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10 Secrets for Growing More Flavorful Onions

Onions growing in garden and at different stages

Growing onions is a simple process because they actually thrive in cool weather. Onions are typically sown in the early part of the springtime and harvested in the late part of the summer. When it comes to growing onions, whether you begin with seeds, sets, or seedlings, there are a few best practices that may make all the difference between a successful harvest and one that is less than satisfying.

Onion Growing Stages

Stages of growing onions

If you want to grow flavorful onions in particular, then you need to follow protocol on how to plant as well as how and when to harvest onions. Here are the 10 secrets for growing more flavourful onions:

1. Choose the Right Location for Planting Your Onions

Planting onions

If you want to cultivate flavorful onions, selecting the right spot to do so is absolutely necessary. Choose a spot that gets full sunlight and is free from other plants that might cast a shadow on your onions. If your onions can absorb extra energy from the sun, their bulbs will be able to expand to greater sizes. 

Soil onions thrive on soil that is just moderately rich, has good drainage, and is somewhat loose. Including organic compost in the planting, is a fantastic method to ensure that they will thrive in their new home.

To get a more desirable texture in the soil, incorporate compost or seasoned manure into the ground in the late autumn or early spring. Check to see that there aren’t any pebbles or other garbage. The soil must also have good drainage and be rather loose; bulb growth is negatively impacted by compacted dirt.

Weeds have an advantage when it comes to obtaining nutrients and water, which is why you need to remain on top of removing them. When working around your onions, though, be careful not to damage the roots by doing so too roughly.

2. Manage Pests

Pests on onion bulb

Many insects and animals are repelled by the pungent smell of onions, which is why some gardeners choose to cultivate them as a means of controlling pests in their gardens. As a result of this, they don’t often have issues with pests on their own, but this does not mean that they are completely resistant to bugs.

Some of the most frequent types of pests are thrips and onion worms. Row coverings may stop mature maggot insects from depositing their eggs, and thrips can be eradicated with an application of insecticidal soap. Row covers also protect against maggot flies. You may also prepare your own by mixing one teaspoon of mild liquid soap and one liter of water in a separate container.

3. Prevent Diseases

Diseased onion

Onions are often vulnerable to bacterial and fungal infections, but this is not typically a significant issue. The most prevalent diseases are downy mildew, blight, as well as soft rot. You should start to treat the bulbs or the foliage with an organic fungicide as soon as you see any signs of rot or white spots on them.

However, in many cases, the best effective therapy is to simply remove the diseased plant from the ground and kill it before it can infect other plants.

Onions are a crop that should be rotated regularly. It is important to avoid planting them in the same spot year after year, since doing so might promote the development of illnesses that are detrimental to the crop. Acquaint yourself with the concept of crop rotation to do this properly.

4. Properly Harvest Your Onions

Harvest of onions

Correctly harvesting onions also plays a big role in how the onions come out. To harvest your onions correctly, use the following tips:

Remove any blossom stems that appear on your onions. This indicates that the bulbs have completed their growth cycle. These onions won’t keep very well, but you should be able to use them within a few days. 

Onions that are planted in the spring often reach their harvesting maturity around the middle of the summer. As onions approach their full maturity, the tops of the plants start to turn yellow and eventually die off. When you reach this stage, you may hasten up the final ripening process by bending the tips down or even stomping on the leaves. To speed up the drying, you should loosen the soil all around the bulbs. 

If the weather is dry, harvesting should be completed by late July. Note that if some of the onions were wet harvested, they will not dry well and run the risk of rotting while in storage.

After the tops have become brown, remove the onions. Be very cautious while handling them, since even the tiniest bruising may accelerate rot, both now and while they are being stored.

Remove the roots, and trim the height of the tops to between 1 and 2 inches. However, make sure to leave the tops if you want to braid the onions together. 

5. Properly Store Your Onions

Storing onions

If the weather permits, let the onions dry for several days on the ground outside, or keep them in a dry, sheltered location like a garage or shed. After they have been cured, onions should be hung in a mesh bag or nylon stocking stretched out in a container or basket for up to two layers thick, or braided and hung in a location that is cold, dry and has enough ventilation. A temperature range of 40 to 60 degrees Fahrenheit (4 to 15 degrees Celsius) is suitable for storing most onions. Just don’t keep them in a refrigerator, since the environment is always too moist.

6. Check Your Onions For Signs of Rot

Make sure to always check the onions often for any signs of sprouting or rotting. If you find any rotten onions, remove them. It is not a good idea to keep onions alongside apples or pears because the ethylene gas that is generated by the fruits will cause the sterility of the onions to be broken. Furthermore, the onions have the potential to ruin the taste of these fruits.

