One staple ingredient for cooking is an onion bulb, a vegetable type of plant that adds aroma and flavor to a raw or cooked meal. Onions are quite popular for their edible bulbs. But, you can also eat the onion tops and their flowers.
The fact that onion plants are one of the oldest cultivated plants in the world says so much about their importance to human life.
And if you’re someone like me who loves to consume a bulb or two every day, including onions in your vegetable garden is worth it. Here’s an article to guide you:
What are Onions
If you’ve heard the phrase, Allium cepa, that’s an onion botanical name. This plant species is native to Asia but is now cultivated worldwide due to its wide use in culinary. Onions belong to the Alliaceae family.
They’re considered biennial because they need two years to complete their life cycle. In the first year, they produce bulbs and then bear flowers and seeds the next year. However, most growers treat onions as an annual plant because they harvest them on the first after the bulbs are formed.
Choosing Onion Varieties
There are different types of onions you can plant depending on your preferences and purpose. The varieties may differ from each other in terms of shape (round, flat, or globe), color (red, white, brown, yellow), and taste (sweet or pungent).
The red onions are the most popular and are best eaten raw. The flavor is strong and you can use them on guacamoles, pickles, and salads. The green onions (scallions) are the young onion leaves specifically used for toppings and garnishings.
For frying and roasting, sweet onions are typically used. Yellow onions are the ones used for all-around cooking, especially with sauces, soups, and stews.
You also need to choose a variety that’s well-suited to your climate to maximize onion production. For example, long-day onions need about 14 to 15 hours of daylight to form full-sized bulbs. So, they tend to grow better in the Northeastern part of the US.
Short-day onions, on the other hand, need 10 to 12 hours of daylight, which is present in the South of the US. There are also day-neutral onion varieties that you can grow in any zone.
When Is The Best Time To Plant Onions
There are different times to start onions depending on what variety you are planting. For short-day onions, plant them during the fall season, grow through winter, and expect to harvest in late spring. For long-day varieties, plant onions in early spring, then harvest from mid to late summer.
For day neutral, plant onions in early spring if you’re residing in a colder region. If you’re in a warm region, plant onions in the fall.
Preparing Soil for Onion Planting
In general, onion plants thrive in well-drained soil that has a pH of between 6.0 to 6.8 (slightly acidic) and is rich in organic matter. They are best grown in raised beds that are a least 4 inches high and 20 inches wide.
Work on the soil to prepare them for planting onions. Disintegrate the compaction to provide good aeration and achieve a loose soil structure. It’s best to start doing this when the soil is not too wet or frozen.
Add organic matter such as well-rotten compost. But be careful not to add fresh manure because it may contain pathogens that can cause diseases in your onions.
Planting Onion Sets or Seeds
There are two ways to start your onions. You can plant onions directly from seeds or transplant onion sets into the ground.
For direct seeding, sow onion seeds into a 2-inch wide band that has a depth of 1/4 to 1/2 inch. You have to sow the seeds in rows with a distance of 12 to 18 inches apart. Once the seedlings emerge, thin them out to 3 to 4 inches apart.
Make sure to retain only the vigorous onion seedlings. To ensure good quality planting materials, buy certified onion seeds only from reputable sources. If you don’t want to start with seeds, you can also use onion transplants from nurseries.
Onion transplants are pre-germinated and you only have to transfer them to the soil.
Another method is to use onion sets, which are immature bulbs grown from last year. Before you plant onion sets, be sure to choose compact onion bulbs so they won’t grow overly big at the time of harvest. Plant onion sets outdoors at a depth of 1 1/2 inches and then a distance of 3 to 4 inches apart.
Put a few inches of mulch on top of the soil using straw or shredded leaves to help conserve soil moisture and suppress the growing weeds.
Caring for Onion Plants
How Much Light Does An Onion Need
Onions grow best under full sun so the ideal location should be outdoors. Ensure that the area has no light obstruction and that it receives full sun at least six hours daily. Remember that long-day onions and short-day onions have specific length requirements for light to form bulbs.
When to Water
Onion plants have shallow roots. Hence, you must maintain moist soil. Water onions deeply once a week to ensure good growth. If you provide at least an inch of water per week, it’s enough to wet the soil at a depth of 6 to 10 inches.
When there’s rainfall, you can skip manual irrigation. Overwatering can cause bulb rot.
Once the onion bulbs reach their full size and the tops are beginning to wilt, you can stop watering your onions.
Ideal Temperature
Onions prefer a temperature between 60 to 77°F (20 to 25°C). For the germination of seeds, the environment needs to be at least 40°F(4°C).
Humidity Levels
Humidity isn’t a big concern for growing onions as long as you provide the right soil moisture.
When to Fertilize
Onions are heavy feeders and they need a consistent supply of nutrients to produce big bulbs. Three weeks after planting, apply one cup of nitrogen fertilizer per twenty feet of row. Always apply fertilizer six inches away from the plants to prevent fertilizer burn.
Then, water the soil deeply after feeding to dissolve the release the nutrients and ease their absorption. Repeat application every 2 to 3 weeks.
Once the neck starts peeling, it’s time to cease the application of fertilizer. Most likely, this is to happen about 4 weeks before the onions are ready for harvest. So, make sure to observe your onions closely.
Managing Pests and Diseases
Onion root maggots are one of the serious pests of onions. The larvae enter the leaf sheaths of the green onions and then enter the bulb. From there, they feed on the roots, stems, and young bulbs, causing significant damage, and worse, death of the whole plant.
One way to prevent the infestation of onion maggots is to practice crop rotation. You can also delay the planting and wait for the first flight to finish and the soil temperatures are high enough to kill the eggs (95°F or 35°C). Maintaining ample space between onion rows will also help prevent heavy infestation.
Aside from pests, diseases such as fusarium basal rot, botrytis neck, and bacterial soft rot may also infect your onions. Choosing resistant varieties will help you avoid these problems in the future.
Harvesting and Storing Onions
Mature onions will be ready for harvest once half the top of the leaves are dry and have fallen over. Lift the bulbs out of the soil using a spading fork. When harvesting onions, be careful not to damage the bulbs so they won’t rot when stored.
Allow the harvested onions to dry, clip the roots, and cut the tops back to an inch.
Curing is an essential process if you’re planning to store onions for a long time. After you harvest onions, keep them in a well-ventilated area that has a warm temperature between 75°F to 95°F (24 to 35°C). Wait for the scales to dry and for the neck to tighten.
This will take about 4 weeks. After the curing, you can braid the tops and store your onions in a cool, dry area. Don’t store them in a fridge.
Conclusion
Growing onions requires patience, especially if it’s your first time doing it. However, it’s also gonna be a rewarding feeling once you start to harvest onions from your own vegetable garden.
Whether you want to buy, sell, or simply reach out to other plant enthusiasts, Plantly is the right place to be!
