The plants go into the wilting stage in late October . Biennial seedlings of them begin to turn green during the last ten-day of Marth in spring in Harbin , annual growth follows the rhythm of slow-fast-slow .
于秋季10月中下旬进入枯萎期。二年生苗在哈尔滨地区春季3月下旬开始返青，年生长量呈慢-快-慢的变化规律。
marth