Onion crop profile: sowing, temperatures, and harvest
OrtoClima crop rules for Onion.
Onion crop profile
Reference profile for starting onion, checking temperature thresholds, and estimating harvest timing.
Crop summary
- Starting method: direct sowing or transplanting
- Direct-sowing soil threshold: 2 C
- Transplant soil threshold: 2 C
- Night minimum: -2 C
- Frost buffer: -30 days
- Heat stop: 30 C
- Harvest range: 90-150 days
- Indoor lead: 77 days
How to start it
Onion can be started either by direct sowing or by transplanting. Direct sowing follows the soil threshold, while transplanting lets the first stage happen indoors.
For onion, start seedlings indoors about 77 days before transplanting.
Temperature thresholds
The operating thresholds are: direct-sowing soil at least 2 C; transplant soil at least 2 C; night minimum around -2 C.
The frost buffer allows considering starts up to 30 days before the cautious date, when the other thresholds are also met.
When maximum temperature exceeds 30 C, the window tends to close quickly.
Harvest timing
The estimated harvest for onion usually falls after 90-150 days; with transplants, the first stage can happen earlier.
This is a practical average: local climate, variety, exposure, and water management can move the first and last harvest dates.
Seasonal notes
- It can also work in autumn when local climate stays within the thresholds.
- The heat stop is relatively low, so late sowing can become risky in hot-summer areas.
- The negative frost buffer indicates a more cold-tolerant crop, as long as soil can be worked.
FAQ
Should onion start from seed or transplant?
The recommended starting method is direct sowing or transplanting. The main thresholds are direct-sowing soil 2 C, transplant soil 2 C, and night minimum -2 C.
What is the average harvest timing for onion?
The indicative harvest range is 90-150 days. The local page can move these dates according to the municipality and climate.
What climate limits does onion have?
The frost buffer is -30 days and the heat stop is 30 C. These values describe the crop's general needs; municipality pages adapt them to local climate.
How much indoor lead does onion need?
Yes. Start seedlings indoors about 77 days before transplanting.