Onions are biennials, and will flower the second year. Sprouting storebought bulb onions, if planted, will continue to grow leaves and then a flower stalk. Eventually, it will form seeds. These seeds can be planted the next year, although they may not produce onions that contain the same characteristics of the original; also, the variety of onion may not grow well in your area. However, you can harvest the onion leaves when young, for salads etc. The old, mature onion will not make more onions—only through its seeds.
However, bulb onions can be regrown by cutting off the bottom inch or so that contains the roots and planting it. These will form leaves and bulbs eventually, if the onion variety is appropriate for your climate.
You can regrow green onions by harvesting the tops and replanting (or placing in a jar of water) the bottom bulb with roots (about 2 inches in length); the leaves will grow back for you to harvest again.
Onions are biennials, and will flower the second year. Sprouting storebought bulb onions, if planted, will continue to grow leaves and then a flower stalk. Eventually, it will form seeds. These seeds can be planted the next year, although they may not produce onions that contain the same characteristics of the original; also, the variety of onion may not grow well in your area. However, you can harvest the onion leaves when young, for salads etc. The old, mature onion will not make more onions—only through its seeds.
However, bulb onions can be regrown by cutting off the bottom inch or so that contains the roots and planting it. These will form leaves and bulbs eventually, if the onion variety is appropriate for your climate.
You can regrow green onions by harvesting the tops and replanting (or placing in a jar of water) the bottom bulb with roots (about 2 inches in length); the leaves will grow back for you to harvest again.