An Ode

Onions, how do I plant thee? Let me count the ways. I plant thee just once for years of harvests if thou are the perennial potato or Egyptian onion. If thou are the pungent, but long-keeping, American-type onion, I sow thy seeds in the garden in the spring. And if I were to choose like most gardeners, I would plant thee in spring as those small bulbs called onion “sets.” (Apologies to E.B. Browning)

New Old Ways with Onions

Early March brings us to yet another way of growing onions: sowing the seeds indoors in midwinter. This was the “New Onion Culture” of a hundred and fifty years ago, and, according to a writer of the day, “by it the American grower is enabled to produce bulbs in every way the equal of those large sweet onions which are imported from Spain and other foreign countries.” This is the way to grow the so-called European-type onions.

Walking onions

Walking onions

What’s wrong with growing perennial onions, American-type onions, and onion sets? Neither perennial nor American-type onions have the sweet flavor of the famous Vidalia onion, a European type. And onions for sets are generally limited only to the two varieties marketed, Stuttgart and Ebenezer, whose important quality is that they make good sets. A few seeds companies sell sets of a better variety, Forum. In addition to variety, quality of sets is important: too large and they become useless as they send up seedstalks.

The New Onion Culture is a way to grow the large, sweet, mild European onions, such as Sweet Spanish.

The “Method” is as follows: About 10 weeks before the last hard freeze, fill a seed flat with potting soil and use a plant marker to make furrows 1/2-inch deep and one inch apart. Drop about seven seeds per inch into the furrows and then cover the seeds with soil. Fresh seed, less than a year old is best. Water the flat, then keep it moist and warm and covered with of pane of glass. The onions should sprout in a week or two.

Once the onions sprout, remove the plastic or glass and give the seedlings plenty of light. Put the flat either within a few inches of fluorescent lights, on a very sunny windowsill, or in a greenhouse. Each time the seedlings grow to six inches height, clip them back to four inches. The trimmings, incidentally, are very tasty. This indoor stage of plant growing can be bypassed by purchasing onion transplants (not sets), which are sold mail-order in bundles of twenty-five.

Get ready for transplanting a few weeks before the predicted last freeze date. Choose a garden spot where the soil is weed-free, well-drained, and bathed in sunlight. Onions demand high fertility; my plants go into a bed that was dressed with an inch depth of compost last fall. Give the onion seedlings their final haircut, tease their roots apart, then set them in a furrow, or individual holes dibbled with a 3/4-inch dowel. Plant seedlings two to four inches apart, two inches if you want small bulbs, four inches if you want big bulbs. 
Onion growing cycle
This may sound like a lot of trouble to grow onions. But for me, midwinter onion sowing inaugurates the new gardening season. The onion is an apt inaugural candidate; it responds to “high culture” starting with careful sowing in fertile soil and moving on to good weed control, timely watering, and, after harvest, correct curing after harvest. 

Besides providing this midwinter ritual, onions raised according to the New Onion Culture do have superb flavor.

(The above was adapted from my book A Northeast Gardener’s Year.)

And Still Newer Ways

And now for the “Newer Onion Culture”: American-type onions have the advantage of being better for long-term storage, and newer varieties also have very good flavor. My current favorites are Copra, Patterson, and New York Early. They also are “long day” onions, setting bulbs when the sun shines for 15 to 16 hours daily. “Short day” varieties, which are adapted to the South, would bulb up too soon around here, producing puny bulbs.

There’s more to the “Newer Onion Culture.” A couple of years ago, a local farmer, Jay, of Four Winds Farm, told me he gets good results by just planting seeds in furrows right out in the field.

And even more. Instead of planting 7 seeds per inch indoors in furrows in early March, sow them in flats of plastic “cells” with 4 seeds per cell (each cell is about an inch square). Onions seedlings in cellsWhen transplanting out in the garden, plant each cell with its seedlings intact, spacing them further apart than you would with individual transplants so their roots get adequate water and nutrition. As vegetable growing maven Eliot Coleman wrote in Four-Season Harvest, “the onions growing together push each other aside gently.”

Back to my original query: “Onions, how do I plant thee.” Many ways. I’ll do four out of the six ways this season.
Onion braid


The Onion Cycle Begins Again

Early February, February 6th to be exact, was the official opening of my 2017 gardening season. No fireworks, waving flags, or other fanfare marked this opening. Just the whoosh of my trowel scooping potting soil into a seed flat, and then the hushed rattle of seeds in their paper packets. And the grand opening was not for a flamboyant, who-can-reap-the-earliest-meal of a vegetable like peas or tomatoes.

