Growing Parsnips (8 Important Things to Know)

Many gardeners are keen to grow parsnips for their sweet and delicious roots that are ideal for roasting or making a lovely soup in winter. While parsnips are relatively easy to grow, gardeners that have never grown them do have questions about all aspects of their growth.

Here are eight important things to know about growing parsnips.

Growing Parsnips From Seed

As you may be aware by now, parsnips must be grown from seed and cannot be successfully grown from already germinated seedlings. This is because the seed first produces a long taproot that will stretch down into the soil. This taproot becomes the vegetable that we harvest and consume.

To grow parsnips from seeds, you first need to prepare your patch of ground. Fork the soil over well to ensure that it’s loose and friable and doesn’t contain any rocks or stones.

Muséum de Toulouse , CC BY-SA 4.0, via Wikimedia Commons

Once you’ve done this, create a shallow drill or furrow around ½ inch (12 mm) deep. Sow the seeds, spacing them evenly around 2 inches (5 cm) apart. Not all seeds will germinate, so this ensures that you’ll have a full row of parsnip plants.

Cover the seeds with soil and firm them down lightly to ensure that the seeds are in contact with the soil. Water carefully, making sure not to dislodge the seeds.

Ensure that you keep the soil nice and moist for the next two or three weeks until you start to see some seedlings emerging. Continue to water the soil for another couple of weeks until all the seeds that are going to germinate have done so.

If too many seeds have germinated, you’ll have to thin them out until you have one plant every 8 inches (20 cm). This should give the plants enough room to grow successfully.

Germinating Parsnips

Parsnip seeds need to be fresh in order for them to germinate successfully. Seeds that are older than one year are unlikely to germinate successfully. Therefore, if you want to grow a lot of sweet, tender parsnips this season, make sure that you use only fresh seeds.

Parsnip seeds also need warm soil to germinate. The soil temperature should be at least 46 degrees Fahrenheit (8 degrees Celsius). However, it’s better to wait until the soil has reached a temperature of 54 degrees Fahrenheit (12 degrees Celsius) if you want even germination of your parsnip seeds.

In general, parsnip seeds will take around 2 to 4 weeks to germinate, but you can hasten up the process by pre-germinating indoors. In a shallow dish, place some damp paper towel and space your seeds out on this. Leave this in a warm spot for a couple of days or more, ensuring that the paper doesn’t dry out.

Once you start to see, some white shoots appear from the seeds, plant these directly into the soil. If you’ve spaced the seeds around 2 inches (3 to 4 cm) apart, you can just place the entire piece of paper towel complete with seeds just below the surface of the soil in your vegetable patch.

Another idea is to plant your parsnip seeds into toilet paper or paper towel rolls filled with compost. Keep these in a warm spot indoors and keep them moist. Once the seeds have germinated, thin them out so that you only have one seedling in each tube and then plant the entire tube into the garden.

Parsnip Spacing

When sowing your seeds, you need to space them correctly so that the plants have plenty of room to grow. Here’s a recommended breakdown of parsnip spacing:

  • Seeds should be sown no deeper than ½ inch (12mm) below the surface of the soil
  • You can space the seeds around 2 inches (5 cm) apart or you can place 2 to 3 seeds in the same spot and space these groupings of seeds around 8 inches (20 cm) apart.
  • Once the seeds have all germinated, thin them out so that you end up with one seedling every 8 inches (20 cm).
  • If you’re planting more than one row of parsnips, the rows should be spaced 18 inches (46 cm) apart.

When to Pick Parsnips?

Parsnips are best picked once they’ve gone through at least one period of frost. Once the roots have experienced some frost, they’ll increase their sugar content and be much sweeter and more flavorsome.

Most parsnip plants will reach maturity in around 95 to 120 days. At this stage, the green tops will start to die down. This is then a clear indication that your parsnip roots are ready for harvest.

