Planting a Sprouting Onion

It's spring and even the veggies in my kitchen know it. I have had potatoes sprout before I can use them up and bags of carrots all fuzzy with roots. This is half a red onion that I forgot in my crisper drawer. Usually, it would just get soft and rotten before I tossed it, but this tenacious onion started growing green shoots.
I planted it in my vegetable garden bed, with my overwintered kale. I just placed it so the bulk of the onion was below the greens, sort of at an angle because it was growing sideways. I covered it with dirt until just the green tops were showing. It is growing fast, I will try to post another picture of its progress.