Onions come in a variety of shapes, colors and sizes. At Plantura, we show you the best types of onions and tips for growing them in the garden.
It may surprise some, but others already suspect it: the onion (Allium cepa) belongs to the leek genus. The term "onion" may be a bit confusing in German, because in this case it describes both the plant species and the part of the plant called the onion, which is used to store nutrients and moisture.
There is something mysterious about the onion. On the one hand, its origin has not been clarified to this day, on the other hand, real wild forms can no longer be found. The species most closely related to the onion comes from what is now Iran and Turkmenistan. However, it is known from excavations that onions have been deliberately cultivated for more than 4000 years. The onion is therefore one of the oldest vegetable plants known to mankind. Consequently, it is not surprising that the onion is very varied.
Synonyms: Bolle, house onion, garden onion, onion, kitchen onion, summer onion, onion leek
Growing onions in the garden
The onion is a popular plant in your own garden. The cultivation is successful, the harvest is rich and the aromatic onions can actually be used by any hobby cook.
Sandy loamy soils and loess soils are particularly popular with onions. In general, the soil should have been loosened well before cultivation. It is essential to ensure that you do not introduce too much nitrogen into the soil. Also, no fresh manure may be added.
Onions can either be sown or planted. Again and again we receive inquiries as to whether onions can really be sown from the end of February. A resounding yes! is the answer. Because the onion seeds germinate at just a few degrees above zero. To avoid disease, bulbs should be sown (or staked) with a spacing of 10cm between plants and 25cm between rows. In climatically favorable regions, onion sets are planted as early as autumn. If the climate is a little rougher, you should wait until mid-May.
Fertilization is usually not necessary if you have prepared the soil well. While loosening the soil for planting, incorporate a portion of well-stored compost. If you overdo it with nitrogen fertilization, the green of the onion will grow rampant. However, this significantly delays the development of the onion.
You can find detailed step-by-step instructions here: Growing onions: sowing, care and harvest time.
Onion Varieties
The onion is very varied. This was hardly surprising to botanists, since the onion has many related species and has been cultivated since time immemorial.
You can find a comprehensive article on all common types of onions here: Onions: choosing the right types to grow.
Harvesting and storing onions
Except for the spring onions, all onions are harvested as soon as the leaves turn slightly discolored and begin to wither. Depending on the location and variety, the harvest can take place between July and September. If you use onion sets instead of seeds, you can generally harvest a little earlier. When harvesting, the onions are carefully lifted out of the ground. The foliage should also remain intact. If the weather is dry, the onions should ripen or dry outside in the sun for a few more days. During this time, the onion still draws substances from the leaves. When the foliage is completely dry, the bulbs can be hung on the foliage. Alternatively, you can also remove the foliage. Onions should be stored dry, not too cold and above all in the dark. Good storage varieties can be kept in a proper storage place until the following year's harvest. As a rule of thumb: the later and firmer the onion ripens, the better it can be stored.
Onions: ingredients and uses in the kitchen
The ingredients of the onion have been the subject of controversy for a long time. On the one hand, the onion is not particularly rich in vitamins. However, some minerals such as potassium, calcium and magnesium are included. However, the positive effect of onions on humans is said to be primarily due to their sulfur-containing compounds. These are said to have an antibacterial effect, which is why the consumption of raw onions is said to relieve colds in folk medicine. The onion contains about 30 kcal per 100g.
In the kitchenthe onion can be used in many ways. It is an essential component of soup vegetables and is good in salads or as a topping for bread. Fried and roasted, they are often served with cheese spaetzle or with onion braised meat. The onion can also be fried and then candied as a topping for steaks or burgers.
Pests and Diseases
Onions mostly grow he althy and robust. In some cases, fungal diseases such as downy mildew can attack the plants. A well-drained soil is important here, so that no waterlogging forms. Also, the plants should not be placed too close together. In this way, diseases can spread more quickly and the plants dry less quickly after rainfall. However, the onion fly is more important than downy mildew. They use the vegetables as a breeding ground for their offspring. This causes the onion to eat away. Rotting organisms can penetrate more easily. The onion then often begins to rot. If you don't get the offspring under control, they can lay their own eggs a few weeks later. A second generation of the pest then often infests the few remaining plants. A protective net is particularly useful as a countermeasure. This should seamlessly cover the onions from April to May.
The following products have proven themselves in our garden:
- Neudorff - Atempo copper fungus free: spray against many fungal diseases; environmentally friendly and not dangerous to bees.
- NEUDORFF - Fungisan rose and vegetable fungus-free: Beneficial pesticide, not harmful to bees with very good long-term effect
- NEUDORFF pest protection net: reliably protects your plants from pests
A popular variant of the onion is the shallot. We provide an overview of the cultivation, variety and harvest of the leek plant.