Tips for Growing Onions
Onions are very compelling to grow because you can literally watch them develop their bulbs over the duration of the growing season, while also delighting as you seen them expand and enlarge as harvest approaches.
You can grow onions almost anywhere in North America, with varieties for the cooler and warmer climates having been developed.
Growing onions isn't too difficult, but when you grow different varieties, it can get more complex because different types demand a different length of days to initiate bulbing.
While onions can be grown from seeds, transplants and sets, for home gardeners sets are undoubtedly the most popular because of their ease of handling and use.
As almost everyone knows, onions can be prepared, eaten and used in almost endless combinations, making them one of the most used foods in the kitchen.
Short-Day, Long-Day Onions
There are exceptions, but for most gardeners all they need to know is the majority of onions we grow and eat are either a short-day or a long-day onion.
Short-day onions are for growing in the south and long-day onions for growing in the north.
This is why you need to know which is which, as they aren't adaptable to the two different regions. That's more important if you're ordering sets, although you'll want to be sure if you're buying locally the supplier understands the difference and they're the right onions for the area you live in.
You can many times have problems here because onions sets aren't usually sold under a brand or type, but usually according to color, like yellow, purple or white onion sets.
It's best to ask the supplier if they're short- or long-day onions to get the needed answer.
You can take steps to boost onions if they're not the correct ones, but why mess with all of that when you can just get short-day if you live in the south and long-day if you live in the north.
In the deep south you have no recourse, as the signal to bulb may never happen from long-day onions and you'll end up with nothing other than the equivalent of scallions.
When to Plant Onions
Onions respond well to cool temperatures, so as soon as you're able to prepare the garden for planting you can sow them. In most key onion-growing regions, unless the weather pattern isn't normal, that will come in the latter part of March or the early part of April.
When planting be sure to get them out soon enough or you'll end up with much smaller bulbs, and in some cases, they may not bulb at all.
Evergreen Bunching Onion Seed
How to Plant Onions
If you're planting dry onion sets, plant them about 1" deep and about 2" to 4" between them. Rows should be around a foot to 18" apart.
Onions that are two inches apart should be harvested as green onions so they don't interfere with the bulb growth of those nearby onions.
For green onions, you can plant sets about an inch deep and almost touching one another. This is no problem because green onions are sown to be harvested before crowding one another becomes an issue.
Because larger sets are prone to bolt quicker, they're the best choice to grow green onions, with the smaller sets the best to be used for dry onions.
Onions will grow almost anywhere, but good soil and moisture, along with cooler temperatures will help them in producing much better for you.
Growing Onions From Sets
Onion sets are the easiest and most popular method for growing onions by home gardeners, as they're easy to handle and plant, and they very quickly establish themselves in the plot or row.
Growing onions from sets can limit you because they are offered in only a few varieties. But most home gardeners grow for large onion bulbs or onion greens, so that's not that big of a problem.
Onions are Easy to Grow
What to Look for in Onion Sets
Other than the desired color, other things to look for in sets, depending on whether you're growing green or onions for bulbs, is the size of the set and how firm they are. If they've left dormancy don't buy them.
As mentioned above, if you want to grow dry onions, the smaller sets, defined by the parameter of being about the diameter of a dime or smaller, produce the most robust onions. Smaller sets also tend not to bolt like their larger counterparts.
When searching for onions sets, be aware that if the sets are round in shape, they'll produce the flatter types, while those onion sets with an elongated appearance produce the round onion shapes.
I'm not sure if they produce green onions better, but research shows that gardeners use white onion sets more than any others for them.
One final tip for acquiring onion sets is to do it as quickly as possible when they reach the store, as the heat of the store could quickly bring them out of dormancy.
If you aren't ready to plant them yet, store them in a dark, dry, cool place.
Growing Onions from Transplants
Even though its easy and a good way to grow onions from sets, if you want the type of onions you see in the catalogs, growing them as transplants is the way to go. That's how you produce those big slicing onions consistently.
You will buy transplants if a bundle, which will usually include up to 80 plants in it.
Catalogs also offer onion transplant bundles, but the cost is prohibitive unless you really want a variety you can't get locally. By prohibitive I mean they'll cost about the same as if you bought the onions in a grocery store.
Quality is part of the onion experience, so that may not be that big of a deal, but just be aware of costs when buying from catalogs. They cost anywhere from 3 times to 10 times the cost you would pay locally for onion transplants.
Just like with onion sets, remember to check out if your area does better with short- or long-day onions.
How to Plant Onion Transplants
Onion transplants should be placed in fertile soil in early spring for your area. Plant them about 5" apart, maybe a little less, to give them room to expand into the big bulbs you want. If you plant them too close you'll defeat the purpose because they won't grow as large as you expect or want them to.
Like onion sets, you can space them closer and harvest some as green onions and leave the remaining onions to grow bigger.
Rows for onion transplants should be from a foot up to eighteen inches apart. If you're growing onions in a plot or bed, space them about six inches to eight inches apart. All should be placed about one inch deep, or a little more, in the soil.
Give the transplants an application of starter fertilizer after you plant them.
