PURPOSE: To facilitate the separation of the root part of a rush seedling without damaging the seedling by placing a specific pretreating part before a rush seedling separation apparatus.

CONSTITUTION: The objective apparatus is provided with a pretreating means 22 having a hook needle 21 to be thrust into the root part from under and hook and cut the root part of a rush seedling during the returning process. The cutting of the root part is carried out before and/or simultaneously with the separation of a rush seedling with a separation apparatus 14 to separate the root part (a) of a mother stock of rush seedlings G into small stocks.