Onions are biennial plants. This is how they work:
Life Cycle of an Onion Plant
Year 1, Spring: | Seeds germinate and start to grow. |
Year 1, Summer: | First the leaves sprout, then the bulb at the base of the plant begins to swell. |
Year 1, Autumn: | The bulb, where the plant stores food reserves for the winter, reaches maturity, but the foliage dries up and dies. This is when the onion bulb is usually harvested. |
Year 1, Winter: | If left undisturbed, the bulb lies dormant all through the cold months. |
Year 2, Spring: | Answering the call of the springtime sun, the bulb sends forth a shoot which initially feeds on the food stored in the bulb, then sprouts leaves which aid in photosynthesis. |
Year 2, Summer: | The stem "bolts" (begins to elongate rapidly) and produces a bud. The bud blooms into a flower, which eventually "goes to seed". |
Year 2, Autumn: | The plant dies, but next spring the seeds can grow into new plants. |
Last spring I bought some onions from the supermarket and stored them in my kitchen cupboard. The cupboard is a dark, airless place, but even in such harsh conditions, life prevails. A few days later I discovered that one of the onions had begun to sprout.
Impressed by its will to live, I decided not to chop it up, and instead planted it in a pot.
The plant was undemanding – I just watered it every other day and fertilised it with coffee grounds. Still it grew steadily, putting forth leaves and in May, a pair of buds. But its tribulations were not yet over.
While I was on holiday in the USA, the pot was blown over by the wind. The plant lay ignominiously on its side, but undeterred by this misfortune, it bent upwards at a right angle and continued to grow. When I righted it, the stems – always reaching for the light – again bent upwards at a slightly higher point, giving the plant an interesting shape, a bit like a modernist sculpture. Here are some photos of the flowers in various stages of development.
At the time of writing, the flower petals are drying up. If the flowers have successfully self-pollinated, they may soon produce seeds. I think it's pretty cool that an onion bulb can flourish and reproduce even after being uprooted, sold in a supermarket and lying neglected in a kitchen cupboard.