DibbleGrowing onions: from seed to harvest
Start seeds indoors about 8 weeks before planting out, or use sets. Match the variety to your day length (short-day types near the equator, long-day types far from it) and plant out in the cool part of the year. Cure the bulbs in dry weather once the tops fall over.
Planting dates for onions by zone
| Zone | Start seeds indoors | Sow or transplant | Harvest |
|---|---|---|---|
| Zone 3 | March 5 | April 30 | August 8 |
| Zone 4 | February 27 | April 24 | July 31 |
| Zone 5 | February 20 | April 17 | July 25 |
| Zone 6 | February 14 | April 11 | July 20 |
| Zone 7 | March 14 | May 9 | June 27 |
| Zone 8 | September 4 | February 14 | May 23 |
| Zone 9 | September 26 | November 21 | March 4 |
| Zone 10 | September 24 | November 19 | March 1 |
| Zone 11 | September 26 | November 21 | March 1 |
Each date is the start of the best window from the same climate engine the Dibble app uses, run at typical places in each zone. Dibble tunes them to your garden's own location and lets you adjust frost dates for your own yard.
Companion plants
Good neighbors for Onion:
Better kept apart:
Family and rotation
Onion is in the alliums family. Light feeders that deter pests. Good rotation partners; keep away from beans and peas. Learn about crop rotation.
Related crops
Garlic
When to plantChives
When to plantLeek
When to plantGreen Onion
When to plantShallot
When to plantTomato
When to plant
Questions
When should I plant onions?
It depends on your zone. Onion is a hardy crop, so the timing follows your last spring frost. Look up your zone in the table below for exact start, sow, and harvest dates, or open Dibble and set where your garden is to get your own calendar.
How long does it take to grow onions?
About 100 days from transplant to the first harvest, with a picking window of roughly 14 days after that.
What grows well with onions?
Good companions include Carrot, Beet, Lettuce, Tomato. Keep it away from Bean (bush), Pea.
Plant at the right time this season
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