This post may contain affiliate links. If you use these links to buy something we may earn a commission. Thanks.
You can calculate how many onions to plant to grow any harvest you want.
To do so, you’ll need to decide on the harvest you want!
In the next steps, averages will reveal the right number of onions to plant per person to yield the right amount of onions.
Rather than throwing a random number at you, I’ll help you decide how many onions to grow based on your wants, needs, and limitations.
Storage time is a big consideration for bulb onions. You’ll need to grow more or less of some varieties to have a reasonable shelf-life for a long-lasting store of onions.
A year’s worth of onions looks different between onion types.
For perennial onions, you’ll eat for the greens, you’ll need to plant once, they will spread, and provide green onions every year without the need for replanting.
We grow Welsch and Egyptian Walking onions for fresh and dried green onions year-round.
For bulbs, you’ll need to determine a set number to grow yearly. This set number will be founded on how often and how much you use onions, and the type of onion you grow.
In general, you’ll need 184 onions per person when using one onion daily in meals cooked for two people. Each onion seed that germinates will grow one whole bulb.
The tricky part about choosing how many onions to grow is how many of each onion variety.
Each variety of bulbing onions has more or less of a shelf life. So you’ll need to choose wisely how many of each onion type to grow—to yield the total number of onions you’ll need for the year.
You better not be growing 100% sweet onions if you plan to grow a year’s worth of bulbing onions—you’ll have nothing but rotted compost by the second quarter.
So enjoy your sweet onions early. Grow plenty, but cook them into caramelized onions, and freeze extra for later before your sweet onions go bad in a few (3-4) short months.
How many onions do you use?
This may seem like a simple question, but we need to break it down before we scale up for an accurate answer.
How many onions do you eat in a year?
Tough to answer.
How many onions do you use in a meal?
Easy to answer!
Onions are staple food! You probably use more than you think, if you’re an onion lover like me.
We tend to use one onion per meal which makes food for 2 people. So in the crop calculator I use, I’ll put “0.5” to represent half an onion per person per meal.
The math is pretty simple for onions. But since I use the calculator for everything else, I use it for onions too. Plus, I think it helps to show you visuals rather than just words!
How often do you use onions?
Now we know we use half an onion per person and per onion-containing meal.
How many meals contain onions?
Hard to say.
How many meals a day do you use onions?
- dinner only?
- lunch and dinner?
- dinner and a side dish?
- breakfast too?
How many times per week do you use onions?
We use one onion in nearly every dinner for two. If not at dinner that day, then we used one at lunch. For some dinners, we also make sides that include onions.
Taco Night, for example, has onion in the guacamole, salsa, and fresh ‘pickled’ onions. Plus the rice and sauteed peppers will also have their own onions!
So it’s easy to say we use no less than 7 onions each week and up to 12 in a week.
To represent this thinking, I entered the following:
It then shows that we eat onions 9.5 times on average per week. Since we use 0.5 onions per meal per person, we each eat an average of 4.75, or 5, onions weekly.
How many onions to grow per person?
Now, what timespan do you wish to eat onions for?
- Do you want to grow a year’s worth of onions?
- Do you eat onions for 12 months of the year?
We do! So I put 12 months. Or, you can multiply your weekly onion consumption by the number of weeks, such as 52, to get your answer.
We wondered how many onions we would need for a year’s worth of food and only figured it out after breaking it down like this. The answer is clear and accurate, and not some random guess from a random blog post.
Grow 247 onions per person to provide a true year’s worth of this staple cooking ingredient. Each seed that germinates will form one onion bulb. If you use half a bulb per person, per meal, for two people, 7-12 times per week, you’ll need a total of 494 onions to harvest.
Now, how many sweet onions, versus storage onions, versus red onions shall we grow?
How long will onions, by type, keep in storage?
Over time, you’ll gather the knowledge and experience on how long you are able to keep onions for, using your storage environment and processes.
But in the meantime, we should focus on long-term storage onions, and grow a handful of sweet onions, or however many to quench your thirst for caramelized onions.
Before growing our onions, I wanted to know how long home-grown onions keep in storage by variety.
Since not all onions keep for the same length of time, this is important to know, as you’ll surely have bad luck growing 247 sweet onions per person.
Grow 40-60 onions with a short shelf life, 40-60 medium storage, and 127 long-storage onions per person. You’ll use an average of 20 onions per month. Use sweet onions first for 2-3 months, then your medium-storing onions for the next 2-3 months, and use long-lasting onions until the next harvest.
While sweet onions have a short shelf life, you can still grow extra, even double the amount if you want. Just cook them up and freeze them for later.
You do have several months of time to get short-lived onions used, though.
Sweet onions have more water content and store for up to 3 months on average after curing. At the 3-month mark, they decline with mushy spots and mold growth from the inside out.
The most popular sweet onions are Ailsa Craig, Walla Walla, Vidalia, and Kelsae Sweet Giant. White or Yellow Sweet Spanish are longer-lasting sweet varieties that can keep 3-5 months.
All of these onions will store for about 3 months before they begin to decline at a heavy rate.
Storage onions last a lot longer than sweet varieties. They are lower in water content and sugar, and are a lot more pungent—less desirable for raw eating.
Storage onions keep for 6-12 months, and that’s after harvest and curing time. With proper curing and an appropriate storage environment, you’ll extend the life of your onion harvest.
For this reason, you’re bound to use sweet onions first, and storage onions for the rest of the year.
Since sweet onions last for 1 quarter of a year, you’ll want to grow 1/4 worth of sweet onions, and 3/4 worth of storage onions.
That’s 60 sweet onions and 187 storage onions per person.
The longest-lasting yellow storage onions are Patterson, Yellow Globe, Pontiac, and Copra. Long-lasting red storage onions are Red Bull, Red Zeppelin, and Red Creole.
Medium storage onions include Southport White Globe, White Sweet Spanish, and Stuttgarter.
When choosing the onion varieties to grow pick ones for your climate first. “short day” versus “medium day” versus “long day” onions.
We grow long-day onions.
So our onion plan would look like this:
60 Ailsa Craig, 87 Red Bull, and 100 Patterson onions per person for the right garden harvest.
I hope this helped, please leave a comment and let us know what your onion plan is!
With the best chop-and-drop tools, you'll carry less out into the field after learning about all the options you may (or may not) need. Everyday chop-and-drop tools are small, multi-purpose, and...
The best gifts are useful gifts, so mushroom lovers aren't hard to shop for, and this list offers no shortage of practical presents. I asked hundreds of mushroom lovers and hunters about the best...