Hamburg Root Parsley Seeds Heirloom Vegetable. For over 400 years, the slender 15 cm (6″) parsnip-like roots with their delicate parsley taste have been used for flavouring soups and stews. This variety stores very well through the winter. A great dual purpose plant as the coarse leaves contribute a parsley flavour and can be used as a garnish. Soaking seeds in water over-night improves germination. Parsley is widely used as a pest control plant in gardens as it attracts beneficial insects.