No, the grand opening for the season is rather sedate: I sowed onion seeds in mini-furrows in a seed flat. Why onions? In addition to the fact that I love the flavor of onions raw and cooked, onions need a long growing season. The summer growing season is cut short because the plants stop growing new leaves to put their energy into swelling up their bulbs when daylengths grow sufficiently long, 14 hours long, to be exact. Around here, that happens sometime in May. The more leaves the plants make before then, the bigger the bulbs. Hence my early planting.Sowing onions indoors

So I poured about a 3-inch depth of potting soil into an 18 by 24 inch plastic tub in which I had drilled drainage holes, and then made seven parallel furrows in the soil into which I dropped onion seeds. This year I’m growing New York Early, Patterson, and Ailsa Craig. (I also sowed leeks in one of the furrows.) After closing up the furrows, I watered, covered the tub with a pane of glass, and put the tub on a heating mat set at 75 to 80° F.

Done. The season has begun.


Other Beginnings

There are so many ways to grow onions. Let me count the ways, some other ways.

1, and easiest, is to just plant onion sets, those mini-onions you can buy to plant as soon as the ground outside warms and dries up a bit. One downside to sets is that the variety selection is very limited. Not only limited, but also restricted to so-called “American-type” varieties, which keep very well but are very pungent and not very sweet. Onion sets that are too large — larger than a dime — tend to go to seed. Plants going to seed look very pretty but don’t make bulbs for eating.

Number 2 method overcomes one of the limitations of method number 1: Purchase onion plants, which are growing plants, with leaves. The sweet “European-types” — Ailsa Craig, Sweet Spanish, and Granex, for example — are available in this form. The plants are grown in fields in the South, and there’s the potential to bring a disease into the garden on these plants. Also, “organic” onion plants might be hard to find.

Setting out onion transplants

Setting out onion transplants

Method number 3 is the most involved. (I’ve never tried it.) Grow your own onion sets. The trick is to sow the seeds outdoors densely enough so that they bulb up while still small — dime size. Once bulbs mature, their harvested to store for winter, and then planted in spring just like the sets in Method 1.

Method number 4 is fairly easy, and that is to sow seeds of the Evergreen variety onions right in the ground in spring. This variety never forms bulbs but makes tasty green onions, or scallions. It’s also perennial, so any scallions left in the ground will multiply year after year. The downside here is that you don’t get onions for winter. I grow these every year and do get them for winter use also, in my greenhouse. 

Method number 5 is easiest of all. Grow Egyptian, or Walking, onions. This is another perennial onion. It “walks” by forming bulblets on top of some stalks. The weight of the bulblets pulls down the stalk, and when the bulblets touch ground, they root to make new plants. The new plants eventually send up bulblet-topped stalks which likewise bend to the ground, etc., etc., walking the plants around. To me, Egyptian onions are all hotness with little other flavor. I no longer grow them.

Walking onions

Walking onions

I learned of method number 5 from Jay at Four Winds Farm. Simple enough. Just sow the seeds outdoors as soon as the ground is warm enough and dry enough for a nice seedbed. A nice seedbed is key here, because onions compete very poorly with weeds and the goal is to get the seeds to germinate as fast as possible. I tried this last year and the bulbs ended up pretty much the same size as those from the plants I sowed last February and then transplanted into the garden in April. So I get a wide choice of varieties without having to start the seeds in February. Thanks Jay. (I’m growing transplants and direct seeding this year, just to make sure.)

My Pea Planting Will Not Be On St. Pat’s Day!

My early February onion-sowing date isn’t some magical date. My greenhouse is only minimally heated, making for very slow growth early in the season. Growth picks up as sunlight grows more intense and further warms the greenhouse. A week or more difference in sowing date early in the season doesn’t translate into that much difference in growth near harvest time.

The same goes for pea-planting, which is attended by more fanfare than onion planting. Many gardeners rush to get their pea seeds planted by St. Patrick’s day, but planting a week later doesn’t delay that harvest by a week. Perhaps by a couple of days or by a few hours, depending on the season. And anyway, St. Patrick’s day might be the traditional date for planting peas in Ireland, but it would be way too early in Maine and way too late in Georgia. I plant peas here in Zone 5 on April 1st, give or take a few days.

