Adventures of a Transplanted Gardener

Onion sets are up to 1/2" across.  Oh the promises implied on their package.  Photo by Stibolt
Onion sets & their packaging.

The skinny on onions
by Ginny Stibolt

I bought a bag of 80 onion sets (little bulbs up to 3/4" across) at a big box store last fall. For $1.49 I figured it was a good bet. I hadn't done my homework and didn't know what to look for. In October I planted two rows for green onions, where the sets were spaced less than an inch apart and 2 inches deep.  Then I planted one row for table onions where the sets were spaced 3 inches apart and just below the surface.

These instructions, provided on the package, worked well. For months, I picked the outside leaves of the green onion rows to use in salads and cooking. At the end of April, I started pulling up the green onions, one-by-one as needed. I finally got to the table onion row in the middle of June and continued to pull onions one-by-one as needed. I hadn't harvested any of their leaves, because they needed all their sugar produced by photosynthesis to build their bulbs. Most of the sets in this row did produce two to three-inch bulbs, but a few did not. The leaves are more pungent this late in the season and some of the leaves have now completely withered. This is when you're supposed to pull out the onions, braid what's left of their leaves, and hang them on a rafter to dry out. I don't have many left by now, so I'll continue to work my way through the rest of the row and plan better for next year. There was a lot I didn't know.


We planted onion set at the same time we planted lettuce and the other winter crops.  Photo by Stibolt.

Sad-looking rows of onions at the end of July.

Long-day and short-day onions 

The bulbing onions (Allium cepa) fit into three categories: 

1) Short-day: These varieties are recommended for climates that are hotter year round, like here in Florida. They will develop bulbs earlier in the year with only 10-12 hours of daylight.

2)Intermediate-day (or day-neutral): These varieties that need 12 to 14 hours of daylight to start producing a bulb. 

3) Long-day: These varieties require 14-16 hours of daylight to form onion bulbs. These are good for more northerly areas where the summer days are much longer and where the bulbs can't be left in the ground over the winter.

When it gets hot (like now), any of these varieties will stop growing--if I'd left mine in the ground, they'd start to grow again in the fall and produce a flower. I still have the label from my onions, so I was curious what kind I'd lucked into.  There's no indication: The label says, "Onion Bulbs (Yellow)". The fine print on the back says they came from Arcadia, FL.  So that was hopeful--I've learned that bulbs from Holland or Holland, MI may not do well here.  Upon doing some more research I found that onion sets are produced only for short-day onions.  So by dumb luck, I planted the right type of bulb and the positive results prove that out. This fall, I plan to be better organized about my onions and will plant onions sequentially once a month or so during the winter so that our harvest might be a little more spread out.  

Three onions at the end of the season--the end of July. Photo by Stibolt.

Three 2-inch onion bulbs and what's left of their leaves.

Variety is the spice of life

Onions used to be part of the lily family, but most botanists now place them in their own family, Alliaceae.  Onions are not known in the wild, only in cultivation. They were probably developed from a wild ancestor that grew in western Asia. Onion seeds have been found in Egyptian tombs and the onion may have been one of the first farmed vegetables.

Today there are hundreds of onion cultivars, differing in day-length requirement, skin color (white, brown, yellow, red, or purple), size, shape (globe-shaped, flattened, or spindle-shaped), pungency and sweetness. The chemical characteristics of the soil determine much of the pungency and sweetness of the crop. Some short-day cultivars are Excel, Yellow Bermuda, Granex, and Texas Grano, White Granex, and Tropicana Red.

Vidalia onions are sweet, non-pungent short-day onions, usually Granex or Texas Grano that are grown in four counties near the town of Vidalia, GA. Onion farmers there have purchased the exclusive right to use that name. Our onions grown in Florida can be just as sweet.

Bunching onions

Bunching onions (A. fistulosum) are non-bulbaceous perennials that you can keep going with that mathematical oxymoron--multiply by dividing. When you need some onions, dig up a bunch, but leave some in the ground, so new bunches can form. Plant them two or three inches deep if you want the stems to be white. Spring onions or green onions, immature bulbing onions, are often used in place of the true bunching onions. This how I used my two rows of green onions and I'll probably do that again, but I'm going to try some true bunching onions next year, too.  I'll let you know how they do.

Now that the heat of summer is upon us, it is the time for planning your cool weather crops. Can't you just imagine it--you'll be able to work in your garden after 8am and not have sweat dripping from the end of your nose. I can hardly wait.

Ginny Stibolt is a life-long gardener, a botanist, a naturalist, and a garden writer. You may contact her or read more of her articles posted on her website:

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Adventures of a Transplanted Gardener