You can harvest as many or as few of the roots as you wish or need at the time. The rest of the roots can be left in the ground and harvested as needed. Once the tops die down, the roots will not continue to grow.

This means that you can leave them in the ground all throughout winter and continue to harvest them. In order to make this easier, make sure that you cover the ground with a thick layer of hay or straw to prevent the soil from becoming frozen.

Once the weather starts to warm up in spring, and the soil temperature rises, make sure that you quickly harvest the remaining parsnips that are still in the ground. If you fail to do this, the plants will initiate new growth, and the roots will become inedible.

Parsnip Companion Planting

Companion planting is all about growing different plants that have the same growing requirements close together so that you have a very productive vegetable patch. In addition, companion plants add various forms of protection for their companions.

Some attract beneficial insects for optimum pollination, while others deter certain insects that might otherwise decimate a crop.

Let’s look at a few different plants that make perfect companions for growing next to parsnips:

  • Bush beans. Beans are legumes. This means that they have the unique capability to fix nitrogen into the soil. And, we all know that nitrogen is an essential element for lush plant growth. Bush beans also have shallow roots so they won’t compete for nutrients with the much deeper roots of the parsnip plants.
  • Garlic. This is another useful vegetable to add as a companion plant. It also has shallow roots that won’t compete for water or nutrients with the deeper roots of parsnips. The scent of garlic is also a useful deterrent to many pests such as the carrot root fly larva.
  • Lettuce. This quick-growing vegetable has shallow roots so it makes a perfect companion for parsnips.
  • Radish. Radishes are the perfect companion plant to parsnips because they’re fast growers and fairly shallow rooted. Many expert gardeners sow radishes at the same time as they sow their parsnip seeds. The radishes will be up and growing well before the parsnips have even germinated. This is one of the clever ways to get the most out of your small garden patch.

Parsnip Growing Season

Although they’re considered a cool-weather vegetable, parsnips do most of their growing during the warmer months. You see, the seeds need relatively warm soil to be able to germinate effectively.

Parsnip seeds can be planted from spring right into late summer as long as the soil is nice and warm. Remember that the soil needs to be kept moist in order for the seeds to germinate well.

The green tops of the plants will grow throughout the warmer months, and at the same time, the roots will develop and thicken below the surface of the soil. It takes around 95 to 120 days for each parsnip plant to reach maturity. At this stage, the green tops will die down, and the roots will stop growing.

It’s a good idea, though, to leave the roots in the ground until there’s been a frost or two. This is because the roots will become much sweeter and have more flavor after they’ve been exposed to frost. That’s why parsnips are regarded as a cool-weather crop – the tops grow during the warmer weather, but the roots need some cold in order to fully develop their flavor.

Can You Plant Parsnips In Fall?

It is possible to plant parsnips in the fall, but it depends on where you live. Remember that the plants need around 95 to 120 days to reach maturity.

Therefore, if you live in an area that gets really cold winters where the ground freezes, planting your parsnips in the fall may not give them enough time to reach maturity before the ground becomes frozen.

However, in areas with milder winters where the ground doesn’t freeze, it’s quite possible to plant parsnips in the fall and then harvest them in early spring.

Can You Grow Parsnips In Raised Beds?

Parsnips are perfect for growing in raised beds as long as the beds are deep enough. To produce lovely long taproots, parsnips need to be planted in beds that are around 24 to 36 inches (60 to 90 cm) deep.

Because you have total control of the type of soil that you fill your raised bed with, growing parsnips and other root vegetables is ideal, especially if you fill your beds with friable, open soil that is not compacted or full of rocks or stones.

This makes growing parsnips much easier because you don’t have to dig over the soil really intensely before planting your parsnip seeds.

Using raised beds to grow your parsnips in also means that they’ll be much easier to harvest, and you’ll be able to prevent the soil from freezing by adding a generous layer of straw or hay on top of the soil in the beds before the first big freeze hits.

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