Radish is a fast-growing, he althy vegetable and can be grown almost all year round. With us you will learn everything about the origin and properties of the cabbage plant and about planting radishes.
The garden radish (Raphanus sativus var. niger) is one of the most popular vegetables in Asia. In Germany, the beer radish is better known - but the radish can be used in a much more diverse way. We present the radish, its properties and requirements and also give tips on planting and caring for it.
Radish: origin and properties
The radish, also known as radish or radishes, belongs to the cabbage family (Brassicaceae). It is closely related to Radish (Raphanus sativus var. sativus) and Fodder Radish ( Raphanus sativus var. oleiformis) related. Radish probably descends from field radish (Raphanus raphanistrum), which is native to southern Europe and Asia. The cultivated form of the radish probably only reached Germany in the 13th century. Today it is used worldwide as a vegetable plant. The word radish or radi comes from the Latin "radix" which means "root".
Radishes form thickened roots from parts of the root and the shoot, the so-called hypocotyl. The round, oval or cylindrical radishes can be white, pink, red, violet, green, brown or black on the outside. Inside is the white, green to magenta-colored beet flesh with its aromatic, hot, sweet taste. Like all cabbage plants, the radish also contains various mustard oils, which are responsible for the typical, cabbage-like, hot taste. They have an antibacterial effect, which is why radish can be processed into cough syrup.
The radish root can reach deep into the ground and hardly forms side roots. The leaves of the radish initially form a basal leaf rosette with serrated, lobed to pinnate individual leaves, some of which have long stalks. At the flowering time, the radish plants stretch in length andform high flowering shoots, which are covered with alternate leaves. The long-day plants only flower when the length of the day has exceeded a certain number of hours. This is usually the case between May and the end of June. The radish blossoms appear on shoots that are 120 - 200 cm high. They grow in bunches and have white to pink flowers with some dark veins. Radishes are self-sterile, therefore strict cross-pollinators and dependent on insects. The flowers therefore provide both nectar and pollen. After pollination, elongated pods form in which the angular, reddish-brown to dark-brown radish seeds ripen. Even when the pods are ripe, they do not burst open, unlike rapeseed (Brassica napus) or mustard (Sinapis). All parts of radish are edible: the leaves, flowers and young pods can also be used in the kitchen.
What is the difference between radishes and radishes? Radishes and radishes belong to the same species, but each is a different variety. Radishes are often significantly larger and longer, their taste is more aromatic, while being sweet to pungent. Radishes, on the other hand, have a mildly hot taste and are harvested after a few weeks as tender, small turnips. However, they are so closely related that they can interbreed if they flower at the same time.
Planting radishes: sowing, location and Co.
The optimal location for radishes is on light to medium-heavy, crumbly soil with good water supply in full sun to semi-shade. On soil that is too light, radishes tend to become furry and extremely pungent. On the other hand, the radish root cannot be well developed and harvested with difficulty on soil that is too heavy. Silting or heavy soils with a tendency to waterlogging are unsuitable, but can be improved with a compost-rich potting soil such as our Plantura organic tomato & vegetable soil and sand. The introduction of organic matter also improves the soil in the long term, since soil life is promoted and humus formation is increased.
Radishes are sown directly outdoors or in a cold house, depending on the type of cultivation and variety. Pre-cultivation is possible, but direct sowing results in much nicer beets and deeper roots, which makes maintenance and harvesting easier. Some radish varieties are suitable for summer cultivation with sowing in the spring, others are used as storable autumn and winter radishessown Aug. Radishes can also be cultivated over the winter in unheated, sheltered cold houses.
Due to the large variety of varieties and their cultivation at different times of the year, radishes can be sown in batches every two weeks and can therefore be harvested almost all year round. First, the soil is tilled, removing unwanted weeds and generously loosening the soil. The radish seeds are then sown closely in rows with a distance of 25 - 30 cm and later separated with a distance of 20 cm between the individual radish plants. The seed is placed 1 - 2 cm deep in the ground or potting soil and watered vigorously. At an optimal germination temperature of 14 - 15 °C, the first seedlings can be seen after 8 to 10 days.
