Recycled Onions Would Flower and Make Seeds

The onions that were ‘re-planted’ in the garden are growing well. The onion tops are so green and a quite a number of the greentails have been clipped off to decorate salads.

Sorry to say so, but that is as far as we’ll get this year with these particular plants. Did you think we’d get a crop of new onions from doin’ that?

I have to admit I was hopeful that we would, but I didn’t understand that onions are biennials. That means it takes an onion 2 years to live its life completely. Here’s to the real life of an onion!

Life Cycle of An Onion, Allium spp.

  1. onion seed is planted
  2. seed germinates
  3. leaves grow
  4. roots grow
  5. bulb grows – esp. after a certain number of daylight hours is reached
  6. green tops fall over and die back in late summer
  7. overwintered – something happens
  8. plant leaves grow second year – in the garden or in the pantry
  9. flower stalk grows
  10. seeds made for a future generation
  11. bulbils form on seed head and drop to ground

If not harvested, the overwintered onion bulb can survive winter safely under ground. At this point the plant has stored enough energy to create new leaves and a long stalk for supporting a round head of flowers during the second year’s growth. Flowers will create seeds for a future generation of onions.

A secondary tack that the onion plant has for future-proofing its gene set is to create bulbils or mini-bulbs that naturally drop from the once flowering now seed head.

Either way it takes two years or two growing seasons for the onion plant to mature and complete its life cycle.

As gardener you may know that we can plant onions by seed or set. But where in this cycle is a set? Onion sets are small onions whose growth was arrested in Step 5.

Commercial producers of onion sets produce them by planting seeds very thickly or close together in a row which results in small onions that are harvested and dried and kept in storage until the following Spring. These so-called ‘onion sets’ are the dried bulbs we can purchase by the handful at most any garden center in early Spring.

Planting onion sets is like picking up the life cycle at step 5 above. Give them plenty of room and nutrients and they’ll grow a lot bigger, to be harvested the same year.

Taking the sprouting onions from the pantry is like picking it up in step 7 above. The plant is ready to produce the next generation so it develops the necessary parts to do so. It is no longer interested in creating the delicious bulb that we eat whose purpose was to store energy for creating the flowering tops.

So, what shall we do with our greentails in the garden? I’m going to leave a few plants near the edge just for the purpose of snipping off some onion greens, but the rest will be raked out so something else can be planted there instead, perhaps tomatillos or cabbage.

Green tail onions are nice, but only when they’re fresh. We’d rather have some large onions for slicing or storing, so we’ll plant some baby onion sprouts to take their place in the garden.