How to Plant Onions at Home: The Complete Guide

Do you want to enjoy fresh, home-grown onions? Then let me tell you good news! 

Growing onions is one of the easiest gardening tasks you can do.

You might wonder how to grow them well!

You can grow your own fresh onions in your garden with little care. Onions require minimal space to thrive and give reliable harvests that can be used in all kinds of dishes. 

In this blog post, we will guide you on how to plant home-grown onions in a small space with minimal care and different types of growing methods you can adopt. We will also offer you some extra tips to ensure a successful harvest.

How To Grow Onion Bulbs

You can grow onions from seed, transplants, and small  immature bulbs called “sets”. Onion bulbs form due to fluctuating temperatures and day length. The local climate and latitude will determine which onion types will grow best in your area and when the best time to grow them. For instance, in northern areas, Onions are planted in the spring for a late summer or fall harvest. In southern areas, you can sow onions in the fall or late winter for an early summer harvest.

1. Growing Onions from Seed

Growing onions from seed is considered the cheapest method as well as it provides the greatest availability in terms of variety selection. However, it is the most difficult practice, with uneven germination is quite common with growing onions from seed. But don’t be discouraged! With proper planning and care, you can successfully cultivate a bountiful onion crop.

To increase your chances of success, Start seeding indoors 10-12 weeks before the expected transplanting date. Use a seed-starting mix and provide adequate light. Once seedlings have developed a few true leaves, transplant them into individual pots or biodegradable peat pellets. For northern gardens, you can start to sow in early spring as soon as the soil is workable. In southern gardens, direct sow seeds in fall or late winter.

2. Growing Onions from Sets (small immature bulbs)

You can grow onions by using sets. The sets are small immature bulbs that are pre-grown and ready to be planted. This method is most popular for fast growing and more reliable harvest compared to starting from seed.  However, it’s important to note that plants may be susceptible to bolting or premature flowering.

To maximize your harvest, choose sets that are no larger than an inch in diameter. Smaller sets are more likely to establish quickly and produce a better harvest.

Sets are widely available in agriculture centre’s or can be ordered from seed catalogs. However they are more expensive if you compare them with seeds and the variety selection of sets is extremely limited.

When to Plant Onion Sets

Spring planting: This is the most common method widely adopted in the world. The onions are planted as soon as the ground can be worked, usually late March or early April. 

Fall planting: A few varieties are suitable for fall planting. Check your local climate conditions because this is not ideal in every part of the country. 

3. Growing Onions from Transplants

Onion transplants are basically seedling onions purchased from seed companies. They come in small bundles of dormant plants, each plant is about as thick as a pencil. Onion transplants are more reliable than sets and are less prone to bolting. Additionally, transplants also offer advantages over starting from seed, as they typically grow faster and have a better chance of sprouting.

Transplants are also widely available in catalogs and offer a wide range of varieties. Both transplants and sets can be grown in the garden when soil temperatures reach 50˚F, about 4-6 weeks before the average last frost in spring. 

What is Seedlings? Seeds can not be stored usually well, so Germination is the process by which a seed develops into a new plant so called Seedlings. They are in the initial stages of a plant’s life cycle and usually require close attention during development.

Essential Steps for Successful Onion Growth

Prepare the Soil:

• Choose a well-drained site where to plant the onions. Full sunlight is the best, however.
• Clear weeds and debris from the planting area.
• Enrich soils as needed with well-composted organic matter to enhance soil fertility and structure. 
• Add fertilizer as recommended and ensure the bed is ready to support healthy plant growth.

Create Planting Beds:

• Create mounded rows for improving drainage (if necessary). This technique will help to prevent waterlogging and support better root development.

Plant Onions Step-by-step:

• Decide whether to start from transplants, onion sets, or seeds.
• Insert transplants or onion sets 1 to 1½ inches deep .in furrows spaced 12 to 18 inches apart
• 4 Inch transplants along the planting furrow at 4-inch intervals.
• Space transplants at a 4-inch interval along the planting rows.
• When choosing for direct seedling, sow seeds about  ½ to ¾ inches deep, with 8 to 12 seeds per foot of row. 

Care for Onions:

• Take good care of newly planted onions by watering them, especially in dry season.
• Keep a watch out for weeds around the onions at all times, and destroy when necessary.
• Mulching around plants helps to keep the soil moist and keeps weeds at bay.
• Protect onions from pests and diseases.

Additional Tips:

• Consider the use of row covers to give the young seedlings buffer protection against frost and pests.
• Your spring-planted onion bulbs will be likely harvested in 3 to 4 months. The tops of the onions will start to show yellow tint and the leaves will start to fall over. This will be a signal that it’s harvesting time.
• Once you see a good amount of onion stalks have fallen over, go ahead and bend over the rest and wait a few days before harvesting.

Is It Better to Grow Onions From Sets or Seed

You can start onions from seeds or sets, both methods will work. I would recommend you to start onions from seed only if you have a greenhouse (warm space) and some gardening experience under your belt. Growing from seed takes more time and is more challenging for non-experienced gardeners, but it is less expensive and offers a wide range of onion varieties to choose.

I like to start my onions from seeds because I have my own greenhouse where I can start them. After they grow a bit, I transplant them into my garden.

It is easy to grow onions using onion sets because they are so fast and convenient. Onion sets are immature bulbs that can be directly planted in your garden. Plants grown from sets have less chances to be attacked by disease. However, they are more prone to bolting (when a flower is produced instead of a bulb), so it is advisable to buy heat-treated sets to reduce this risk. Sets offer fewer varieties compared to seeds. They often come in large packs, If you cannot use them all, you won’t be able to store them for the next year.

Short Day Vs. Long Day Onions

When buying onion sets, you need to choose the right type for your area. There are three types of onions: Short-day, Long-day, and Intermediate-day onions.

The type you need depends on where you want to grow them. Each type of onion requires a different amount of sunlight hours to trigger them to bulb up. Make sure to choose the one that matches your local climate. Picking the right onion is important for growing big, tasty bulbs.

Conclusion

After considering all the factors, you should now know how to plant onions in your garden. It is a very simple process. Whether you choose seeds, sets, or transplants, you can easily grow delicious, fresh onions right at home. Just ensure you pick the right type for your local climate, and provide proper care. With a little attention, you will be rewarded with a great harvest. So, have fun with the process and savour the flavourful results!

FAQs