gather
蒐 centers on bringing things together: gathering, collecting, or assembling items into one place.
蒐 combines 艹 (grass) with 鬼 (demon/ghost). The historical connection between these components and the meaning 'gather' is uncertain; it may be a phono-semantic compound where 鬼 contributes the sound.
Picture a demon 鬼 hiding in the grass 艹, gathering lost souls or collecting scattered items under the cover of the plants.
For シュウ, imagine a demon gathering shoes from the grass: shoes -> シュウ, and the demon collects them all.