In most cases, green onions are actually bulb onions that have not reached full maturity.Â You can grow green onions from most standard onion varieties.Â If you grow large batches of onions, you can actually harvest a few of your onions early as green onions and then let the rest form bulbs for a later harvest.Â This is a useful technique for thinning your onion plot as well.Â
There are some varieties of onions such as Beltsville Bunching that will actually not form bulbs and are used specifically for green onions.Â They form groups of thin root-like structures instead of bulbs.Â These are often referred to as â€œbunchingâ€ onions or scallions.Â
You can harvest green onions when the tops of the onions grow to about 5 inches high.Â The longer you let them grow, the more potent their flavor will be.Â Take into account that if you leave them for a long time the flavor may be too strong for salads, etc.Â Youâ€™re best to cook these onions rather than eating them raw.
You can harvest the green parts of the onions about a month after planting sets.Â Transplants will also provide green onions about a month after planting.Â Some onion varieties are better than others for growing green onions.Â Please see our list of recommended onions for the best ones to grow green onions.
Be warned that bolting, or when the plants start to produce flower stalks, can happen under certain circumstances when growing onions.Â In these cases, itâ€™s best to pull out these plants as soon as possible and use the green onions.Â Unfortunately, you wonâ€™t be able to use these onions as bulb onions.Â