(For details on growing many other vegetables and fruits, visit our Crop at a Glance collection page.)
The deeply worked soils in permanent beds make great spots for growing parsnips (Pastinaca sativa). Parsnips are related to carrots, but they grow much more vigorous tops and take longer to mature.
A good source of vitamin C and several important minerals, parsnips are a snap to grow in cool climates and as a fall crop where summers are hot. Parsnips need loose, fertile soil that is free of stones and hard clods of compacted soil, with a pH between 6.0 and 7.0. Frequent watering may be needed to keep the soil constantly moist.
All parsnip varieties take a long time to mature, with hybrids such ‘Gladiator’ and ‘Javelin’ maturing about as 110 days after sowing. Compare this with 120 days for open-pollinated varieties such as ‘Cobham Improved,’ ‘Andover’ and ‘Harris Model.’
Try growing a few different varieties, because they may differ slightly in how well they grow in your site and soil.
How to Plant Parsnips
Parsnip seeds quickly lose viability after their first year, so buy fresh seed or grow your own seed crop at least every other year.
Where summers are short and mild, plant parsnips in late spring, a week or two after the last frost has passed. In other areas it is often best to delay planting until early summer, or about four months before your first fall frost date.
One week before planting parsnips, place parsnip seeds on a wet paper towel and enclose it in an airtight container. After five days at room temperature, look for the emergence of pale white sprouts. When the first seeds begin to germinate, plant all of the seeds one-half inch deep and two inches apart in well-prepared beds that have been generously enriched with compost and a standard application of a balanced organic fertilizer. Keep the planting weeded well, and gradually thin parsnips to at least 6 inches apart.
For recommended planting dates for your local climate — and to design your garden beds — try our Vegetable Garden Planner.
Parsnips demand constant weeding for several weeks, but then the plants produce long, celery-like leaves that shade surrounding soil. Water as often as needed to keep soil constantly moist. In dry climates, mulch growing parsnips with grass clippings, chopped leaves or another organic mulch that helps retain soil moisture. Parsnips need more water than other garden crops, and should never be allowed to run dry.
Harvesting and Storage
Like carrots, parsnips push up out of the ground when they reach mature size. Use a digging fork to loosen the soil around parsnips before pulling them as needed in the kitchen. Immediately cut off the tops and wash and refrigerate parsnips, which will store in plastic bags in the refrigerator for up to two months.
In fall, many gardeners leave some of their parsnips in the ground, and harvest them as soon as new growth appears in early spring.
Parsnips that have been exposed to cold winter weather produce umbels of yellow flowers in early summer, with flattened seeds that resemble dill seeds about a month later. When the seeds turn dark brown, gather the seed heads in a paper bag, and allow them to dry indoors for a week. When thoroughly dry, shatter the seed heads and collect the largest seeds for replanting. Under good conditions, parsnip seeds will store up to three years, though two years is a safer guideline.
For growing advice for many more garden crops, check out our complete Crops at a Glance Guide.
Contributing editor Barbara Pleasant gardens in southwest Virginia, where she grows vegetables, herbs, fruits, flowers and a few lucky chickens. Contact Barbara by visiting her website or finding her on Google+.