Question: How do you care for parsnips? Is it like growing carrots? -Pamela C.
Answer: A hardy biennial, parsnips are usually grown as an annual root crop.They look similar to carrots, only they’re usually a shade of white and oftentimes thicker. Unfortunately, I don’t lump parsnips in the “easy to grow” category. There’s a sort of finesse to getting their seeds to germinate. But, if you put the work in at the beginning of the season, you can just sit back and watch your plants take root!
To begin with, seeds lose viability after just a year or two, so having low germination rates is relatively common. Because of this, you’ll want to order new seeds from a reputable source every year.
Top-down shot of green parsnip tops growing in black soil in a wood framed raised garden bed, with grass growing around the base.
These take about 100 days to reach maturity, and are recommended by the Utah State University Extension particularly for growing well in Utah (USDA Hardiness Zones 4-8).
You can let parsnips go to flower and collect your own seeds, but keep in mind that they are biennials – you’ll have to leave them in the ground longer if you want to do this, since they don’t produce flowers until their second year. This can be an issue if growing space is already limited.
Although many seed packets suggest sowing seeds as soon as the soil is workable, it’s actually best to wait a bit longer until soil temperatures warm up to around 50°F, usually sometime in April.
A soil thermometer is helpful to ensure you don’t sow too early, but simply waiting two to three weeks after the spring solstice should be adequate. Any earlier, and seeds may rot before they have a chance to germinate.
Green ruffled parsnip leaves, growing in the sunshine in brown soil.
If you decide to risk it and sow seeds as soon as possible in the early part of the season, do yourself a favor and sow another batch of seeds a few weeks later anyway. They can take up to a month to germinate, so sowing a second batch will provide you with better germination rates.
Choose a sunny spot and sow seeds directly in the garden about 1/2 inch apart. When they germinate and start to put on new growth, thin them to at least 6 inches apart.
Top-down view of green parsnip seedlings, growing in brown soil in the garden.
Slow to get started, it’s common to plant another fast-maturing crop, like radishes, in between parsnips. The radishes will serve as a row marker, and planting this companion crop will make better use of your garden space. Beets, carrots, and salsify are also often planted with them.
Keep in mind that starting seeds indoors generally isn’t a good idea with root crops, since transplanting them can often result in misshapen roots.
To that same point, make sure your garden soil is rich, deep, and loamy. Parsnip roots can grow to be up to a foot long (sometimes longer, depending on the cultivar) and poor, rocky soil can also cause misshapen roots.
Vertical image of rows of parsnips and other vegetables growing in brown soil in the garden, with potted plants in the background growing in black plastic and orange terra cotta containers.
Although starting seeds indoors isn’t ideal, one option to speed up the germination of parsnips is to lay the seeds between two folded, moist paper towels and place them in a sealed container.
Keep them in a sunny window and check regularly for germination. Once the seeds start to sprout growth, sow them in the garden and take care to keep the soil moist, but not wet.
This can be a bit of a balancing act, but seeds won’t germinate if the soil is too dry. Too wet, however, and seeds will likely rot.
In areas with long, cold winters, getting a head start on germination is especially helpful. Parsnips require nearly the entire season to mature, so you really only get one chance at growing them each year (similar to tomatoes and peppers).
Repeated harvests (like carrots are so great for) really aren’t possible. So be sure to sow viable seeds, and plant them at the appropriate time.