For the container count, May 1.

Some of us just loosely use the term for stuff we start with the method all year. I'm one of those. Differentiating from seeds I start under lights.

In summer, I do it much the same: milk jug, soil, seeds. I just use a few more vent holes and keep the jug in more shade.

Karen

I'm one who wouldn't describe I'm winter sowing in Spring, or Summer or Fall. But as Karen says, you can certainly sow using the same method you would use for WS, and use that term to shorten the explanation if it pleases you - up to you.

I sow using the winter sowing method up until July or so. I think the agreed cut off for the container count is indeed May 1.

When I read the title of this thread, my immediate response was, "Never!" I also use the term to describe a method of germination rather than the season.

Martha