’s provenance.
Soil nutrition can be extremely important, as in the case of oolongs from the Wuyi Mountains, where the soil is rocky and rich in iron. The mineral-rich flavor of these teas has made them some of the most distinctive and famous in China, with the best coming from the rockiest cliffs. There are few better examples of the way in which a plant’s roots absorb and integrate the very land into the flavor of a finished tea.
The roots of a tea plant also play a large role in developing natural sweetness and flavor complexity in temperate climates like Fujian or high elevations like Darjeeling. When temperatures dip low enough to send the tea plant into a dormant winter season, the roots are where the plant stores glucose while it is not growing new leaves. During storage, it processes these molecules to create more complex flavor compounds.
The stem is the carrier for these natural sugars, the link between the nutrients of the soil and the photosynthesis taking place above ground. In the summer, when excess glucose is produced by mature leaves, it carries the natural sugars down to the roots, where it can be stockpiled. In the spring, they are sent to power the growth of new buds before they open to begin photosynthesis.
This process is the driving force behind the importance of harvest date. Teas picked in late summer or fall are low in natural sugars, as any excess is being carried to the roots for storage. By contrast, the first buds of spring contain the greatest quantity of complex glucose molecules, delivered by the stem before the growing leaves unfold.
The cultivation of tea stems has fundamentally changed the way tea grows around the world, as well. While most tea plants are trimmed consistently to maintain a bush-like shape and keep leaves within easy reach, plants allowed to grow without trimming will develop into small trees.
At the pinnacle of the growth process, we finally come to the tea leaf. The photosynthesis performed by growing leaves is what ultimately powers the continued growth of the plant by collecting sunlight and producing all our favorite natural compounds, like caffeine, theanine, and EGCG. They also contain bitter compounds like tannins, which are released more easily when leaves are chopped or broken during harvesting.
Tea leaves can produce other compounds that influence flavor under specific conditions, like the enzymes created to fend off attacking pests that create the unique honeyed flavor of Mi Xiang teas. Harvesters maintain plucking standards of the number of leaves and buds to be included, depending on the style of tea to be made, and select only the configuration that will produce the ideal flavor in the finished tea.
Collected leaves will be processed through a set of steps that typically includes wilting, oxidation, and drying before undergoing a finishing roast to remove the last bits of moisture. The selection and ordering of these steps is what makes up a tea’s craftsmanship. This treatment of the leaves is what transforms thousands of nearly identical varieties into the recognizable categories of tea that can be seen on shelves and in canisters, but the fundamentals of tea flavor are laid long before this process begins.
For this reason, we always recommend choosing teas based on variety, provenance, harvest date, and craftsmanship, rather than added flavors or romantic names. By learning more about the anatomy of a tea, we can understand how flavor develops from the very beginning, and better predict which teas will taste the very best.
Find the standards we use for picking out the best teas >>
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Comments on this post (1)
You’re right about tea seeds and their inherent variability; it can be a two-edged sword. On the one hand, variation among seedlings is paramount lest the tea industry becomes stuck in a genetic rut. On the other hand, variation can be costly, especially for new growers who must sort out the genetic losers from the winners. It’s more reliable, at least in the short term, to use clones with known performance.
Anyway, it’s a fascinating subject. I’ve written a bit about the prospects of starting a tea camellia garden from seeds. Please share it with your readers if you think it would be helpful.
Thanks for the article,
— Mike Loeb