To deepen the root system

Rice straw has been used for new tea planting to promote growth and reduce cold drought damage, but in recent years there has been a shortage of rice straw materials, and a coating material that has the same or better growth promotion effect as rice straw. As a result, the use of poly mulch materials is increasing.
It is said that mulching to the origin of tea plants in the young tree stage has a high growth promoting effect and can be expected to grow early.
However, if the poly mulch used with the expectation of growth promoting effect is left as it is, the root system tends to become shallow.
This is the second year since planting because it makes it more susceptible to drought damage in winter.
As it started to rain regularly, I removed the poly mulch.