Onions typically grow to be 12–18 inches tall.
According to The Spruce, onions (Allium cepa) from the Amaryllidaceae family, usually reach a height of 12 to 18 inches and a width of 6 to 12 inches. This size refers to the above-ground foliage.
| Characteristic | Details |
|---|---|
| Height | 12–18 inches |
| Width | 6–12 inches |
| Plant Type | Biennial, vegetable |
