Seeds to sow in September

September is the start of a new growing rhythm. Warm days often continue, but cooler nights make it important to pick the right seeds for the season ahead. Focus on hardy crops, fast leafy greens, and varieties that grow well under cover. Greenhouses, cold frames and cloches become especially useful now, helping you keep growth going for longer. September sowing can set you up for fresh harvests into autumn and, with the right protection, even into winter. Browse this collection for seeds that suit September conditions and keep your garden productive beyond summer.