Growing Root Vegetables - Top Tips

From carrots to radishes, to horseradish, root vegetables are a group of crops you can grow as a staple part of your vegetable plot. With recent innovations in growing your own crops, you can grow them successfully in troughs and in containers too.

Different varieties of root vegetables have their own characteristics and growing seasons, and you can get a lot of information for individual crops from seed packets alone.

Root vegetables can be split into two types of plants:

  1. Tap roots - this type sends a long tap root into the soil
  2. Swelling plants - this type tends to swell its roots into the soil

Top tips for growing root vegetables 

1) How to prepare the soil for root vegetables

For successful harvests, the key is to prepare the soil well before sowing. Root vegetables prefer a well-drained, loose soil that retains a degree of moisture.

You can achieve this by digging the soil well in winter prior to sowing, remove rocks, and add a bulky compost.

Root vegetables prefer an almost neutral pH soil, meaning that it is slightly acidic. If your soil is particularly acid, which you can assess using a litmus or pH testing kit, add lime which will increase the pH. Adding the fresh compost or manure just before planting will cause the soil to be too alkaline. This is what causes ‘forked’ carrots.

2) Provide root vegetables with the right spacing

Root vegetables need adequate space to be able to grow at their best. This can be achieved before they have started growing by taking the time to sow them the correct distances apart.

To ensure that they have enough space whilst growing; thin out the young seedlings when they’re 3 to 4 weeks old. This can be done by either pulling them out or snipping them until they’re properly spaced. Different root vegetables have their own spacing requirements when they are planted.

3) How to take care of root vegetables - Feeding

Plants put on good root growth mainly through the intake of phosphorous. In winter you can feed a great number of ornamental and cropping plants with a feed high in phosphorous.

With vegetables like parsnips and radishes you want to enhance the swollen root as much as possible. Feeding with a high phosphorous feed (e.g Bone Meal Root Builder) NPK 4:20:0 will bring on strong root growth.

4) How to take care of root vegetables – Watering

It is important to not let your root vegetables dry out when they are starting to swell. Consistent and even watering is important to enable the right conditions for optimal growth.

5) Grow root vegetables to improve soil texture

Digging is an effective means to aerating and introducing oxygen into the soil profile, giving roots a healthy environment in which to grow.

Another way of breaking up soil that has compacted, is growing root vegetables. Their swollen roots - or underground stems in some cases – actively break up clumps as the roots enlarge, growing longer in the case of many carrots, or more bulbous in the case of some turnips or radishes.

After a year of growing root vegetables, you have a head start in preparing the soil for next year as the harvestable crop has actively broken up soil clods while growing.

6) Root vegetables as ornamentals

Why not add one or two vegetable plants to your flower bed. Parsnips and carrots belong to the umbelliferous family of plants that not only produce tap roots but also lovely delicate lace-cap flowerheads that look like clouds floating about delicate thin stems. Parsnip is a great-looking plant in the flowerborder and has been used in show gardens at the RHS Chelsea Flower Show for its airy, and delicate growth that wouldn’t be out of place in a cottage garden.

7) Root diseases to watch out for

A disease that carrots, parsnips, swedes, turnips and radishes are all susceptible to is black rot, which spoils root crops rendering them ugly and inedible.

The first signs of black rot are the leaves yellowing and have black veins. You can prevent this disease, exasperated by warm and wet summers, by practising crop rotation and making sure the soil is well drained.