Within Tian Di Ren is the universe. Let's look at the definition of Tian Di. It means Heaven and Earth / World / Universe; doesn't that cover almost everything? Almost. In this case, it doesn’t cover people. When mentioning all that influences finished tea that is ready to brew, we have to look to the people (Ren) as well as to Heaven and Earth / World / Universe (Tian Di).
So if we look at just Tian Di's influence on tea, how does Tian Di make great tea? A pampered leaf will not make the best tea. One of my favorite tea master quotes is: “Give me three cups of tea that are like sweet nectar and I, the drinker, will grow bored and become sick of it. Tea has to be bitter and astringent as well.” But it's a question of how much bitterness and how much astringency and at what point after the tea is tasted and for how long?
Plant stress created by Tian Di is beneficial as long as it slows leaf growth, but not so much that no leaves grow. The plant that has to struggle to put forth leaves has a special character. This is much like a tree that grows just below the tree line is often gnarled, strong, and visually striking when compared to those that grow in the supportive environment of the Willamette Valley. It’s almost as if the plant has to look within in order to be able to grow. When we look at the tree, we see the outward expression of its inner experience; as we taste the tea, we experience its bitterness, its sweetness, and its character. The tea strikes a deep chord within, resonating as we connect to nature and to the universe over the course of a few sips.
On the other hand, if the plant has an easy life, the leaves grow very easily. When looking at factors that lead to plant stress which result in slower growing tea, we see that these are factors resulting from Tian Di.