The completely natural development of a ready-to-harvest kitchen onion requires patience from the gardener: sown onions do not “create” much more in the first year than many beautiful green leaves, because the first vegetation period is not enough for them to develop flowers, and certainly no onions worth mentioning are produced can. Only in the second vegetation period did the onions receive the biological signals in order to develop a flower, while the stem axis in the lower part already thickens into a bulbous, distended onion. In the original onion plant, not just one onion is produced, but many daughter onions next to each other, as can still be seen today with shallots, for example. A part of these daughter onions can then be harvested,
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Garden bulb growth and flower development
Because all of this took too long for humans, a lot has been done in breeding and culture in order to be able to harvest the coveted onion bulbs earlier. Today, onion types are cultivated commercially, which form one large onion and hardly any or no daughter onions and have a late / little tendency to flower. In addition, small onion plants are usually preferred, which can develop an onion of considerable size in one season if they are planted in spring (this is how normal kitchen onions for trade are made). These summer onions can also be grown in mild areas by sowing them in very early spring to be harvested between August and October. This does not make the largest onions, but the sowing should produce onions with a great aroma.
These summer onions can be stored quite well; the later they are harvested, the more ripe the onions and the firmer their consistency. So-called winter onions are also grown, which are, more precisely, onions cultivated for the winter. They are sown in August, ripen in the next season and can then be harvested as early as June. The winter onions are a little juicier and also a little milder, but these “children’s onions” can only be stored for a very short time.
Regardless of how onions are grown: they only develop blossoms for reproduction as adult onions, while at the same time they form daughter onions “on the other side” (in cultivars: one large onion). Since we normally aim to harvest the onions below and not the onion flowers above, the cultivation process should encourage the development of as large an onion as possible. The formation of flowers is disruptive because it costs the plant metabolism strength, which the onion should rather benefit from, so it is prevented as much as possible.
Flowering bulbs can be used multiple times
So much for the disdainful theory of prevented or preventable flowering. But even onion cultivars that are not bred to bloom to the greatest extent are living plants that do not always completely forget the “genetic timetable” of their ancestors. The better you take care of your bulb plants, the better they will grow and the faster they will grow up – with the result that they will be happy to produce one or the other flower.
When that happens, you have several options for dealing with it:
You can remove the flower stem as soon as you realize it is one. When growing onions for the first time, usually only when the stem has already developed a flower; later you will learn to distinguish the much stronger flower stalk from normal onion foliage before flowering. If the flower stalk is removed early, the bulb will continue to grow normally after this flower stalk has been removed and can be harvested normally.
If the flower is already fully developed, you can actually pull out the whole onion plant right away, there will be no “more onion” this season (fully flowering onions no longer form large, round bulbs, but remain small and elongated). Stop the bloom immediately after pulling out, otherwise the bloom will quickly suck all the flavor out of the tuber, use onion + onion leek normally in the kitchen and prepare delicacies with the onion blossom:
Onion flowers can be eaten, such as onion leek and onion bulbs; and they taste pretty good. You make z. For example, you can use simple tomatoes (with oil, salt and pepper) to make a special starter, and decorate salads and spicy soups. Chefs also like to mix the onion blossoms in herb butter – but only when quite a few onions have blossomed in the restaurant’s kitchen garden, because some of the blossoms are already planned differently:
3. Make onions
Connoisseurs are not annoyed when some of their bulbs develop flowers, but leave these flowers on the plant until the seeds are ripe in order to produce their onions themselves:
- Ripe fruit pods slowly dry up until they tear along the midrib, exposing the seeds
- The time has come when the shells of the 5 – 8 mm large seed pods turn brown, usually in July
- Then the harvest can begin; 40 – 80 capsules with several seeds per fruit cluster
- The completely dry flowers are harvested in a bowl on a sunny day, with most of the seeds already loosening from their shell
- The seeds are dried and kept dry over the winter
- Sow in potting soil at the end of February
- Set up growing pots by a sunny window (around 20 ° C during the day, cooler at night)
- After about 10 days, many young bulbs appear, which can be planted in the garden bed if they are strong enough and the soil is warm enough
- If you want to wait for the ice saints in a colder region, move ahead later or plan a stopover in the foil cold frame
- A little too much warmth during rearing should be more beneficial to prevent future flowering:
- In commercial cultivation, cuttings are kept warm to protect against excessive bloom formation
- Temperatures above 6 ° C during the dormant period even destroy an already initiated flower approach
When a large number of onions have flowered, you can put the nutty to peppery tasting onion seeds in a spice grinder and B. on sandwiches or in stews.
In the spice mill, seed coats do not do any harm, but they also do not bring any profit. You can separate the seeds from the husks quite easily by “muddling through” the freshly harvested seeds with your hand in the bowl and then simply blowing into the bowl (outdoors, please). The wafer-thin, light, dry seed coats can be blown away, the somewhat heavier seeds remain (if you blow with sensitivity, “wind from full cheeks” empties the whole bowl).
Freshly cut onions will keep for a while in the vase. This delicate multiple bloom adorns every floristic work of art.
Prevent flower development
In the onion harvest year, the following happens at the same time:
- The roots grow at the bottom of the earth and the stem axis thickens
- Until at some point the bulbous, distended onion that you want to harvest emerges
- If you have chosen old, original onion varieties, a few daughter onions will usually also develop
- Green shoots grow at the top, depending on sowing / pre-cultivation, maybe a strong flower shoot at some point
You don’t want this flowering shoot, at least not on every onion plant, because you cannot harvest real bulbs from flowering onions. So you have to somehow spoil the desire for flowering in the bulbs, the following measures are suggested:
- Prepare the onion bed in the autumn before cultivation by working well-ripened compost into the soil
- After sticking onions, keep them tight within the required good nutrient supply (high eater)
- So if possible, only carefully re-fertilize with organic fertilizer such as horn meal
- Rapidly available mineral fertilizers are difficult to dose, too little makes onions shoot, too much leads to a lot of limp green
- For mulching, choose a meager mulch of leaves rather than tasty compost, which animates vigorous onions to bloom
- Cut away any flower buds as soon as possible
- If a particular variety continues to bloom excessively, you are just too comfortable with those bulbs
- So choose another variety (or switch to an onion grower)
When bulb plants bloom, plants that have been greatly influenced by breeding will remember their true nature. So not a broken leg, but rather a compliment to the good care. If you can’t stop flower development in time, there are some things you can do with the onion flowers, such as: B. grow new onion plants.