This plant is grown for its large, edible root. Pastinaca sativa, which was known to the ancient Romans and Greeks, is commonly known as the Parsnip. This tasty taproot may grow 32 inches in diameter and 10 to 18 inches in length. Long-stemmed, divided, dark green leaves arise from the root, growing 3 feet high or more. These vigorous plants provide only a moderate amount of food for the space that they take up.

To develop large, smooth roots, these plants need to grow in soil that is deep, moderately fertile and loamy, but free from any stones and chunks of compost that can disfigure the roots. In soil that is heavy, dig 2-foot deep holes with posthole diggers and fill them with the soil mixture described above. Each hole will support two plants. They should be thinned to 12 inches apart when very little for large roots. Don’t let the soil go dry for long periods, because the roots may split when a heavy rain comes. Parsnips need 4 months to grow and taste better after cool weather, which converts some of the starch to sugar. In the North before the ground freezes hard, bank up the plants with straw to keep the soil soft. In the South, dig roots up as needed and store a few at a time in plastic bags in the refrigerator to make the roots sweeter.

Grow Parsnips from seeds, which are large, flat and notoriously short-lived. Direct-seed in early spring in northern regions and central states. In areas with mild winters, plant seeds in late summer to mature during the winter. In hot soil, aid the seeds in germination by flooding a furrow with water, let it soak in, and repeat. Set the seeds an inch apart and cover with c -inch of sand. Place a board over the furrow. Mist every few days and replace the board. The seeds may take 3 to 4 weeks to sprout. They should be thinned a foot apart.

Pastinaca sativa. Hollow Crown, Harris Model, All-America.