L. H. Bailey,
Manual of Gardening (Second Edition…
“ Chervil.—The chervil is grown in two forms,—for the leaves, and for the tuberous roots.The curled chervil is a good addition to the list of garnishing and seasoning vegetables. Sow seeds and cultivate the same as parsley.The tuberous chervil resembles a short carrot or parnsip. It is much esteemed in France and Germany. The tubers have somewhat the flavor of a sweet potato, perhaps a little sweeter. They are perfectly hardy, and, like the parsnip, the better for frosts. The seed may be sown in September or October, as it does not keep well ”
