The rushes which grow around Tachia and Yuauli along the lower reaches of the Ta-an River are known as Tachia rushes and are harvested three times a year. After harvesting they are tossed and laid out to dry in the sun. Broken or badly formed rushes, and any which become damp due to rain while drying are sent to be processed at a factory.
這些生長在大安溪下游大甲與苑裡一帶的藺草被稱為大甲藺，一年三收，收割後要經過草、鋪散曝曬等過程，有些長不好或曝曬時遇雨淋的草就要經過加工廠處理。