Parsnips (Pastinaca sativa) look like colorless carrots, but they have their own complex, sweet and spicy, earthy flavor. They are a cool-season root vegetable and are technically a biennial (completing their life cycle in two growing seasons) but they usually grown as an annual. Parsnip roots grow from five to ten inches long on average. And the plant produces a rosette of upright green foliage above the ground. Parsnips have a fairly slow growth rate. They’re typically planted in the spring but also can be planted in the fall in some areas. Note that the sap in parsnip plants can be toxic to people.
|Botanical Name||Pastinaca sativa|
|Plant Type||Biennial, vegetable|
|Size||1–3 ft. tall, 6–12 in. wide|
|Sun Exposure||Full sun, partial sun|
|Soil Type||Loamy, moist, well-drained|
|Soil pH||Acidic, neutral (6 to 7)|
|Bloom Time||Summer (second year)|
|Hardiness Zones||2–9 (USDA)|
|Native Area||Europe, Asia|
|Toxicity||Toxic to people|
How to Plant Parsnips
When to Plant
Parsnips grow well in most regions, though they require a long growing season and have the best flavor when they can be grown during relatively cool months. It can take from 120 to 180 days for parsnips to go from seed to harvest. So in some regions they are grown as a winter crop, planted in the middle of the fall and harvested in late winter or early spring. However, in cold regions where the ground freezes solid, parsnips are planted in the early spring as soon as the ground can be worked and harvested the following fall.
Selecting a Planting Site
Select a planting site with loose, well-draining soil. Make sure it’s free of rocks that can inhibit root growth and free of weeds that can compete for nutrients and moisture. Growing in a container is an option, although it is not recommended because a container does not provide optimal conditions for the roots to develop.
Spacing, Depth, and Support
Sow the seeds about 1/2 inch deep. Add roughly two to three seeds per inch in rows that are 1.5 to 2 feet apart. Once the seedlings are a few inches tall, thin them to three to six inches apart. When thinning, cut off the plants at ground level rather than pulling them to avoid disturbing the surrounding plants. A support structure won't be necessary.
Parsnip Plant Care
Parsnips prefer to grow in full sun, meaning at least six to eight hours of direct sunlight on most days. However, they can tolerate some shade.
Ideal soil conditions are deep, rich, and loamy with sharp drainage. Parsnips prefer a slightly acidic to neutral soil pH. Thoroughly loosening the soil roughly a foot down prior to planting will ensure good root growth.
Regular moisture encourages strong and consistent root growth, about one inch of water per week. Water slowly and deeply. Frequent, shallow watering can result in weak roots. However, make sure the plants are never sitting in waterlogged soil.
Temperature and Humidity
Parsnips grow best in average temperatures between 45 and 70 degrees Fahrenheit. They will tolerate freezing temperatures at both the beginning and end of the growing season. Parsnips have no preference when it comes to air humidity.
Mix a few inches of compost into the soil at the time of planting. Then, side-dress with some compost at midseason.
Parsnip plants are pollinated both by insects and the wind.
Types of Parsnips
Here are several varieties of parsnips:
- 'All American' is very sweet and fine-grained with a small core.
- 'Hollow Crown' has a mild honey flavor and uniform roots with few side roots.
- 'Harris Model' appears early in the season and has tender flesh.
- 'The Student' has large roots with a mild nutty flavor, and it requires a long growing season of about 180 days.
- ‘Gladiator’ is a canker-resistant variety that produces very thick roots.
Parsnips vs. Carrots
Parsnips and carrots are relatives. They are both grown for their edible roots, which are similar in appearance and texture. However, parsnips are typically white while carrots are orange (though they also can come in white, yellow, purple, and other colors). Flavor is the main difference between these root vegetables. Parsnips are somewhat spicy while carrots are sweeter.
Parsnip varieties mature at different times. When the roots are at least an inch in diameter, it’s time to harvest. When harvesting in the fall, it’s best to allow your parsnips to be exposed to a few frosts. This creates a sweeter flavor. However, be sure to harvest before the ground freezes.
To ensure you get the whole root, loosen the soil with a pitchfork before harvesting. Then, gently ease the roots out of the soil. Cut off all but a few inches of foliage. Parsnips can be stored in root cellar conditions between 32 and 35 degrees Fahrenheit with a humidity between 90 and 95%. Keep them in damp sand or sawdust, and they should last for four to six months.
How to Grow Parsnips in Pots
If you don’t have the garden space for parsnips, you can try growing them in a container. But you will need a very large container for the best root growth—ideally something at least 15 inches deep. The container also must have drainage holes. Unglazed clay is a good material becayse it will allow excess water to escape through its walls. A fabric grow bag is also an option to make the whole container lighter to move if necessary.
No pruning will typically be necessary when growing parsnips. But remove any damaged stems to avoid them introducing any pests or diseases to the plant.
Parsnips are typically grown from seed. And you can actually propagate your own plants by allowing some to go to seed in their second year. Here’s how to save seed:
- In the late summer, cut the mature seed heads off the plant.
- Place them in a single layer in a warm, dry spot with good air circulation to dry completely.
- Once the seed heads are dry, break them open and separate out the seeds.
- Store the seeds in an airtight container. They are best planted within a year, as germination will decrease as they age.
How to Grow Parsnips From Seed
Sow the freshest seed possible. Parsnip seeds germinate best in soil that’s between 50 and 75 degrees Fahrenheit. They can take between two and three weeks to germinate. You can expedite germination by placing your seeds between wet paper towels in a warm spot prior to planting them outside. Allow tiny roots to develop on the seeds, and then sow the seeds in the garden.
Potting and Repotting Parsnips
Use an organically rich, loose, well-draining potting mix for growing parsnips in containers. Also, only add one plant per container to avoid crowding the roots. Aim to use a container that will accommodate the plant's mature size right from the start, so you don't disturb root growth with repotting.
You can leave your parsnips in the ground to harvest throughout winter (if the soil is not frozen) and into the early spring. Add a thick layer of mulch to help protect them from freezing soil. They will sweeten toward the spring, as the plants get ready to begin growing again. However, once the tops resprout, the flavor will start to diminish and the roots will become tough and fibrous.
Common Pests and Plant Diseases
A few pests commonly bother parsnip plants, including aphids, leaf miners, and carrot flies. Avoid planting your parsnips where carrots or celery have recently been grown to help prevent the spread of shared pests. Moreover, canker is a disease that causes dark patches on parsnip roots. It mostly affects injured roots. If canker is a problem, choose resistant varieties of parsnip.
Are parsnips easy to grow?
Parsnips are fairly easy to grow in cool weather and loose, deep soil.
How long does it take to grow parsnips?
Parsnips can take 120 to 180 days from planting to harvesting.
Do parsnips come back every year?
Parsnips do technically complete their life cycle in two growing seasons; however, most gardeners harvest them during their first growing season.
“Pastinaca Sativa.” Ncsu.Edu, https://plants.ces.ncsu.edu/plants/pastinaca-sativa/