The view in early June shows onions holding their own between closely-spaced tomatoes and broccoli (left). However, even at this point, the lower parts of the onion stalks spend most of the day in shade. The stalks are the leaves, and they obviously require full sun all day for best production. (Ignore the onions on the right; they are last season’s victims of the Lost Onions method of kitchen gardening.)
My small kitchen garden is a laboratory that provides evidence each year supporting well-accepted theories of kitchen gardening. It also suggests that many alleged “best practices” are, at best, pretty good practices. This season, my success with crowding tomatoes, cabbage, broccoli, and cauliflower reinforced my growing belief in cramming together vegetable plants to maximize your harvest. Eventually, I suppose I’ll have to think up a cutesy name for this approach so it can take its place next to “square foot gardening,” “lasagna gardening,” “straw-bale gardening,” “vertical gardening,” and “no-dig gardening,” among others.
The Lost Onion Gardening Method
Last season, I planted several rows of tomatoes in which I left only 12 inches from one plant to the next. Until late blight struck, the plants thrived. So, in the interest of growing more produce in the same space, this season I went a step further: I set plants a foot apart within their rows. I also laid out rows very close together.
Here’s a map of my small kitchen garden’s main bed in 2010. I added details only in the section I’ve described in the main article: Tomatoes, onions, cabbage, broccoli, and cauliflower (labeled as broccoli). The grid represents one-foot squares, with the planting bed being 14’ deep and 28’ long. When you plant this tightly, you don’t walk in your vegetable garden, you wade in it.
I left just 18 inches from one row of tomatoes to another. When that looked “airy” I planted a second pair of rows with only a one-foot gap. My rationale for putting two rows of tomato plants just one foot apart was that I’d be able to reach and manage both rows of plants from one side.
18 inches from one of the tomato rows, I planted a double row of onion sets: white and purple. 18 inches from there, I planted a zig-zag row of broccoli plants, making the broccoli row itself very crowded. The line drawing shows this section of my small kitchen garden with tomatoes on the right, then onions (with cabbage at the bottom), and then broccoli and cauliflower.
I was very happy with this layout with one exception: I lost my onions.
How my Garden Grew
After several hard frosts, I peeled back the dried up tomato plants and ripped out small broccoli trees. There, right where I’d planted sets in the spring, were young onion sprouts. A few onions are in good enough shape that I can use the bulbs. The others’ stalks will substitute as spring onions in my Chinese stir fry dishes.
Technically, I didn’t so much lose my onions as I lost access to them. The tomatoes grew like champs, eventually extending four feet beyond the tops of their 7 foot supports. The broccoli also outgrew the onions; by season’s end one broccoli plant was eight feet tall!
The onions? They kept pace with the tomatoes and broccoli for a while, but sadly, onions grow to about 20 inches. So, the season wasn’t far along before the onions were in complete shade.
Consider the onion: They have tall, slender, spiky leaves that seem well-adapted for survival in very sunny climates. They have none of those thin, flimsy leaves typical of annuals that can’t survive extreme summer heat.
Heavily shaded, only a few of the onions produced flowers. But by the time the tops should have matured and started falling over under their own weight, the tomato and broccoli plants had formed a canopy over them; I could barely wiggle between the plants to do maintenance, and no way was I able to bend down to the onions without displacing tomatoes or broccoli. I’d lost my onions.
Mid autumn is a tad late in the year to pull your first onions but these are my first. There may yet be another dozen golf-ball-sized wonders ready to harvest from my small kitchen garden.
In early November, I dismantled the tomato trellises, pulled the spent plants, and ripped out the broccoli trees. As I pulled back the weeds, lo-and-behold: there were young onion tops! These were a large onion variety, but the biggest ones in my garden are the size of golf balls. In many cases, the onion bulbs are too ratty to eat. However, the tops are tender enough to use as spring onions.
So, despite the abuse I’ve given these plants, they have forgiven me and provided some flavor to my life and my cooking. They have also taught me that onions will not tolerate crowding if it covers them in shade. When I plant onion sets next spring, they will have the front row of southern exposure… or there will be a generous three foot gap on each side of the onion bed to assure a sunny disposition.