Days to germination: 14 to 20 days
Days to harvest: 100 days
Light requirements: Full sun to light shading
Water requirements: Consistent and regular watering
Soil: Loose and dug deeply, no extra fertilizer
Container: Not that suitable
Many people associate parsnips and carrots because they look much the same in the grocery store, and many aspects of growing them are the same. But the plants are not identical, and you should expect a few differences when it comes to the garden.
When it comes to root vegetables, carrots are more popular mainly because people are just more familiar with them. Orange carrots are more appealing in the grocery store compared to white parsnips, so they are more of an undiscovered vegetable. Grow a few and see which you like better.
Their flavor is stronger than a carrot, but can still be eaten either raw or cooked. The leaves are not edible, which makes them different than carrots in that respect. The roots are high in fiber, vitamin C, several B vitamins, iron and potassium.
Parsnips are biennial, meaning they take 2 years to produce their blossoms and seeds. If you intend to save any seed for future parsnip plantings, leave a few roots in the ground at harvest time. They will re-grow again in the spring and develop their flower stalks.
Starting from Seed
Parsnip is a typical root vegetable and does not do well when transplanted because of its long central taproot. It’s best if you plant your seeds out into the soil rather than start seedlings indoors.
To keep your parsnips from developing stunted or oddly-shaped roots, take the time to really dig the soil before you plant. At least 8 inches deep, or even an entire foot of loose soil is ideal. Remove all stones as well. You shouldn’t need any additional compost or nutrients.
You can plant your seeds fairly early in the spring, perhaps 4 to 5 weeks before your last frost date. Seeds should be about an inch underground but the soil covering them needs to be particularly loose. Parsnip sprouts aren’t overly strong, and crusted soil can keep them from coming to the surface.
Parsnip seeds aren’t great for germinating, so you should plant more seeds than you really need. Once they start to sprout, thin down to 1 plant every 3 to 4 inches if necessary. Be very gentle when thinning, using scissor or shears to snip away the extra seedlings. If you pull them, you may damage the roots of the remaining plants.
Parsnips are slow germinators, and their seedlings keep growing slowly once they’ve sprouted. They can easily get overwhelmed by weeds at the beginning, so you really need to take the extra effort to keep your parsnip area weed-free.
While your parsnips are growing, you shouldn’t add any manure, compost or extra fertilizer. The roots can develop too many side shoots, leaving you with very “hairy” parsnips. It won’t necessarily change their taste, but their appearance will be less than appealing.
To have nicely shaped parsnip roots, you should make sure to water your plants very evenly and consistently. Uneven growth spurts can cause the roots to grow crooked and even split.
Unlike carrots, parsnips do not come in short or dwarf varieties which makes them much less suitable for container growing. If you do want to try potted parsnips, you will need large pots at least 20 to 24 inches deep.
Large containers at that depth can have more than one parsnip plant, as long as you can have about 3 to 4 inches between each parsnip.
Pests and Diseases
Parsnips can have problems with insect pests both above and below the soil. The leaves can be damaged by celery leaf miners that eat little tunnels as they move around. If you see a network of tunnels in the leaves, pick off any damaged leaves and spray your plants with insecticide. Only pick off as many leaves as you can without killing the plant though.
Even more of a pest is the carrot rust fly. Though the flies may be on the surface, the damage is underground. These small flies lay their eggs around your plants, and their larvae hatch to eat the roots. Even when they don’t actually kill your parsnips, the roots aren’t worth eating.
Once the grubs are in the soil, there is very little you can do to protect your plants. You need to keep the flies from laying eggs in the first place. Covering your parsnip seedlings with mesh covers for the first few months (until approximately June) can make a huge difference. Once the fly season has passed, you can remove the covers.
Harvest and Storage
You can dig up your parsnips whenever you want as they can be harvested even when very young. While that is a common practice with carrots, it’s not usually what parsnip growers do. Leave them in the ground for the whole season, you’ll find they taste better after one or even 2 hard frosts in the fall.
The roots can be tough to pull out, so have a shovel handy to dig them out. If you try to harvest your parsnips by pulling on the leaves, you’ll likely end up with broken roots. Loose soil will make it easier, but a shovel or small pitchfork is very helpful. You probably should avoid planting your parsnips too close to other late-harvested plants so you don’t have to be too delicate while digging.
Like most root vegetables, parsnips store very well if kept in the right conditions. You can keep whole parsnips (unwashed) in any damp and cool location, as long as they don’t freeze. In a pinch, the fridge can do. They can last between 4 and 6 months.
In milder climates, you can even just leave your parsnips right in the ground and dig them up as you need them. The cold winter weather keeps them from growing any further, yet keeps them preserved just right. As long as your ground doesn’t freeze solid, this works well. A mulch of straw in the fall, can help for later winter digging.