How long harvest green onions?
Also to know is, how often can you harvest green onions?
Scallions can be harvested several times throughout the season depending on their level of maturity, with most people harvesting them once they are at least a half inch thick or anywhere from 8-12 inches tall.
Similarly, you may ask, how long do green onions take to grow?
20 to 30 days
If they do produce seed, to ensure seed purity you need isolation distances up to three miles. Finally, once you harvest the onion plant, it's gone. For all these reasons, consider some less common perennial onions. They're easy to grow and come back year after year, and you don't have to buy seeds every year.