The fodder radish is an old crop that is planted as an oil crop and for green manure. We give you tips on how to grow fodder radish in the garden.
Oil radish is considered a fast-growing and deep-rooted plant with a high proportion of leaves. The seeds of the oil plant can be harvested. But the deep taproots also represent real added value for soil fertility in the garden. In this article you will learn everything about the cultivation, care and use of radish.
Oil radish: flower, origin and properties
The fodder radish (Raphanus sativus var. oleiformis) belongs to the cabbage family (Brassicaceae) and originally comes from warmer climes. The oldest records of the oil plant come from Egypt, but the exact origin or provenance is unclear. On long, rather thin stalks, the fodder radish forms alternate, elongated, oval pinnate and radish-like leaves. The annual plant is not hardy and produces flowers that are attractive to bees between May and June. This has the distinctive structure of four cruciform petals for cruciferous plants. The color spectrum of the flower ranges from yellow to white to purple. The plant, also known as melioration radish, reaches a growth height of 50 - 100 cm. A deep taproot anchors the radish underground in the ground. It was formerly bred for oil production, similar to oilseed rape (Brassica napus). Cultivation and use as an oil plant are currently in sharp decline. The oilseed is only still cultivated in Japan, China and Central Europe. Instead, the focus today is on the use of oilseed radish as green manure.
The best oilseed radish varieties
Oil radish varieties differ in their flower color, the radish formation of the roots, the fertility of the flowers and in their resistance to various diseases. Oil radish varieties that are resistant to harmful roundworms (nematodes) reduce the risk of infestation forsubsequent cultures. Potatoes in particular (Solanum tuberosum) also benefit, as plant nematodes can transmit viruses and cause potato diseases such as iron spot. There are the following oil radish varieties to choose from:
- 'Contra' is specifically suited for use as green manure. The variety is characterized by multi-resistance to various diseases, as well as nematodes. Unintentional sowing of the plant is reduced by a low tendency to bloom.
- 'Litinia' shows an attractive purple-white flower and convinces with its rapid growth and deep taproots on nematode-free soil.
- ‘Radetzky‘ has good nematode resistance and prevents any weed growth due to its rapid leaf growth. The fast-growing variety is suitable for almost any location.
- 'Romesa' is an oilseed radish variety for nematode-free areas. It is well suited as a preculture and as a green fodder plant for animals. If left standing for a long time, 'Romesa' begins to form seeds that serve as a source of food for birds, but may lead to unwanted growth in the following year.
- 'Rufus' is another hardy strain against nematodes. The plant shades the ground well even when young and is characterized by a high root mass yield. This is referred to as the so-called radish formation.
Tip: You can also find an overview of other radish varieties here.
Sowing fodder radish: step by step
The fodder radish is easy to cultivate. The radish does not make any special demands on the location. It grows on almost any soil. A sunny location promotes the ripening and drying of the seeds. However, a deep soil is helpful for a pronounced root development. Depending on the variety, sowing begins as early as March and can continue into autumn. Generally speaking, seed production should be done between March and May. If the fodder radish is used as a winter green cover that freezes over, sow between the beginning of July and mid-September. The seed is sown either by broadcasting or in rows. When sowing in rows, the distance between the rows should be around 20 - 40 cm. With regard to the sowing depth, 2 and 4 cm are ideal. Approximately 3 grams of seeds are needed per square meter. Germination occurs at temperatures above 2 °C andtakes about two weeks. Due to the low germination temperature, the seeds can still be sown in autumn.
The right care
The care of the oil radish is very easy. No special care measures are required during the cultivation period. In hot and dry periods during the seedling phase, the radishes should be watered. Once the long taproots have formed, the crucifer is drought tolerant. Fertilization is not necessary on most soils. Fodder radish can self-seed if grown early. This can be prevented by cutting back the flower stalks after flowering. If sown in late summer and autumn, however, the radish will not ripen. Fodder radish is largely robust to clubroot and is considered to be self-tolerant.
Is fodder radish hardy? The fodder radish is not hardy in most areas and freezes completely in winter at temperatures below -10 °C.
Oil radish as a catch crop and for green manure
Green manure is, to put it simply, the sowing of plants with the aim of improving soil fertility and increasing the humus content. Due to its large biomass and deep-reaching roots, oilseed radish is particularly suitable as green manure for slightly compacted, poorly draining and humus-poor soils. Areas at risk of erosion on slopes and embankments also benefit from green manuring with oilseed radish. Other cabbages should not be planted directly as a pre- or post-culture on the same bed.
In cold winters, the radish reliably freezes and the growth remains as a mulch layer on the bed. In the spring, the bed can be dug up and the organic matter can be supplied to the microorganisms. Our Plantura organic soil activator supports the work of the soil organisms with the help of the nutrients it contains and also brings plant-promoting mycorrhiza fungi into the soil. Alternatively, at the end of the cultivation period, the growth can also be chopped up in autumn before the first frosts and worked into the soil. Here, the mineralization of the nutrients takes place comparatively faster and the subsequent crop benefits more quickly from the green manure. However, the soil remains less protected from wind and water erosion.
Is radish edible?
Like all types of cabbage, fodder radish also forms antibacterial mustard oils that help destroy cells,when cutting or cooking, for example, develop a pungent, carbonaceous taste and smell. In principle, the entire oil radish is edible. Young leaves, like other types of cabbage, can be used in the kitchen. With increasing age, the foliage tastes increasingly bitter and pungent, which is why many animals only like to eat the fodder radish in mixtures with other forage plants. The flowers can be added to salads and other dishes as a pungent, edible decoration. Young and tender pods can also be prepared as green vegetables in the pan. The root of the oil radish is also edible, but it lignifies quite quickly in the young plant stage. Only the pods of the plant are used in commercial cultivation. After they are fully ripe, they are threshed in autumn and the oil contained in the oil radish seeds is pressed out.
Mustard (Sinapis) is a relative of oilseed radish and can also be planted as green manure or for seed production. In our special article you will find out everything about the mustard plant.