short-day

short-day ▶adjective [ attrib. ] (of a plant ) needing a daily period of darkness of more than a certain length to initiate flowering, which therefore happens naturally as the days shorten in the autumn.

short-day

short-day ▶adjective denoting a plant that needs a daily period of darkness of more than a certain length to initiate flowering, which therefore happens naturally as the days shorten in the autumn.