Growing guide · Vegetable garden and berries
Onion
Allium cepa
1,277 ha of onion in 2025. At home easiest from sets in late May.
Key figures
| Item | Value | Source |
|---|---|---|
| Sowing / planting | sets late May – early June; soak 1 h in 40 °C water | [2] |
| Sowing depth | 5 cm furrow, tip showing | [2] |
| Seed rate / spacing | 10 × 20–30 cm (shallot 20–25 × 30–40 cm) | [2] |
| pH | 6.0–7.0 | [3] |
| Harvest | about 3 months; when half the tops have yellowed | [2] |
| Storage | +2…+5 °C | [2] |
The full guide (care, pests, beginner and professional tips) is currently in Finnish. The figures above are the same and come from the sources below.
These are general guidelines. Always check the variety, seed packet or fertiliser instructions and current regulations.