The camellia sinensis (tea) plant requires some specific care and conditions. As long it is the same plant and the soil condition is good, the nutrition value will not differ too greatly. Depending, however, on the flavor profiles you are going for, the environment and care will affect this.
For a tea plant/seed to really root itself into the soil, it takes about 3-5 years. If you rush it, tea can grow in the first couple years as well. However, this will not give the plant a chance to get a firm foundation.
This is what happened to a lot of tea fields in Korea a few years ago when the long, harsh winter hit – a lot of the plants were uprooted from the snow and strong winds. Those farmers that took the time to plant the seeds and wait patiently for the leaves to grow at its proper pace truly reaped what they sowed.
Tea plants generally grow in regions which have a definite winter (cold) and summer (hot). The most desirable condition would be a region that has a definite “four seasons”. If you desire leaves that produce a more rich, full flavor, the ground on which it grows needs to get cold enough (without freezing) and then, gradually in time, needs to warm up.
In Korea, most of its tea is produced mainly in the southern regions for this particular reason. The northern regions get too cold in the winter (below freezing) and the plants/roots cannot survive. Regions that don’t get cold enough or get too warm (like the Jeju Islands) may produce teas that taste a bit lighter or less rich in flavor. If you prefer lighter flavor tones, seek after teas from such warmer regions.
The region in which the fields are located also play a vital role in the final taste. The most ideal location would be either near oceans or near mountains. The reason for this is that, like most other agricultural products, the right balance of exposure to sunlight and shade is important. Too much sun will cause the leaves to either grow too quickly or dry and wither. Not enough sun will cause the leaves to not grow at its proper pace and cause lack of some of its nutritional components.
Having the tea field near an ocean allows the morning dew and fog to create a natural “barricade” for the leaves from the sun’s harsh rays. As the day progresses, this “mist” collects, allowing for the leaves to get the proper amount of exposure of sunlight. Having the tea field near a mountain, or tall hill, will allow the mountain/hill to create a natural shade for a portion of each day.
If these natural conditions cannot be met, some will also use mesh nets to create human-made shading for the leaves. Carefully attention is necessary to make sure that the leaves receive the right balance of sun and shade to produce desired flavor profiles and nutritional values.
All in all, the right combination of environment, condition and farming techniques are needed to produce the desired flavor and aroma. No matter how well you might process the leaves, if the basic foundation is not there, it would be difficult to get the results you want.