- Green onions: origin and properties
- Differences between spring onions, spring onions & Co.
- The right care
- Are spring onions hardy?
- Propagating Spring Onions
Help the development of the site, sharing the article with friends!
Spring onions are easy-care vegetables that can be harvested almost all year round. We present the spring onion in a profile and give tips on how to care for it properly.
The spring onion (Allium fistulosum) is a type of vegetable that is particularly widespread and popular in Asia. In this article you can find out how to successfully cultivate and care for the perennial bulbous plant here.
Green onions: origin and properties
The spring onion is also known as winter hedge onion or spring onion. It belongs to the large family of the amaryllis family (Amaryllidaceae), more precisely to the subfamily of the leek family (Allioideae). The winter hedge onion originally comes from Asia, where it reached Central Europe from Russia thanks to its winter hardiness. Spring onions are reported to have been cultivated in China as early as 2,000 BC. The spring onion is still the most important onion there today. It is even used as a medicinal plant in traditional Chinese medicine. In Europe, this bulbous plant is commonly used as a perennial winter hedge. Meanwhile, in Asia, the plant is grown more as an annual than a spring onion and is harvested whole. A selection of the best spring onion varieties for perennial or annual cultivation can be found in our special article.
The winter hedge onion grows into a 50 - 80 cm high, clumpy perennial plant. Its tubular leaves are grassy to dark green in color and can be harvested all year round. At the base, the spring onion does not form a real, rounded storage onion. Instead, the elongated bulb merges directly into the leaves, forming a cylindrical stem that is white or reddish-pink in color, depending on the variety. Spring onions bloom between June and August in the second year. It is edible as well as the rest of the plant. The round inflorescences of the spring onion consist of many individual flowers, which are terminal on a tube-like flower stalkenthrone. All kinds of insects, especially bees (Apis), are busy pollinating the flowers in summer. After pollination, numerous, flattened and wrinkled black to dark brown-grey seeds form. These sit in three-chambered capsules, which dry out when ripe and rupture so that the seeds fall out.
Differences between spring onions, spring onions & Co.
Since there are often many synonyms for the leek and onion family, it is sometimes not entirely clear which species it is. The most important representatives of the Allioideae besides spring onions are the onions (Allium cepa), chives (Allium schoenoprasum ), garlic (Allium sativum) and leek (Allium ampeloprasum).
Leek and spring onion have a similar appearance, but there is one clear difference: the leek has flattened instead of tubular leaves and a much thicker stem. The name scallion is just a synonym for Allium fistulosum because the spring onion, like the leek, harvests the whole plant.
Confusion can quickly arise when choosing a variety, because even onion varieties that form a real storage onion very late can also be cultivated as "spring onions". These varieties of the species Allium cepa are completely harvested early as young onions. They are not hardy and do not form a nest with daughter plants. Such a clump is a collection of many genetically identical plant shoots, each of which can form a separate plant. The spring onion, on the other hand, is not able to form a thick onion. It remains with the slight, typical, cylindrical thickening. You can find more information about the distinction between bulbous plants here.
The right care
When growing spring onions, attention should be paid not only to optimal site conditions and correct planting or sowing, but also to care. We present the most important measures.
Watering and fertilizing
The spring onion is not particularly demanding when it comes to water supply, provided the location is right. However, freshly sown or planted spring onions need regular watering until they develop a sufficiently large root systemhave formed. In any case, avoid waterlogging. In hot summers, perennial plants that are already established should also be watered.
Onion plants such as spring onions are medium to weak consumers. Fertilizing in spring with mature compost or a predominantly organic long-term fertilizer, such as our Plantura organic tomato fertilizer, is usually sufficient for the whole year. The granules are applied around the plant clumps and worked into the surface. Soil organisms release the nutrients gently and evenly over the course of weeks. Over-fertilization or soil pollution, which quickly occurs with mineral fertilizers, is thus effectively avoided. If you only cultivate your spring onions as an annual, the fertilizer is added directly when sowing or planting early young plants.
Cut Spring Onions
Leek onions should only be cut when you are harvesting the leaves or to avoid self-sowing. When harvesting the spring onions, it is important not to cut them too low. The growth center of the plant must be preserved so that it can sprout again. Therefore, leave at least 5 cm of the stem when cutting the spring onions. Another reason to cut the spring onions is sowing. Because the ripe seeds fall off easily and form seedlings. To prevent this, you should cut out the inflorescences from the very bottom with secateurs or a knife after flowering in early August.
Common pests and diseases
Winter hedge onions are robust and hardy bulbous plants. They are rarely attacked by diseases or pests. Onion downy mildew (Peronospora destructor) can occasionally occur if the humidity persists. The onion fly (Delia atiqua) can also cause major damage. Avoid fresh compost as this encourages onion fly infestation. The best prevention is a mixed culture with umbellifers (Apiaceae) such as carrots (Daucus carota) or parsnips (Pastinaca sativa).
Are spring onions hardy?
Most spring onion varieties available are hardy. However, some Asian spring onion varieties require much more warmth. When buying, pay attention to the winter hardiness or use of the respective variety, because non-hardy ones are often only recommended for annual cultivation. More sensitive Asian varieties should either be overwintered in a sheltered greenhouse or poly tunnel, or outdoorsprotected from frost by a protective mulch layer of leaves.
Propagating Spring Onions
In order to propagate spring onions, the plants must be cultivated for at least two years, because inflorescences only develop in the second year. In autumn, select four to five he althy, vigorous plants or a clump from which you would like to receive seed the following year. Since spring onions can interbreed with kitchen onions, a planting distance of 200 meters should be maintained between flowering onions and other types of spring onions. This is the only way to harvest genuine spring onion seeds. Between June and August, the winter hedge bulbs bloom and then form numerous seeds. In our climates, they mature by about the end of August and then easily fall out of the inflorescence. Therefore, you should harvest the seeds when the bracts turn brown. The first black seeds are then already visible. To collect the seeds, put a bag over the seed head, bend it down and then cut off the stalk. Seeds that fall out are caught directly. Indoors at room temperature, the seeds should air dry in a box or something similar, with most of the seeds already falling out. Onion seeds have a shelf life of about one to two years when stored in a dry, dark and cool place.
Tip: If you harvest spring onion seeds yourself, there may be many seeds that are dead, i.e. unable to germinate. These are easy to filter out in a bowl of water as they float to the top. The remaining seeds should then be dried well before storage.
In addition to seed propagation, spring onions can also be propagated by dividing the cane. The winter hedge bulb forms a clump that can be divided in autumn or spring. To divide it, dig it up completely and carefully divide it by hand into appropriately sized sections without damaging the roots. The plants are then placed in a suitable location and watered. A clump should have no fewer than three shoots to ensure it grows back.
The tiered onion (Allium x proliferum or Allium cepa var. viviparum) forms young bulbs instead of flowers. We introduce the curious onion plant and give tips for successful cultivation.