It is not uncommon to see onions with flowers. You can grow onions from seeds, young transplants, onion bulbils or onion sets.
Flowers in onions are to be expected in onions that grow from sets, but transplants, and onions grown from seeds, should not flower if properly grown in ideal climate.
Onion sets are bitty little onion bulbs grown from seeds in last years planting. The farmer harvests the small bulbs and stores them throughout the cold season in dormancy.
Plant stores and gardens sell them to other onion farmers in the spring, for replanting in the ground as onion sets.
The proper diameter size of the onion bulb onion sets is smaller than a nickel, but your chance of flowering will increase if they are bigger sets.
Unfortunately, the onions that flower produce also small bulbs and they are good to eat as green onions.
What is bolting in onions?
Onions are said to be bolting if they are flowering too early or if they are not grown from sets. Once onion produces the flowering stalk the bulbs quit growing.
The flowering stem and seed use all the nutrients to develop the bulb instead of developing the bulb before flowering.
Stress is the main reason for bolting onions. Stress from the climate or other factors makes the onion plant react by suddenly reproducing when it receives some stimulus.
This stimulus is bad for the plant and causes the bulb to stop bulb development.
The lifecycle of onions
Onions are a biennial species of plant.
Biennial means it takes the plant a year to grow and develop flowers the second year. “Bolting” refers to onions that flower in the first year of growth.
During the first year of growth, onions are establishing an underground bulb and need nutrients and sunlight to grow.
At the start of winter, the leaves of the onions will die off, and the bulbs go dormant.
At the end of the first year, with the leaves dying off, it is time to harvest the onion bulbs. Onion farmers may choose to leave them as is.
They will go dormant in the winter and begin to grow back to form flowering stalks at the start of their second year.
Since the onion plant has completed a life cycle, they will begin to flower in their second year. If harvested at the end of the first year, the new crop will not flower.
Weather or environmental changes can Oto add to a flowering of an onion plant or seed. Another big issue is sometimes it causes flowering or seeding in first development season.
Causes of early flowering in onions
Onions that are flowering are either in their second season of growth, or they are flowering prematurely.
There are many possible causes for early or premature flowering in onions.
They include:
Sudden temperature drop
Following their initial planting, onions will start to mature as the warm season builds.
These bulbs will grow continuously and slowly through the winter.
However, there is a point when the onion will stop growing if an unexpected cold snap occurs.
A cold snap causes the onion plant to believe it is completing the growth cycle and entering the dormancy period although the bulbs are still very small.
Warm weather just before winter
Winter brings a temporary halt in growth for onions; so if the temperature shoots up after a cold spell, it can confuse onion plants.
They can get tricked into thinking it is time for a second season and begin to flower and produce seeds.
Ways to prevent onions from flowering
The best way to limit eating onions with flowers in your garden is through correct timing.
If you plant your onions early enough, they will be ready for winter when the size is proper.
They will have matured enough and become dormant until next season. The following season, these onions will grow without producing flowers.
If you plant your onions late, they won’t have matured enough for winter; Seedlings less than 5 inches in length are not mature enough to withstand the big temperature changes through the seasons.
They will go into dormancy too early when they produce stalks that flower in the new season, second season.
The planting of onions vary greatly depending on where you are located throughout all states in the US. You need to consult your zones before starting your onions.
The zone markings will also determine if you will plant onions from seeds, transplants, or sets.
The downside of not taking into account your climate conditions is producing flowers too early before the first season has come to an end.
Keep in mind – Late planting, however, may lead your onions to produce small bulbs. Alternatively, the young seedlings will not survive as weather conditions play a significant role in onions during winter.
You can consider covering your onions using a plastic tarp or growing them in a greenhouse to avoid sudden moving of the temperature.
Proper watering of onions in the warmer months will maintain the temperature of the earth and soil below ground. Moist soil conditions will feed the bulbs, keep growing bulbs until they are ready to grow through winter.
You should also compact the earth where the onion plants grow. Loose soil will hinder root development.
The roots grow not getting their required nutrition, and the young plants will cease their development and cause great stress at this developmental stage.
After that, the use of fertilizer means something directly to your onion plants. They will ingest excess nutrients and make them overgrow in the warmer months.
These bulbs will grow too large too soon and initiate growing of the flowering stalk. Use fertilizers with moderation when needed and only after the bulb has fully grown.
Can you still harvest onions with flowers?
Absolutely!
You can still save your onions even if they produce flowers.
Once the onions bolt, they will stop growing as an underground bulb. If you harvest them, they will spoil quickly.
Since the onions will start to rot, you can harvest them and cut off the leaves and flower stalk.
To cure them, lay them out to dry in a warm, airy and dry area. Once you have cured them, make sure you eat them in the shortest time possible.
You can also replant the seeds from the onion flowers into new plants. This means new seeds, which is a money-saver, and an unexpected bonus from bolting.
Onion flowers are also an interesting ingredient in infused oil and vinegar. The beautiful color makes a statement on a plate.
The green flower stalks from your bolting onions can take the place of leeks or green onions.
Chop off a few and toss them into salads or stir fry recipes. Throw them into noodle soup and stir fried eggs for a delicious onion flavor.
Conclusion
While it may seem discouraging, if your onions flower, it doesn’t mean you’ve lost your entire crop. You can harvest the flowering crops and use them right away to prevent them from rotting.
Simply cutting off the flowering stalk will not save your onion plant. The stalk actually grows through the bulb underground, so it is best to harvest them.
For the future, just remember to select the proper onion varieties for the climatic conditions of your zone.
The southern areas of the United States typically grow the short-day type of onion. This type makes bulbs that need about 12 hours of daylight. Short-day varieties include Red Burgundy and Gabriella onions.
The northern sections of the United States grow the long-day type of onion. These onions need about 15 hours of daylight to form bulbs. Long-day varieties include Walla Walla and Dakota Tear’s onions.
Lastly, the central parts of the United States grow day-neutral onions. They make bulbs regardless of daylight conditions.
Common day-neutral or intermediate onion varieties are Carbanet Red and Gladstone White onions.
As the onions grown from sets are more home to bolt, you should only plant large sets. They will develop into bulbs faster, allowing you to harvest the not-yet-bolting bulbs.