5 Tips For How To Grow Straight Parsnips

When you harvest your parsnips, do you pull out a knotted or deformed root? It is just as frustrating when the root has forked and breaks off in the ground. Deformed parsnips are common in many gardens, and here are some simple tips to prevent them.

To grow straight parsnips, the most important place to start is to provide loose soil that is free from rocks and debris. Using limited, or no, fertilizer will also help your parsnips grow straight. Growing healthy plants, including protecting them from root-knot nematodes, and taking extra care if you are transplanting them will also help produce nicely formed parsnips.

Parsnips can be difficult to germinate in many gardens. Even before the leaves have emerged above the ground, you want to do all you can to make sure these finicky roots aren’t stunted, twisted, or forked. There are five main ways to make sure your parsnips grow healthy and straight.

  1. Create a good soil texture
  2. Don’t use too much fertilizer
  3. Support health plant growth
  4. Protect your parsnips from nematodes
  5. Take care when transplanting

Read Next: How to grow parsnips in containers.

1. Create A Good Soil Texture

When its leaves have just emerged above the ground, a parsnip has already sent down a thin root that is nearly 10cm (4″) long. This taproot swells into the edible parsnip that we eat, and this thin root can easily get bent and twisted by any obstacles it encounters. That is why it is very important to create a good soil environment before you sow your parsnip seeds.

To grow nice and straight, parsnips need loose soil with a fine tilth (or texture). It should be worked to a depth of at least 15cm (6inches) but deeper is even better as most of your parsnips will have roots deeper than that. Tilling is a good option to create a fine tilth, but there are no-till options that work well, too.

When tilling or loosening your soil, it is also important to see how deep your topsoil is and see what is below that. In our area, we have 15cm to 20cm (6-8inches) of topsoil resting on top of clay. For parsnips, it is important to loosen the clay so the parsnip taproot can penetrate the dense soil and grow without stunting. When loosening the clay, or whichever subsoil you are working with, you don’t want to mix the subsoil with the topsoil if it can be avoided so set your tiller to the depth of the topsoil.

Nice soil by Carmen Edenhfer
Image by Carmen Edenhofer

Parsnips also benefit from the addition of humus, rotting leaves, and other carbon-rich matter. This will help make the soil light with good aeration, both of which benefit root growth. Of course, make sure that is it well incorporated to avoid clumps that will disfigure the growing roots.

To grow straight parsnips, it is also important to remove any obstacles in the soil, such as rocks, hard clumps of soil, or other debris. If a parsnip root encounters any of these obstacles, it will bend, twist, or fork and you will risk breaking the vegetable during harvest.

2. Don’t Use Too Much Fertilizer

Parsnips are a light feeder, meaning their nutrient requirements are not very high. You can often grow them with little to no fertilizer. Too much fertilizer can actually cause your parsnips to become woody and hairy. This is especially true if you provide too much nitrogen.

If you do fertilize your parsnip patch, make sure you do it well in advance so it has plenty of time to completely break down. If it is not fully broken down, the fertilizer may for small clumps in the soil that may burn the root, or cause it to become misshapen as it tries to push through.

3. Support Healthy Plant Growth

Just like people, the healthier your parsnips are the fewer problems you will have. Keeping your parsnips healthy enables them to better overcome any hardships they encounter. There are several ways you can improve the health of your parsnips.

First and foremost, good health starts with a healthy diet. Even if fertilizer is unnecessary, a healthy amount of compost incorporated into the soil before planting will provide everything your parsnips need to grow. Not only will this improve soil texture as we discussed earlier, but it creates a healthy, vital soil that all plants, including parsnips, thrive in. Make sure your compost is well-rotted to avoid clumping and to ensure that you won’t introduce new weed seeds. Parsnips are easily chocked out by competing weeds when they are young, and the weeds’ roots can disturb the immature taproot, causing it to deform.

Also like people, your parsnips need water to stay healthy. About 2.5cm (1inch) of water is sufficient each week. Sufficient water will cause the taproots (which are composed of nearly 90% water) to grow strong and thrive. Too little water will create, stunted roots that are woody and hairy.

Parsnips by Ali Eminov
Image by Ali Eminov

4. Protect Your Parsnips From Nematodes

Nematodes are small organisms that inhabit the soil. There may be 30 million nematodes in a square meter, and while many are important and beneficial, some are detrimental to your garden. In many gardens, the root-knot nematode is the main cause of deformed parsnip roots. These nematodes feed on the roots and cause knots to form. Where these knots develop, a parsnip cannot properly absorb water and nutrients, and the root becomes stunted and deformed.

Crop rotation is vital in dealing with this pesky organism since nematodes can overwinter in the soil. It is also worthwhile to buy parsnip varieties that are resistant to nematodes if they are a problem for you.

Tilling not only helps with soil tilth, but it is a good control method for dealing with root-knot nematodes. Tilling exposes nematodes to the surface where they quickly succumb to the elements, and it introduces other organisms that prey on the destructive nematodes.

5. Take Care When Transplanting

If you are starting parsnips in pots for transplanting, this can be a big cause of deformed and crooked roots. Since parsnips already have such a long taproot when the green emerge, it is very difficult to find a pot that will sufficiently hold them. Some garden supplies sell extra-tall pots that would work well. A free and green option is to germinate the seedlings in toilet rolls. Parsnips can be grown in toilet tubes similar to carrots, but parsnips would need to be transplanted just after the seedlings emerge to avoid outgrowing the “pot.” Take great care when planting them into the garden to cause as little impact on the roots as possible.