Good and bad neighbors for radishes: A mixed culture of radishes is very worthwhile, as some planting partners keep pests away and do not transmit diseases. Good neighbors for radish are lettuce (Lactuca), carrot (Daucus carota), celery (Apium graveolens ), Salsify (Scorzonera hispanica), Spinach (Spinacia oleracea), Tomato (Solanum lycopersicum), Paprika (Capsicum annuum), pea (Pisum sativum) and bean (Phaseolus vulgaris). Bad plant neighbors, on the other hand, are related brassicas (Brassica), cucumbers (Cucumis sativus) and onions (Allium cepa ).
Fast-growing radish varieties can be grown as a previous or second crop. In the greenhouse, the hot beets thrive optimally in early spring and are harvested by the beginning of May when tomatoes, peppers and the like move in. Autumn and winter radishes can be sown from August as a follow-up crop after early carrot varieties, bush beans, peas or lettuce. Radish should not be grown directly after other brassicas to avoid the dreaded clubroot (Plasmodiophora brassicae). A break in cultivation of four to five years is therefore recommended.
The right care
Caring for radishes is quite easy, also because the culture is fast-growing. Two to three weeks after sowing, the seedlings are separated to their final distance. Regular hoeing between the rows reduces the growth of weeds, which is particularly important inthe seedling phase is important. We present further care measures in the following paragraphs.
Water and fertilize
Fertilization and irrigation are important when growing radishes, as drought, heat and nutrient deficiencies result in furry, acrid and woody beets. In extreme cases, the radishes shoot out of stress and bloom prematurely. A regular water supply is therefore particularly necessary in dry periods.
Radish is one of the average consumers and should be supplied with sufficient nutrients, especially at the time when the beet is developing. Our Plantura organic tomato fertilizer is specially tailored to the needs of tomatoes and other types of vegetables. It works over a period of about three months and slowly and evenly releases the nutrients it contains. This effectively prevents the plants from being washed out or over-fertilized. The animal-free granular fertilizer can be worked into the surface of the soil when loosening it for sowing. Fresh manure or compost should not be incorporated just before sowing radishes as this is far too harsh for radishes and can damage the plants.
Common diseases and pests on radishes
Radish is a fairly robust vegetable plant, but various pests and diseases can occur under unfavorable growing conditions:
- Ferry Fleas (Psylliodes): Tiny, leaping, shiny black beetles cause sieve-like holey leaves. Regular inter-row hoeing, fine-mesh vegetable protection nets, and tansy broth reduce infestation.
- Cabbage Fly (Delia): The maggots of the cabbage fly feed on the roots of cabbage plants and young plants often die off entirely. Vegetable protection nets and a mixed culture with tomatoes and celery keep cabbage flies away.
- Mealy cabbage aphid (Brevicoryne brassicae): White-grey aphids suck on the young shoot tips. Beneficial insects against aphids and a mixed culture with beans reduce infestation.
- Leaf spot disease: Various fungal pathogens cause dark spots on the leaves, which are often not dangerous themselves, but indicate other diseases or pests on the radish.
- Downy mildew (Peronospora parasitica): On the underside of the leaf, grey-white fungal growths form, which are reflected as yellow spots on the upper side. Warm and humid weather promotes the disease, so adequate ventilation and planting distances should be ensuredbe respected.
- White rust (Albugo candida): Shiny white fungal pustules on the underside of the leaf appear especially in high humidity and spread quickly through wind and water in the crop. Affected leaves should be removed and disposed of with household waste.
Are radishes hardy?
Young, harvest-ready radishes are not hardy and are therefore harvested and stored in their entirety in autumn. Fully grown autumn radishes can withstand temperatures as low as -9 °C and can theoretically be harvested all winter long if the ground is frost-free, but they are often too woody at this stage. The beets can also burst open during frost and are then no longer edible. Winter protection with foil or fleece or the cultivation of radishes in an insulating, unheated greenhouse is a better alternative to outdoor cultivation if the beets cannot be stored.
The first aromatic radish beets can be harvested just a few weeks after sowing. We give tips on harvesting and storing radishes.