🧅 Onion: Growing Guide
Onion (Allium cepa) grows best in full sun with moderate watering, and does well at 10–32 °C (50–90 °F) in soil with a pH of 6.0–7.0. Space plants about 10 cm (3.9 in) apart. Expect 100–175 days.
Quick facts
| Scientific name | Allium cepa |
|---|---|
| Category | Vegetables |
| Sunlight | Full sun |
| Watering | Moderate |
| Plant spacing | 10 cm (3.9 in) |
| Soil pH | 6.0–7.0 |
| Comfortable temperature | 10–32 °C (50–90 °F) |
| Time to maturity | 100–175 days |
| Sowing depth | 2 cm (0.8 in) |
| Height | 30–50 cm (12–20 in) |
When to sow, plant and harvest
The calendar below shows the best months in each climate zone. Pick the zone closest to your garden.
| J | F | M | A | M | J | J | A | S | O | N | D | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mediterranean | Sow | Sow | Plant out | Plant out | Harvest | Harvest | Sow | Plant out | ||||
| Continental | Sow | Sow | Plant out | Plant out | Harvest | Harvest | ||||||
| Oceanic | Sow | Sow | Plant out | Plant out | Harvest | Harvest | ||||||
| Subtropical | Sow | Plant out | Harvest | Harvest | Sow | Plant out | Harvest | Harvest | ||||
| Tropical | Sow | Plant out | Harvest | Harvest | Sow | Plant out | Harvest | Harvest | ||||
| Cold / Northern | Sow | Plant out | Plant out | Harvest | Harvest | |||||||
| Arid / Semi-arid | Sow | Plant out | Harvest | Harvest | Sow | Plant out | Harvest | Harvest | Sow |
- Mediterranean (Greece, Spain, Italy, coastal Turkey): Sow: Jan–Feb, Sep · Plant out: Mar–Apr, Oct · Harvest: Jul–Aug.
- Continental (Central/Northern Europe, inland Balkans): Sow: Jan–Feb · Plant out: Mar–Apr · Harvest: Jul–Aug.
- Oceanic (UK, France, Belgium, Netherlands, NW Europe): Sow: Jan–Feb · Plant out: Mar–Apr · Harvest: Jun–Jul.
- Subtropical (Southern US, N. Africa, Middle East): Sow: Jan, Aug · Plant out: Feb, Sep · Harvest: Mar–Apr, Oct–Nov.
- Tropical (SE Asia, Sub-Saharan Africa, Amazon): Sow: Jan, Jul · Plant out: Feb, Aug · Harvest: Mar–Apr, Sep–Oct.
- Cold / Northern (Scandinavia, Canada, Russia, Alpine): Sow: Mar · Plant out: Apr–May · Harvest: Jul–Aug.
- Arid / Semi-arid (Arabian Peninsula, inland Australia): Sow: Aug, Dec–Jan · Plant out: Feb, Sep · Harvest: Mar–Apr, Oct–Nov.
Watering
Water about every 4 days in summer and about every 10 days in winter. Reduce watering before harvest.
Growing tips
Grown from sets (bulbs) or seed. Cure in dry conditions before storing.
Good companion plants
These plants grow well alongside it:
Common pests and problems
Frequently asked questions
Onion: when should I sow and plant it?
Mediterranean (Greece, Spain, Italy, coastal Turkey): Sow: Jan–Feb, Sep · Plant out: Mar–Apr, Oct · Harvest: Jul–Aug. Continental (Central/Northern Europe, inland Balkans): Sow: Jan–Feb · Plant out: Mar–Apr · Harvest: Jul–Aug. Oceanic (UK, France, Belgium, Netherlands, NW Europe): Sow: Jan–Feb · Plant out: Mar–Apr · Harvest: Jun–Jul.
Onion: how often should I water it?
Water about every 4 days in summer and about every 10 days in winter. Reduce watering before harvest.
Onion: how far apart should I plant it?
Plant about 10 cm (3.9 in) apart and sow at a depth of about 2 cm (0.8 in).
Onion: how long does it take to grow?
Plan on 100–175 days.
Onion: which plants grow well with it?
Carrot, Rose, Lettuce, Beetroot.
Onion: which pests and problems should I watch for?
Thrips, Onion beetle.
Plan your garden
Add Onion to your garden design in the free GardenXPro planner: drag plants onto a 2D plan, preview it in 3D, check companions and get watering reminders.
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