From Seeds to Sprouts: Tips for Growing Onions

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Ever felt the pain of watching your onion seeds rot in the ground, or wondered why your onions never get as big as the ones at the store? Growing onions from seed can be tricky, but luckily there are some tips and tricks that can help you grow healthy, delicious onions successfully.

Here, In this guide, we’ll show you some surprising tips for growing onions. You’ll learn what type of soil helps onions grow best, how to care for onions during different stages of growth, and what common mistakes to avoid.

Different Types of onion:

There are numerous ways to differentiate onions like color, shape, size, etc. But we will discuss the main three types of onions based on their maturing period. These are:

  • Short-day onions
  • Long-day onions, and
  • Intermediate-day onions.

Short-day onions are onions that require 10-12 hours of daylight to form bulbs. They are best grown in the Southern States (a latitude of 25-35) where the day length is closer to 12 hours. Short-day onions can be grown in other parts of the country, but they will not bulb as well.

Long-day onions require a longer growing season. They would need at least 14-16 hours of light every day. these onion varieties are perfect for you if you live in the northern states (a latitude from 37-47). They are also very good for long-term storage.

Intermediate-day onions take 12-14 hours of daylight to mature. They perform best in Zones 5 and 6. Ideally, the maturity is reached in 110 days from transplanting.

Choosing the right onion variety

To determine which onion type is right for you, consider your climate and the length of your growing season. If you live in a warmer climate, short-day onions will do well.

If you live in a cooler climate, long-day or intermediate-day onions may be a better option.

How to grow A onion plant

You can grow onions from

growing onions from seed:

If you are planning to start with the seeds, it is better to first grow the seedlings indoors. Use special seedling trays (or can alternatively opt for used Egg cartons) and good quality potting soil.

If you are planning to buy transplants from the market, talk to your nearest garden center or nursery shop. Though in transplant, the choice of variety is limited, the survival chances are pretty high.

Growing from Onion sets:

You can also use immature bulbs also known as onion sets. The best part of choosing bulbs is that they are easy to plant, less disease prone, and the earliest to harvest.

Choose bulbs that are smaller in size (diameter less than ½ inches). The big-sized bulbs are much more prone to bolting.

Planting Onions:

If you want to have a successful onion crop, it is important to plant them correctly. Follow these steps and you will be rewarded with a bountiful harvest.

Where to plant onions?

Onions like sunny spots in the garden, so choosing the right location is important. They grow best in light soil that is amended with organic matter.

Raised beds are a good option for onions. It provides warm soil and ideal air circulation to the plant. You can also amend the soil quite easily.

Plant the onions at the depth specified on the seed packet, and space them according to the variety you are growing.

Preparing the best soil for onions:

To have a successful onion crop, you must first prepare the soil. This starts with testing the soil pH and making sure it is in the ideal range for onions. A soil test kit like this is the easiest way to test the pH of your soil.

Start with well-drained, loose soil. Onions do not like soggy conditions, so make sure the area you choose to plant onions has good drainage.

Onions prefer slightly acidic soil, the ideal pH range should be between 6 and 7. Once you know your soil pH, you can make any necessary adjustments to ensure that your onions will have the best chance of thriving.

If your soil is too acidic, you can use these to raise the pH. on the other hand, if it is too alkaline, you can ammend the soil like this.

Loosen the soil to a depth of 12 inches with the help of a shovel or tiller. This will allow the onion roots to spread out and access more nutrients.

Next, add a good amount of organic matter to the soil. This can be done by adding compost or manure. This will help improve drainage and aeration while also providing essential nutrients for the plants.

Whatever you do, make sure the soil has very good drainage. Good soil drainage is compulsory for a good yield.

How to plant onions:

Planting onions is not difficult, but there are a few things to keep in mind. First, onion plants should be planted 1″ deep. If you plant deeper, the onions may not bulb.

