Onions are more inclined towards cool weather in the early stages of its growth so it is planted in spring to provide it the temperature it needs. However, in mildly cold regions, onion is planted as a fall crop so it is started in autumn. On the other hand, onions can be grown year-round indoors too if the plant is provided with desirable conditions.
The aerial parts of the plant grow at cool temperatures whereas the onion bulbs develop during warmer conditions. The plantation of onion requires firm soil (either sandy loam or heavy clay) and a good load of water to allow the onion bulb to swell. Also, onion prefers to grow in a weakly acidic pH of about 5.5 to 6.5.
The location of growth must be sunny. For healthy bulbs, try adding compost or rich organic matter to impart nutrients to the soil.
Onion seeds are quick to germinate. Its seeds sprout within 4 to 10 days and within no time, onion bulbs are ready to be harvested.
Onion seeds send up the leaves that carry out photosynthesis and make their food to cater to the bulb growing underground. During spring, summer, and fall, the food accumulates in the bulb. Then in winter, this stored food helps keep the onion plant alive as it undergoes dormancy.
During the course of the second year of onion plants’ growth, the warm weather triggers it to send out flower stalks to produce flowers. From late summer to spring, the flowers bloom and get pollinated. By the time fall terminates, the flowers produce seeds that are saved for future onion yield.