The trick with winter carrots is getting them to germinate in August. They don’t want to. We don’t know if it’s the temperature — hot — or the lack of rainfall — but we always water new plantings in summer — or maybe the unrelenting sunlight that burns up small plants in the thread stage, but whatever it is, carrots, as well as every other cool season veg we try to start in late summer, don’t want to come up, and if they come up, they want to die immediately of sunstroke.
But, but, but –! Last summer we broke the rules and started our winter vegs indoors in half-inch soil blocks in the basement (coolest place). Lots of things germinated (not surprising), and, moreover, some of them refrained from dying even when we put them out in the garden. Everyone knows you don’t start tap-root vegs in soil blocks, and these were disadvantaged by the fact that they were allowed to get pretty big before they were put out in beds (the only security we had that they wouldn’t succumb to the blistering summer sun). Nevertheless, grow many of them did. Many are forked, and many, being planted four or five to the soil block, are twisted, but carrots they are, healthy and fat, and they taste heavenly. Maybe they wouldn’t do for a CSA, but for home use nothing better could be desired.