Caring for Onions
Onions do need to be kept relatively free of weeds because of their shallow root system. That requires them to be cultivated shallowly. This is especially important in the early period when the onions are smaller.
Competing for nutrients may result in you needing to fertilize the onions as they start to grow so they bulb as you expect.
For green onions, a little secret to produce those nice white stems is to hill the onions similar to the way you hill potatoes, except on a much smaller basis of course.
Just pull the soil towards the onions with a hoe when the plant reaches about 4 inches in height. You don't want to wait until it gets too tall or you'll only get a limited amount of that bleached look, instead that long, white stem that looks so attractive.
On the other hand, whatever you do don't hill onions you're growing for bulbs, as it could result in them rotting when they're stored.
Harvesting Green Onions
Green onions can be harvested once they reach about six inches in height. You can leave them in the ground to grow larger, but bear in mind they will become more pungent as they mature.
That's not a problem if you like the stronger taste, and they do cook well if they're too strong for your tastes.
If you want green onions for both uses, just allow some of them you want to use for cooking to continue growing.
Many people throw away the leaves of green onions, but they are in fact edible, and add nice color to a meal presentation. I find they taste pretty good as well.
Harvesting Bulb or Dry Onions
When harvesting bulbs the first thing to do is pull any onions that have flower stalks on them. They're edible and tasty, but they won't store well, so use them in your meals as soon as possible.
How you know when it's time to harvest bulb onions is when the tops fall over and start to have a dry appearance. Just let the process take care of itself naturally and don't try to aid it, as some gardeners are tempted to do.
This is also important because if you prematurely break off an onion top it will stop its growth cycle. That results in smaller bulbs which aren't good for storing.
The best time to pull onions is in the morning. Then you should, unless it's an extremely hot, sunny day, leave them out to dry until the latter part of the afternoon or early evening. To prevent sunburn on hot, clear days, place the onions in a shaded area until they are completely dried. Otherwise just field-dry them.
Once they're dry, and before the night dew comes down, take the onions and place them in a dry, ventilated area where they will fully dry and cure. You can tie or braid the onions by themselves and hang them, hang them in mesh bags, place them in slatted box off the ground or floor, or any method that allows for air circulation. They should be kept like this for about three weeks.
Don't remove the outer skin or scales of the onion as that helps them keep longer.
Tips for Growing Sweet Onions
Harvesting Before Fall Rains
When your onion plants are pretty full and some are starting to fall over, you may receive a fall rain, which will press you to have to make a decision.
Mature onions can rot very quickly when lodged in wet, cold soil. That means you may have to harvest them when a heavy fall rain is forecast, or may appear suddenly.
The decision is whether you want to take a chance on them possibly rotting. or having less to store in the winter. If you pull them while they still have a lot of green on the stems, they won't store nearly as well as when they fall down and are brownish and dry looking.
It is rare that the timing will happen in this way, but it does happen, and if you have sufficient notice and time to do it, you probably will want to harvest them before it rains to salvage the harvest.
That means less onions stored for the winter and more for the table. You can of course take the proper storage measures and have some success with the onions that hadn't went completely dormant yet, but those will struggle to store as long as they would under optimal conditions.
In this case having a storage system where the non-dormant onions are placed in areas where they are identified as needing to be used first is important.
Once the onions are fully dry, cut the stem down to about 1 inch to 2 inches long. Usually that's the area where the stem fell over. Now place the onion bulbs in a dry storage area with air that circulates well.
If you find any bulbs that have green tops, thick necks, are bruised or diseased, don't attempt to store them as they won't last. These, other than the diseased onions, should be used as soon as possible. You will want to give a taste test on the onions with thick necks as they may not have a great flavor; although they could be suitable for cooking.
Onions stored in this manner should last until almost the end of the calender year. You do need to check consistently for those that may start to soften or rot. Those should be removed and thrown away.
Growing Winter Onions
Talk about the ultimate storage strategy, which is to grow onions in the winter with storage being the ground and plant itself.
I am of course referring to what are called Egyptian, tree or walking onions, which are hardy in the majority of places in the United States.
In this case the onions produce sets or little bulbs near the top of the plants. If you don't harvest and replant them, they will eventually fall over and plant themselves. This is where it gets the name "walking" onions, because they can spread like this across an area.
All parts of this onion are edible, with the green on tops to the bulb underneath.
Oh, and don't be afraid of the walking term in the sense of it taking over your garden like a weed. It is easily controlled by simply deadheading the tops so they don't fall over and plant themselves.
Finally, this is a perennial, so plant them in an area that you won't be thinking of using any time soon for something else, or would interfere with your regular garden. They can be eaten and used like any other onion.
Egyptian or Walking Onion
Wow. Talking about these onions sure gets me eager to plant or harvest them to get some great additions to my meals, or store them up for the winter.
We've just barely touched on onions, as there are many speciality types and offshoots like scallions, chives and shallots, which are great additions to the home garden too.
Whether slicing onions or green onions, they are part of many recipes, and can be eaten raw by many who favor the flavor.
Whatever the use, the onion is something we all need to try growing, and if you follow these tips and guidelines, you should be up to your knees in them before you know it.