Tea seed cake is a by-product of oil-tea camellia seeds after oil pressing, with many uses for fertilizing fields and repelling insects

Tea seed cake, also called tea seed meal or tea bran, is the residue left after oil-tea camellia seeds are pressed for oil, often pressed into dark brown cakes or crushed granules. It contains tea saponin, crude protein, and a certain amount of nitrogen, phosphorus, potassium nutrients and organic matter, and has long been a common natural material in rural areas.

In cultivation, the main use of tea seed cake is as an organic fertilizer. After composting, applying it to the soil can supplement organic matter, improve compaction, and provide relatively mild and lasting nutrients for vegetables, fruit trees and flowers. Some flower growers also use it to grow orchids, believing its fertilizing nature is gentle, but the prerequisite is that it must be fully fermented, otherwise it easily burns the roots.

The tea saponin in tea seed cake is a natural surfactant, with good repellent and inhibitory effects on mollusk pests and underground pests such as snails, slugs and white grubs, and in the past it was often scattered into rice fields and vegetable plots to prevent insects and snails. In addition, the older generation was used to washing hair, dishes and clothes with it, and its stain-removing and foaming effects are quite good; it is also used when clearing some fish ponds.

When using tea seed cake, pay attention to the method. Direct large amounts of contact with plant roots may cause fertilizer damage, so it is recommended to first crush it, add water and compost it to ferment, then dilute it for watering or mix it into the soil. Because tea saponin is quite toxic to fish and aquatic organisms, do not apply it near fish ponds and ditches, and it should not be used in excess over the long term, so as to avoid accidentally harming beneficial soil organisms such as earthworms.