True. But I have two issues with planting seeds so late in the season.
1. Soil germination temperature is difficult to keep cool enough. Many seeds in any given seed lot may not even sprout until Fall, when temperatures actually do cool back down. This often results in a mixed bag of seedlings, age wise, with (in some cases) some seedlings having only a cotyledon by early November.
2. Summer temperatures are just too hot and humid to acclimate young seedlings successfully without difficulty. It's just plain darn tough on them. Seeds planted around June 1st would be up by July 1st and have a true leaf by July 15th or a little after. The hottest, most humid time of the year. And the last thing you want is botrytis on that first true leaf! It's hard to spray apply copper based fungicide under the leaves of these little ones and besides, they don't like it either.
But as far as winter hardiness of little ones, as long as they have a single well developed true leaf they're ok to go. I have buried pots of them over winter with only one true leaf without a problem.
