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 glean a lot of information for individual crops from seed packets alone.
Here are some general pointers in growing root vegetables.
1) 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.
2) Prepare the soil well
For successful harvests, the key is to prepare the soil well before sowing. Root vegetables prefer a well-drained soil that retains a degree of moisture. You can achieve this by digging the soil well in winter prior to sowing and adding bulky compost. Fresh manure, helping to create a well-draining and moisture retentive soil, is to be avoided as it’s too strong and causes crops to branch. This is what causes ‘forked’ carrots. They also prefer a soil that is almost neutral in pH – so very slightly acid. If your soil is particularly acid, which you can assess using a litmus or pH testing kit, add lime which will increase the pH.
3) Feed the right fertiliser to improve size and quality
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) 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.
5) 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. You’ll notice black lesions forming on carrots near to the carrot heads when they are in store. On turnips, you’ll see a black ring formed on the inside edge of the crop when they are in store. When growing, if you notice the leaves are yellowing and have black veins. You can prevent this disease, exasperated by warm and wet summers, by practicing crop rotation and making sure the soil is well drained.