Growing Onions Everything you Need to Know.

Are you looking to grow onions in your garden? I will show you everything you need to know to grow onions! Seed onions, onion starts, long day, short day, so many things I had not known till I really researched it.

Why Do You Want to Grow Onions

When deciding to grow onions, you should first think of why you want to. I am growing onions to have enough onions to get me hopefully through the winter, so I plant storage onions. I also determine how many onions I use per week and what type, red, white, yellow. Having onions during the summer is taken into consideration also. Now if you just want onions and have no desire to store a large amount, you need to figure out how many you would like to have. The first year I planted onions I planted over 100 and they were not storage onions, I never got through them all before they started to go bad. So you need to know this to grow onions for your needs.

Types of Onions

Red: Red onions are sweet onions, they are what we use mainly in salads, on top of pizzas, sandwiches, and burgers. They usually do not burn your eyes and make you look like you watched a very sad movie.
Yellow: These are your all-purpose onion. They sometimes are called brown onions, they have very papery skin. They are pretty strong till cooked and then they soften up and get sweeter.
White: White onions can be a substitute for yellow or red. Good eaten raw, they are used raw on hamburgers, in salsas.
Sweet Onions: These you probably recognize as your Vidalias or Walla Walla onions. Great for caramelized onions and onion soups.

Know Which Onion to Grow for Your Area.

This was very interesting to me and probably why I didn’t have the greatest success with growing my onions. I had no idea that onions have different day lengths. So when you are getting ready to get onion sets or seeds, you must pick the type that is right for your growing area. To get the best onion, you need to figure out where you are, below, above, or right on the 35th parallel of the map. This is key to learning everything you need to know about how to grow onions.

Who knew Geography was involved in growing onions!

Short Day: Below the 35th Parallel. These onions need a mild climate, zone 7 or above. They need 10-12 hours of sunlight. These are usually planted in fall and harvested in spring. Short days are grown in the south. They can be grown in the north, but your onions won’t get as large. If planted in spring in the northern climate average days to mature are 75. Average 110 days to mature in the south.
Long Day: Above the 35th Parallel. These are grown more in the northern regions, Zone 6 and colder. 12-14 days of sunlight are needed for these onions. Long day store well, and take about 90 to 100 days to mature. Plant late fall or early spring. Late fall you will harvest in the spring. Great for two plantings in your garden!
Intermediate Day: This is the middle of the United States. I am in Colorado, so this is what I would plant. These need 12-14 days of sunlight. Great for zone 5-6. Mature in 110 days, can be planted early spring or late fall for a spring crop. Another great way to get a second planting in.

Getting Onion Starts or Seed to Grow

Onion Sets

Most new gardeners and some seasoned usually go with onion sets. You can find onion sets at your local garden stores, online, nurseries, and big-box stores in the garden department. There is nothing wrong with starting onions from sets. But you are limited on the varieties that you can grow.

Here is a link to Gurneys where you can buy online. ( I am not affiliated with Gurneys) and get a look at different varieties. Online you will find much more seed set varieties than at a box store.

Onion Seeds

Onion seeds are the way I like to go. You get so much more for your money, and also you can pick from so many varieties. Seed start these early and you can put them into the ground when your soil and temps are ready. Or plant them directly in the ground. I like having control of what I plant, so seed starting is the way I like to do things. Waiting around to see if they are going to germinate is way too painful for an impatient person.

Starting Seeds Indoors

Starting seeds for onions is so easy! They are very small and you can heavily scatter them in your starting tray. Once they are about 3-5 inches tall you can carefully separate them and put them in your garden. Growing onions this way is how I do it now!

If you would like to know where to find onion seeds to grow, here is my favorite place to shop. Johnny’s Seeds (not affiliated with them)

I use these trays to start… https://ahttps://amzn.to/3pcgyHv

Planting your Onions

Ideally 4-6 inches apart for onion spacing in your garden will get you a much larger onion. If you plant closer because of space issues, they will still grow, but produce a much smaller bulb. Make sure to leave a walkway between them so you’re not stepping on them.

When planting onion sets, place green stem up and cover bulb completely with soil.

Onions started from seeds, but plant them like you would any other transplant.

Cover both sets and seed starts up to the neck of the plant, but do not bury the neck.

Plant Care For Growing Onions

Everything you need to know about how to grow onions wouldn’t be complete without knowing how to care for them.

Sun: Onions need full sun to grow. That is why above you should follow the right onion for your area.
Water: Onions need 1 inch of water a week. Depending on how wet or dry your climate is. The more you water, the sweeter your onions will be. If they become too dry, they will bolt and go to seed.
Well Drained Soil: Well-drained, loose soil. If you are planting into heavy rocky soil, the bulbs will have a hard time growing. Add compost to loosen it up.
Fertile Soil: Onions are heavy feeders because they are growing underground. You can add aged compost to your row, on the bottom of your row as planting to help boost that. Every few weeks fertilize with nitrogen. Once the bulbs start to push out of the ground stop fertilizing.

When to Harvest

There are several times when you can harvest your onions. Midsummer you can check the bulb size and if it is large enough, global in size, you can pick that for immediate use. Late summer or early fall you will start to see your onion tops start to flop over, this is a sign your onions have stopped growing. The flop will start at the base of the onion. They will not grow any larger after this point. Harvest your onions soon after you see this.

Start to Seed: If your onion sends up a flower, it has stopped growing and you should pull that onion.

Start to Seed: If your onion sends up a flower, it has stopped growing and you should pull that onion.
At the base of the onion when the bulb starts pushing from the ground and the top is starting to droop, brush soil away from the bulb. This will help it to dry out and not rot as quickly.

How to Store Your Onions

Once you have pulled your onions from the ground, you will want to dry them out. If you want to leave them right on the ground to dry, you can, I put them in my greenhouse. A garage or barn would work fine also. Critters might haul them off while on the ground, or they can be rained on.

If you wish to braid your onions once dry, you leave the stems, if you wish to store them in a box, cut the stem off and leave them about 2 inches.

Onions should be stored in a cool dry place. A well venalated area is ideal. Do not store in the fridge because they will rot.

Do not store with other fruits or potatoes, they will ruin the flavor and cause them to rot!

Now you know everything about how to grow onions!