Heirloom. Long, smooth, tender and sugary roots can grow up to 12" long and be up to 3" wide at the shoulder. Be very patient with germination – it can take up to 3 weeks for the seed to sprout. Also do not be in a hurry to harvest your parsnips in the fall. Roots require exposure to frosty weather to develop full flavour; the longer you wait into November and December, the better the flavour gets.