|The parsnip (Pastinaca sativa) is a root vegetable closely related to the carrot and parsley. It is a biennial plant usually grown as an annual. Its long tuberous root has cream-colored skin and flesh and can be left in the ground when mature as it becomes sweeter in flavor after winter frosts. In its first growing season, the plant has a rosette of pinnate, mid-green leaves. If unharvested, it produces its flowering stem, topped by an umbel of small yellow flowers, in its second growing season. By this time the stem is woody and the tuber inedible. The seeds are pale brown, flat and winged.
The wild parsnip from which the modern cultivated varieties were derived is a plant of dry rough grassland and waste places, particularly on chalk and limestone soils. Parsnips are biennials but are normally grown as annuals. Sandy and loamy soils are preferable instead of silt, clay, and stony ground; the latter produces short, forked roots.. Parsnip seed significantly deteriorates in viability if stored for long. Seeds are usually planted in early spring, as soon as the ground can be worked to a fine tilth, in the position where the plants are to grow. The growing plants are thinned and kept weed-free. Harvesting begins in late fall after the first frost, and continues through winter. The rows can be covered with straw to enable the crop to be lifted during frosty weather. Low soil temperatures cause some of the starches stored in the roots to be converted into sugars, giving them a sweeter taste. (Source: Wikipedia)