What is the ideal onion spacing/layout?

Question

I purchased some onions to plant in a small planter on my apartment balcony. The planter also contains some lettuces/greens, parsley, basil, and sage. The onions came in a little box as nursery plants do, sprouted with long green stems, with perhaps 15 onion plants packed in very tightly, one next to the other. So far, I have transferred the onions from the little box directly into my planter as-is, but I feel this might not be right and wanted to get some advice.

My hope is to continuously harvest the greens of the onions, for use in salad, eggs, whatever, and occasionally harvest young onions when I want a bit more kick. If a few make it all the way through to mature onions, great.

What would be the best way to lay out these onions? Should I leave them in a clump, separate them out a little, spread them through the planter as singletons?

Answer 1

You don't mention what variety of onion you have, but for how you're planning to use them, I'd recommend fairly close spacing -- perhaps 1" apart.

Normally I plant onions (for mature/bulb harvesting) at about 4" apart in rows 6" apart. This gives them plenty of space so the bulbs are competing with each other.

If you've already transplanted them, you may not want to transplant them again -- too much disturbance will negatively affect the plants. You can achieve the final spacing by thinning: when you want a small onion, carefully pull out a plant that is too close to its neighbors.

I might also suggest planting seeds instead of plants. Something like crystal wax white onion is good for baby onions, and since you'd have a whole packet of seed, you could plant the seed thickly for cutting leaves for flavoring. (If you choose to go this route, remember that onion seed must be fresh -- year-old seed will not germinate well; don't buy last year's seed from the discount rack.)

Another possibility would be chives -- a very hardy perennial in the onion family that you can snip for flavoring whenever you want.