Second, make sure to space the plants about 4-6 inches apart. This will give the plants room to grow and mature. In case you are planning to harvest green onions (scallions), you can leave a smaller space (2”).

Can You Plant a Sprouted Onion?

Yes, you can plant sprouted onions, in fact, many people prefer to do so because it results in an earlier harvest.

When you get an onion from the store, chances are that the onion has been pre-sprouted. This means that the onion has been started in a controlled environment and then transferred to a grocery store.

If you want to plant an onion that you’ve sprouted yourself, you can surely do so.

To plant a sprouted onion, first, peel off the skin of the onion. Then, separate each individual sprout and plant them in soil that is rich in nutrients.

how to plant onions

How to Water onions:

Onions have a shallow root system. This means, that the roots can not get water from the depth of the soil and so take it mostly from the surface and a little beneath. This means while watering, you need to make sure the base of the plant doesn’t become dry.

Overwatering can also be a problem. One of the signs that your plant is getting more water than needed is a tinge of yellow on the leaves. If you find that happening with your plant, reduce the amount of water.

Use Mulch:

Onions cannot compete with most of the weeds. So make sure your soil has minimal or no weeds. You can check organic weed control to know more about how can you remove weeds from your garden.

Using a thick layer of Mulch can be a good idea. You will want to cover them with 2-4 inches of mulch. Mulch will also help keep the soil moist and protect the plant from frosting. There are several types of mulch that you can use, including grass clippings, sawdust, and straw.

Will onions grow through mulch?

The mulch is not the compact portion of the soil it is just the covering of various ingredients on top of the growing soil. the land in many types of soils, for example, with compost, decayed leaves, barks, etc. So ideally they are loose

Mulching is quite common for plants that contain a bulb. When you mulch around the onions it keeps other wild plants and weeds. Onions grow through the bulb and actually prefer mulching.

How To Fertilize Onions Right:

Onions are a cool weather crop and do best when fertilized in the early spring before planting and again in midsummer. A balanced fertilizer such as 10-10-10 is best to feed onions, but avoid using high nitrogen fertilizers which can produce lush foliage at the expense of bulbs.

Nitrogen is necessary for good top growth, but it is the phosphorus and potassium that are essential for good bulb development. Side dress plants with a half cup of fertilizer around each plant about four weeks after planting and again four to six weeks later.

If you are using a granular fertilizer, scatter it evenly on the soil surface and then gently rake it in.

when to harvest onions:

Growing onions is all about getting the bulbs. Once you see the top of the plant turns brown or yellow, your onions are ready to harvest.

Pull or dig the onions out. After that, leave them in the open sun for two days to dry. This will help prevent rotting.

How to harvest onion seeds:

You can harvest onion seeds and use them in the future. Once the onion tops start to turn brown it’s time to harvest the seeds. Simple clip the flowering head off the stalk a few inches below the head and place them in a paper bag.

The heads will eventually turn brown and the seeds will fall out in the bag when they are ready. you can also shake the paper bag vigorously to fasten the process of seed extraction.

How To Store Onions:

tips for growing onions

After drying, the skin of the onion will have a uniform texture. Now it is time to trim the roots and detach the stem from the bulb. Remove any soil that is present on the skin.

These onions are now ready to consume and you can eat your onions right away. You can store your onions in plastic bags and keep them in a dry and well-ventilated space.

We have discussed how to store various vegetables in our earlier article. You can check that article if you want to know about the basics of vegetable storage.

What can you grow after onions?

When it comes to planting after onions, the sky’s the limit. If you’re looking to grow tomatoes, chili peppers, winter squash, swedes, winter cabbage, pumpkins, radishes, or lettuce, there’s a spot in your garden waiting for them.

Onions are biennial plants that complete their life cycle in two years. This means that after they’ve flowered and produced seeds in their first year, the plant will die.

This doesn’t mean you can’t plant anything else in the garden bed where onions were grown; it just means you need to be careful not to plant any other biennials in that bed.

