Overwintering onion sets planted on shallow ridges in a UK raised bed (Zone 8a), 10 cm spacing and light mulch visible.

Overwintering Onions in the UK (Sept–Oct): Senshyu, Radar, Electric — exact spacing, depth & timing

Plant overwintering onion sets in September–October (UK). Exact depth (≈ 2 cm), spacing (10 cm; rows 20–30 cm) and best varieties—Senshyu, Radar, Electric, Snowball—plus clay fixes, container layouts, and how to prevent bolting and downy mildew.

My Gardening Journey