Very thanks to their work and explanation written August: * We'd rather love to pull the big leaves as weeds. "San-tou-sai" are still remained after that. Work: In our work, we easily pull the leaves enough, so, do that. "San-tou-sai" grows slow in this season, the weeds grows are not waste. The Big leaves: They have the acid and (*wither) coloured thick brown more than "Shiso". wither: 1. (of a plant) become dry and shrivelled. "the grass had withered to an unappealing brown" wither - Google Search wilted: 1. (of a plant, leaf, or flower) become limp through heat, loss of water, or disease; droop. wilted. - Google Search In addition: After we cut the leaves, "Shiso" grow well. We never saw that "Shiso" are there before that cutting them. (* 21th, Aug in 2022) *Link 1: https://www.gov.uk/government/collections/agriculture-in-the-united-kingdom *