Salsify will be ready to harvest in late autumn or early winter. I've read that you can use the roots as soon as they are large enough to dig, (whatever that means), but the flavor is greatly improved if the plants are allowed to be exposed to a frost. It can actually be left in the ground and harvested as needed, like carrots and parsnips. As an incentive to try them, salsify is a little higher in protein than parsnips and has only half the calories. Scorzonera is also a good source of vitamin E.
Recommended varieties of salsify include Mammoth Sandwich Island, considered the standard variety and most readily available and French Blue Flowered, a French version similar to Mammoth, put fussier. For Scorzonera, try Russian Giant, an extra long variety from Belgium that's popular in Europe and a reliable grower. You can find seed in most good vegetable catalogs. Some to try are: Seeds Blum, Johnny's Select Seed and Nichol's Garden Nursery.
And when your crop comes in and you're thinking, "Now what do I do with
it?", try one of these recipes. Crispy
Rolls of Salsify with Prosciutto and Parmesan from
Daniel Boulud, Cream
of Salsify and Mushroom Soup or how about Salsify
Pie.