Skip to content

Onion Growing Stages : The Gardener’s Guide

The Gardener's Guide to Onion Growing Stages

Understanding the Onion Growing Stages

Check out How to Grow Lots of Ginger in Containers here...

Hey there, fellow garden enthusiasts! Today, we’re delving deep into the fascinating world of onions. Understanding the onion growing stages can seem a bit perplexing, but fear not! We’re here to demystify the process and make it burst forth with clarity. So, grab your gardening gloves, and let’s embark on this green journey together.

Onion Onion Growing Stages : The Gardener's Guide
Image source – Olha_Afanasieva from Getty Images

What Are the Stages of Onion Growth?

Onion growing stagesOnion growth can be divided into four distinct stages: germination, seedling, vegetative growth, and maturation. Let’s break down each of these stages and sprinkle in some gardening wisdom along the way.


The journey of an onion begins with germination. Just like any other seed, the onion seed needs a bit of tender loving care to sprout. During germination, the seed’s outer layer peels away as moisture and heat kickstart the embryo’s development. Depending on various factors like soil type and moisture, germination can take anywhere from one to two weeks.


Once our baby onion has sprouted a few adult leaves, it’s officially a seedling. At this point, it’s also busy developing its root system. Onions prefer well-draining soil since their roots are shallow. If your soil is clay-heavy, adding some sand can prevent clumping.

Seedlings continue to grow leaves and roots until they’re ready to shift gears into intense vegetative growth.

Vegetative Growth

In the vegetative growth phase, our onion buddy starts producing leaves at lightning speed. From just a few small leaves, it shoots up to a robust count of eight to ten leaves. This phase comes to a halt when the onion is ready to focus its energy on forming the bulb.


Maturation, also known as “bulb initiation” is when the onion goes all-in on growing that bulb. After a few weeks, you’ll actually see the top of the onion as the bulb pushes out of the ground, and the leaves gracefully flop over. It’s a beautiful sight!


Once your onion reaches this stage, it’s time to say hello to harvest time. These onions won’t grow any further, so it’s wise to pick them. After harvesting, you can dry and store your onions for later use or even sell them if you’re feeling generous.

And just like that, we’ve covered the four main stages of onion growth! But hold on, there’s more to explore.

Check out How to Grow And Care For Collard Greens here...

What Is The Onion Life Cycle Like and When Should You Harvest?

Onions live life in a two-year cycle, similar to many other root vegetables. This unique cycle allows them to channel all their energy into growing lush green leaves and stashing away reserves for the next year – and that reserve is what we call the bulb, the tasty part we all love.

Farmers typically harvest onion bulbs at the end of the first year when they’re at their prime size. Left to their own devices, onions would sprout a flower in the spring and divert their energy, causing the bulb to shrink. This phenomenon is known as “bolting” or “going to seed,” and it’s not the goal here. So, remember to harvest your onions before they embark on this unexpected journey!

What Are The Planting, Harvesting, and Growing Specifics of Different Onion Types?

Now, let’s explore the intriguing variety of onion types and their unique characteristics. Check out this handy table:

Onion TypeAlso Known AsPlanting TimeHarvest TimeGrowing Method
GreenScallionsEarly springEarly (while immature)In bunches
WhiteCommonEarly springFallAlone
YellowCommonEarly springFallAlone
PurpleCommonEarly springFallAlone
SpringJust a baby common onionEarly springEnd of spring or early summerAlone or in bunches

Check out 10 Easiest Vegetables to Grow at Home here...

Onion growing stages FAQs

Q: What Are Onion Seeds?

Onion seeds are the tiny vessels that allow onions to reproduce. But unlike beans or peas, you can’t just sow them directly in the ground. Instead, start by growing onion seedlings in a greenhouse container for six to eight weeks before transplanting them into the soil. Onions thrive in cold weather, so aim for temperatures consistently above 28°F for optimal growth.

Q: What Are Onion Sets?

Onion sets are small onion bulbs from the previous year. They’re perfect for impatient gardeners because they yield onions faster. However, be cautious as they’re more likely to bolt due to their age.

Q: What Are Onion Transplants?

Onion transplants are juvenile onions that have been commercially grown from seed and are ready for planting. They skip the long germination and early growth stages, making them ideal for beginners. Plant them when the soil temperature consistently stays above 28°F for the best results.

Q: What is the Difference Between Spring Onions and Green Onions?

Spring onions and green onions are two different types of bulb vegetables. Green onions, also known as scallions, are harvested early and have no bulb, just a white stalk. Spring onions are common onions harvested early in the season, and they have a bulb that you’ll want to pick when it’s about an inch in diameter.

Q: What Colors of Common Onions Are There?

Common onions come in various colors, including purple, white, and yellow. When planting from transplants, the color matches the juvenile bulbs. If you’re using seeds, the packet should indicate the bulb color. If in doubt, let the onion grow, and you’ll soon discover its hue.

Check out How to Grow and Care for Lettuce here...


Onions are a fantastic choice for budding gardeners, especially in regions with a distinct cold season. They’re versatile, low to the ground, and available in both fast and slow-growing varieties. Whether you opt for transplants, seeds, or sets, understanding the onion life cycle is the key to successful onion cultivation.

In this article, we’ve covered essential points:

  • Choose between transplants, seeds, or sets before getting started.
  • Explore the four onion growing stages: germination, seedling, bulb growth, and maturation.
  • Discover the difference between full-size common onions and spring onions.

So don’t be afraid to dip your toes into the world of gardening. Plant some onions around your garden, toss them into containers on your porch, and watch your garden burst forth with life. The possibilities are endless, just like the joy of gardening itself!

Happy gardening, folks! 🌱

3 thoughts on “Onion Growing Stages : The Gardener’s Guide”

  1. Pingback: Grow Endless Green Onions for Your Kitchen! -

  2. Pingback: How Long Do Onions Take to Grow - Back Gardener

  3. Pingback: How Long Does It Take for Onions to Grow - Back Gardener

Leave a Reply

Your email address will not be published. Required fields are marked *