The storage life of a pungent onion is much longer than that of a sweet onion. Because of their high moisture content, sweet onions do not store very well. Consume the milder variety initially and then go on to the more robust ones.

7. Knowing the Different Types Of Onion Plants

Types of onions

Knowing the different types of onions that are available can also help you determine what you should do to grow flavourful onions. There are several kinds of onion plants. They are usually categorized as red, yellow, white, and sweet at the grocery store where you shop.

However, there is a very wide variety of onions that you might plant on your own. The types of onions you can plant will be determined by the area you reside in, since not all types of onions can thrive in one location. 

Because onions are sensitive to the length of the day, it’s important to know which varieties will provide the greatest results in your area.

  • Short Day. If you have daylight that ranges between 10 to 12 hours, you can go for onions like Red creole, yellow garnet, red burgundy as well as white Bermuda. These onion types are mostly recommended for southern US gardeners. 
  • Day-Neutral: If you have between 12 to 14 hours of daylight, you may opt for onion types like Talon, Cabernet, Gladstone, as well as Sierra Blanca as they are suitable. 
  • Long-day: In northern locations that see days with more than 14 hours of light, some of the best alternatives include Spar, Red ballon, sweet Spanish as well as Cortland.

8. Ensure that Your Onions Get the Right Temperature and Moisture

Onions growing in raised tiered bed

Onions have rather shallow roots, therefore they do best under conditions of consistent wetness. Uneven levels might result in the development of undersized bulbs. If they don’t get enough water, they may flee, but if they get too much, they could rot.

As soon as the top inch of soil is completely dry, you should give them a drink to wet the soil, but you should never let it get soaked. Adding mulch around the plants’ bases is an excellent approach to help manage it and has a number of other benefits as well. A moisture gauge is another helpful instrument that may assist you in getting it to the ideal level.

At various stages of their development, onions have a range of temperatures that they like to be kept at. The temperature range of 40–70 degrees Fahrenheit is optimal for the establishment of young starts. They need warmth to initiate the process of bulb production. Temperatures of 75 degrees Fahrenheit or above are preferable.

9. Onion Set vs Onion Seed

Onion sets vs seeds (photos comparing the two)

When it comes to producing onions, you may find that you are presented with the option of either growing the onions from seed or growing them from sets. It’s recommended to plant onion sets rather than begin growing onions from seeds because sets get established more rapidly and need less effort to sow.

Onion sets are juvenile onions that will develop into full-sized onions after around 14 weeks. They are more likely to thrive than either transplants or seeds that were planted directly in the ground since they are more resistant to light freezing. The onion sets, which are offered at gardening shops and have the appearance of miniature bulbs, will, after they have fully matured, evolve into full-sized bulbs. 

Pick onion sets that have bulbs with a diameter of about 3/4 of an inch; bigger bulbs tend to grow necks that are too stiff to go to seed. Growing onions from seed may also be required in geographical areas with lower average temperatures. Because the soil temperature must be at least 50 degrees Fahrenheit for onion seeds to sprout, the seeds should be sown inside around six weeks before they are transplanted into the garden. 

If you are planting onion seeds, first plant them indoors about six weeks before you can transplant them to the ground, that is after the soil has reached a temperature of at least 50 degrees Fahrenheit).

The amount of time it takes for onions to mature from the time they are planted to the time they are harvested varies depending on how the onions were started. The longest time required is for seeds, which may range from three to five months. It might take between two and three months to grow onions from sets. 

10. Ensure Your Onions Get a Steady Nutrient Supply

healthy onions growing

Because onion plants are such heavy eaters, they must have a steady supply of nutrients to develop large bulbs. Put nitrogen fertilizer on the soil when you start planting. Before planting, a lot of people who grow organically would put an inch or two of compost at the bottom of every row. You may also create a trench in the ground that is about 1 foot long, 2 inches deep, plus 3 inches in width, and thereafter backfill the trench with around 1 foot of compost.

Put onion sets in the ground at intervals of two to six inches, pushing them lightly into the soft soil to a depth of not over one inch. If you wish to harvest juvenile onions to use as scallions, you should use the tighter interval. Furthermore, you should plant the transplants at a distance of 4 to 5 inches apart, then leave 12 to 18 inches between rows. Place the bulbs so that the pointy end is facing upward. 

Remember, you shouldn’t bury them any deeper than one inch below the surface of the earth. It is essential not to plant onions overly deeply, since this might have a negative impact on the growth of the bulbs. Straw should be used as mulch in between the rows to help prevent moisture loss as well as weed growth.

At the time of planting, mix slow-release granules or worm castings into the soil to provide your onions with a well-balanced organic fertilizer. This will give your onions a good head start. After that, give the soil a weekly dose of fish emulsion or compost tea, and finish it off with a monthly dose of granules.


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