Parsnips

Parsnips look like white carrots, well, because they are related!

Cousin to carrots, parsley, celery, and other umbels, parsnips (Pastinaca sativa) are native to Eurasia and have been cultivated since ancient times. In fact, parsnips were used as a sweetener before sugar cane made its way to Europe!

Parsnips (Lebensmittelfotos) Pixabay

Parsnips are a cool weather crop in Mediterranean climates. Parsnips can be planted in September, and then again in February, March, and April in our region. If you live in a different area, simply check with your local Cooperative Extension Office for your best planting times.

Parsnip plant description

Parsnips leaves look almost like ferns, with pinnate (branched), toothed edges (margins). Parsnips are grown as annuals, but if you let a few of them go to seed, these biennials can start spreading edible roots in many areas of your foodscape. [Once they start that process, you won’t want to eat them - they get quite woody.] Second year plants can grow 5 feet tall, but your first year parsnip will be significantly shorter, at only 18 to 24 inches. Yellow, umbrella-shaped flowers grow into tiny ‘fruits’ called schizocarps. [How’s that for a fun garden word?]

​How to grow parsnips

Parsnips, like other root crops, need loose soil. This makes them well suited to raised beds and container gardening. If you are planting parsnips in heavy clay soil, you will want to break up the soil down 18 inches and dig in 3 or 4 inches of aged compost. If you don’t, you will end up with forked and otherwise deformed roots prone to disease. Parsnip seeds should be planted 1/2 inch deep, with a heavy dose of patience. Parsnips seeds are slow to germinate and the plants take up to 4 months to reach harvestable size, but they are worth the wait! These sweet roots lend themselves to seasonings such as ginger and nutmeg, as well as more savory dishes, such as soups and stews. Parsnips can be grown in full sun or partial shade. They prefer slightly acidic soil, so you may need to make some pH adjustments. Seedlings should be thinned to stand 3 to 6 inches apart and be sure to eliminate all competition from weeds.

Flowering parsnip, second year (Skogkatten) CC BY-SA 4.0

Parsnips pests and diseases

​I had a difficult time tracking down parsnip pests and diseases on the West Coast. Other regions had plenty to say, but my guess is that that region is not conducive to growing parsnips commercially, so it gets less attention. Being more than a little determined, I am going to try growing them anyway! 

It is my guess that, being a close cousin to carrots and parsley, parsnips will probably have many similar problems. These include armyworms, cabbage loopers, and aphids. Fusarium wilt, powdery mildew, bacterial leaf spot, and alternaria leaf blight may also occur. Other regions mention how celery fly larvae may tunnel into parsnip leaves, much like leaf miners. These pests can harm young plants, so remove infested leaves if you see them. I also found plenty of warnings about carrot flies. Carrot fly larvae are likely to attack parsnip roots, providing points of entry for canker and other fungal diseases. These pests are attracted to the smell of bruised plant tissue, so be gentle to your parsnips!

According to Wikipedia, parsnip canker is a real problem when growing this crop. Parsnip canker shows itself as orange-brown or black areas on the crown and shoulders. Also, the roots will crack. This condition is more likely to occur when seeds are planted in cold, wet ground that is too alkaline. It sounds, to me, that poor drainage is a parsnip’s worst enemy.
On the upside, many moth and butterfly larval forms use the flowers and undeveloped seeds of second year parsnips as a major food source. So, allowing a few parsnip plants to complete their lifecycle not only gives you free parsnip seeds and plants, it also adds biodiversity to your landscape and provides food for many beneficial insects!

Harvesting parsnips

Like many other root crops, parsnips taste sweeter after they’ve experienced a little frost. Since our ground is not likely to freeze, we don’t need to worry about getting our parsnip harvest out of the ground before it does. Other regions are not so lucky. Before you harvest your parsnips, however, be sure to wear gloves. Parsnips may be good sources of folic acid, potassium, fiber, and vitamins C and K, but they also have a powerful self-defense mechanism. Parsnip sap is toxic. If your skin is exposed to sunlight after handling parsnip leaves and stems, you are likely to get a rash. So, wear gloves.

Give these sweet root crops a try this winter and let us know what you think!