I planted parsnips this year. Everything in the universe says “wait until after the first frost” to harvest. Okay: HOW LONG AFTER? Nobody will tell me! It says that this is what converts the starches to sugars, which I assume isn’t instantaneous. Some things say “after a few frosts.” Three days? Three weeks?
Thank you both: this is precisely what I needed & couldn’t find. I’m in Vancouver, so the soil won’t freeze like that: and I should have homemade parsnips by American Thanksgiving (if I start at the 2-week point).
Or dig them next spring. It needs to be early in the spring, though; once the tops start growing again, they pull nutrients out of the roots, and the roots will be increasingly less good to eat as the tops gain size.