I live in central Ohio, zone 6a. Last year I harvested my carrots right after Labor Day (first Monday of September) and they were pretty nice. I've been picking them as needed this year, but I'm wondering when I should go ahead and harvest all of them for freezing. They're already mature, but I'd like to let them grow as long as possible before pulling them to maximize the harvest.
When is the best time to pull them?
It depends when you want them. They should last until winter in the ground without bolting. Carrots are normally biennial, and will bolt during season 2. You can harvest them at any time while growing, and can leave them until a hard freeze. They take frost, but not a hard freeze. There is another thing you can try: Put haybales end to end down both sides of the row, and another row to lid it off. Place bales on the ends to seal everything off. This can be done when the first hard freeze is forecast.
This will keep it from freezing, even up to zone three. You can go out and harvest very crisp, sweet carrots all winter, by lifting a bale. They'll even keep up the quality into spring, if you haven't eaten them all. They're far superior to frozen or cellared carrots. You can also use the hay as the next seasons mulch.
When you are going to eat them. Mulch heavily over the row when frost comes to keep the ground from freezing too much, and dig as needed through the winter. Tastiest and best storage. If you have a root cellar (not a modern heated basement) your second-best storage option (or best if you have problems with them being eaten in place in the garden) is in a bucket of damp sand in the root cellar. But digging them up as you need them really is the best. Just leave yourself a marker you can find for when you need to get where you stopped digging the last time after a snowstorm buries it all.