In my book Weedless Gardening, I have a chart that shows what and when to plant, whether as seeds, indoors or out, or as transplants, for all regions. All you have to do is plug in your average date for the last killing frost of spring and the first killing frost of autumn. This date is available from your local Cooperative Extension Office. 


 Onions & More, Late But They’ll Be Fine

   I missed my deadline by four days, sowing onion seeds on February 5th rather than the planned February 1st. That date isn’t fixed in stone but the important thing is to plant onions early.
    Onions are photoperiod sensitive, that is, they respond to daylength (actually, night length, but researchers originally thought the response was to light rather than darkness, so the phrase “daylength sensitive” stuck). Once days get long enough, sometime in June, leaf formation comes screeching to a halt and the plants put their energies into making bulbs. The more leaves before that begins, the bigger the bulbs.
    Plants from seeds sown outdoors — towards the end of March — won’t have as many leaves as plants given a jump start indoors. I like big bulbs; hence the early February sowing.

Fresh Seeds & Mini-furrows in a Plastic Tub

    First step on my way to onion-dom is to get fresh seeds. Onion seeds are relatively short lived and I want to give the plants plenty of time to grow. I don’t risk delays from poor germination and replanting of old seed.Onion seeds being sown in mini-furrows in pan of potting soil.
    Seeds get sown in a miniature “field:” A plastic tub 18 inches by 12 inches, with drainage holes drilled in its bottom and filled 4 inches deep with potting soil. Some weed seeds are unavoidably lurking in the garden soil and compost in my homemade potting mix, so I top the potting mix with a one inch depth of a weed free, 1:1 mix of peat moss and perlite.
    The edge of a board pressed into the firmed soil mix in the tub makes furrows, 6 of them equally spaced and about 1/2 inch deep within the tub. Into each furrow go onion seeds, sprinkled at the rate of about 7 seeds per inch. Once the furrows are closed in over the seeds, I water thoroughly and, to avoid washing away seeds, gently.
    Covered with a clear pane of glass and warmed to 70 to 75° F, the seeds should appear as grassy sprouts above the soil mix within a couple of weeks. From then on, my goal is to keep the plants happy with abundant light and water as needed. They get a haircut, their leaves snipped down to 4 inches, whenever they get too floppy. The compost and alfalfa meal in the potting mix should provide sufficient nourishment to the seedlings until they are ready for the great outdoors. That deadline is April 15th, weather permitting.

Other Cool Temperature Seeds Join the Party

    Onions won’t be alone on the seedling bench in the greenhouse. I’m also now sowing seeds of celery, celeriac, and leek. All, like onion, need a long period of growth before they’re ready for outdoors.

Onion seedlings, up and growing.

Onion seedlings, up and growing.

   These seeds get sown in furrows in small seed flats from which the seedlings, once they have two leaves, are gingerly lifted and cozied into waiting holes poked into the potting mix filling seed trays with individual cells. Little growing space is needed because a single seed flat can be home to a few kinds of seeds and the celled trays in which the seedlings grow until planted outdoors can house about two dozen plants in a square foot.
    I’m sowing lettuce in a similar manner. In contrast to celery and company, lettuce grows quickly. It’s needed to fill in gaps opened up from winter harvests of kale, lettuce, mâche, claytonia, celery, and parsley in the greenhouse, and should be ready to eat in April.

Nature & Nurture & the Spiciness of Onions

    Last year’s onions were abundant, large, sweet, and juicy. Anticipating their not keeping well, we ate them quickly, pulling the last ones from their hanging braid in the basement sometime in November. These were so-called European-type onions, varieties such as Ailsa Craig and Sweet Spanish.
    Next year we should have fresh onions for soups and stews on into winter because I’m growing some American-types, New York Early and Copra. American-type onions are actually sweeter than European-type onions, but their sweetness is masked by their increased pungency. That pungency comes from sulfur compounds, which are vaporized during cooking. Those sulfur compounds are also what help these onions keep longer.

Stored onions, in basement

Stored onions, in basement

    Soil enters the picture when it comes to onion flavor and storability. Sulfur is an essential plant nutrient and the more sulfur in the soil, within limits, the more sulfur in the onions. Sulfur is a key component of organic matter, so my compost-rich soil (with a whopping 15% organic matter) should have plenty of sulfur.
    Still, I’m thinking about spreading sulfur, the same pelletized sulfur I use to maintain soil acidity beneath my blueberry bushes, on half my onion beds to see if flavor or storagability are noticeably affected.