Onion Pests and Diseases

Common pests:

Onion plants are a common garden vegetable. They are susceptible to a variety of pests. Here are some of the common ones:


Mites are very small, spider-like creatures that feed on the plant’s sap. They can cause discoloration and stunted growth.

Leaf miners:

Leaf miners are tiny insects that live inside the leaves and tunnel through the tissue, making it look like there are tunnels or tracks running through the leaf.

Onion maggots:

Onion maggots are tiny white flies that lay eggs in the soil near onion plants. The eggs hatch into larvae that tunnel into the onion bulbs, causing them to rot.

Onions thrips:

Thrips are tiny, thin insects that can cause severe damage to onion plants. They feed on the leaves and flowers and can cause the plant to wilt and die.


Bollworms are caterpillars that feed on the leaves and bulbs of onion plants. They can cause significant damage to the plant if left untreated.

Common Diseases of an Onion plant:

Onion plants are susceptible to a variety of diseases, Followings are some of the most common diseases of onions.


Blight is a fungal disease that can cause the leaves of the onion plant to wilt and die.


Rust is a fungal disease that causes orange or yellow spots on the leaves of the onion plant.


Rot is a bacterial disease that causes the onion plant to rot from the inside out.


Mildew is a fungal disease that causes white patches on the leaves.


Smut causes lesions on the leaves and stem of the plant, and can eventually lead to the death of the plant.


The virus causes stunted growth and yellowing of the leaves in onions.

Mostly there is very little cure for the disease, so it is important to take steps to prevent them from occurring in the first place. One way to do this is to make sure that onions are planted in well-drained soil, and that they are not overcrowded.

If you do notice symptoms of either disease, remove any infected plants immediately and dispose of them properly.

How to grow onions in a pot:

Onions are a great vegetable to grow in a pot. They don’t need a lot of space and they are relatively easy to grow.

In order to grow onions in a pot, you will need a large-mouthed container so you can harvest them easily.

To get a decent yield you should plant several onions in that pot.

Make sure the pot is at least 10 inches deep otherwise they won’t get enough space to grow. You can also use tubs to grow onions.

Make sure the container has drainage holes in the bottom so the water can escape. Fill the pot with soil and plant the onions according to the package directions.

Add 2-3 inches of water each week and make sure the soil is moist but not wet. The onions will be ready to harvest when they are big enough for your liking.

Useful tips for growing onions at home:

Onions are a staple in many kitchens, and they can be grown in your garden very easily. Here are 7 tips to get you started:

  1. Choose the right variety. There are many different types of onions, so choose one that is best suited for your climate and growing conditions.
  2. Plant onion sets in well-drained soil. Onions need soil that drains well so they don’t rot.
  3. Add organic matter to the soil before planting. This will help improve drainage and fertility.
  4. Plant onion sets in early spring, or plant onion seeds directly in the garden in late spring or early summer.
  5. Space onions plants 12-18 inches apart, depending on the variety.
  6. Keep weeds under control to avoid competition for nutrients and moisture.
  7. Mulch around the plants to help retain moisture and suppress weeds.


Growing onions from seeds is not difficult as one might think. By following the tips in this article, you will be well on your way to harvesting your own onion crop in no time.

Onion is a very versatile crop. They are used in so many recipes. We are sure you will enjoy the vegetable much more once you grow them in front of your eyes.

So what are you waiting for? Get out there and start growing!

Have any more questions? Check out FAQs about onion growing. And don’t forget to share this page with your friends and colleagues so they can benefit from these tips, too.

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2 thoughts on “From Seeds to Sprouts: Tips for Growing Onions”

  1. Thanks for onion tips. I grew some from onion sets last summer and they were lovely – much nicer than shop ones.
    I have never grown them from seeds though – maybe I will try. I planted onions sets in raised beds recently to over winter and get early onions this spring but the rain has been so bad I fear they will be waterlogged.


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