Ornamental onions with their more or less large balls of flowers enchant many a garden in early summer. The plants are not very demanding and can easily be propagated by yourself.

In a nutshell

  • Ornamental onions are perennial and hardy
  • Leek plants love a sunny to partially shaded place
  • Propagation by seeds possible
  • Allium likes to propagate by self-seeding
  • very easy is the propagation by onions

Eye-catcher in early summer

There are over 800 different types of ornamental onions. With its colored flower balls, which are made up of individual star-shaped flowers, it sets colorful accents in every garden. The color palette ranges from white to yellow, pink to violet shades. Depending on the variety, the bulbous plants reach heights of growth of 10 cm to 150 cm. Allium is perennial and hardy. The bulbs overwinter in the ground. In addition, Allium can also be propagated very well by yourself. There are two different options. More on that below.

Notice: Allium not only magically attracts butterflies and bees, but once planted, it also reliably repels voles.

Generative propagation

Allium can be propagated by sowing seeds. This is available in specialist shops, but you can also win it yourself. To do this, simply do not cut off the faded flower balls. It then forms a capsule fruit with seeds inside. When ripe, this can easily be shaken out of the capsule and collected. The small and irregularly shaped seeds are ripe when they appear black and shiny. Small plants can then be grown from this. If it is not used immediately, it must be stored in a cool, dark and dry place. Before we start sowing, it is interesting to know that the ornamental onion is a cold germinator. He needs cold so that the seed can germinate. There are now two different options for sowing.

Instructions for direct sowing

The easiest way is direct sowing in the bed outdoors. The best time for this is the fall immediately after harvesting the seeds. Over the winter, the seed receives a decent cold stimulus and then begins to germinate in the following spring. In order to be able to grow small plants, some preparations must be made beforehand:

  • choose a sunny, warm, sheltered spot
  • Soil must be rich in nutrients, if possible sandy, finely crumbly
  • Prepare the bed accordingly
  • Thoroughly loosen the soil
  • enrich with compost
  • Make seed furrows 1 cm deep
  • insert 1 to 2 seeds at a distance of 10 to 15 cm
  • Cover grooves with 1 cm soil
  • press lightly with your hand
  • water lightly
  • Use watering can with sprinkler
  • Keep the site weed free

It is advisable to protect the sown seed with a net from bird damage.

Tip: However, growing ornamental onions from seeds only makes sense for pure species. Otherwise, the characteristics of the mother plant cannot match those of the young plants.

Preculture in the house

In addition to direct sowing, it can also be cultivated on the windowsill. However, a cold shock is also necessary here beforehand. The seed must be stored for a few days in the refrigerator or freezer at temperatures around freezing point. The procedure is as follows

Source: User:Pipi69e, Allium ursinum seedlings1, Edited by Plantopedia, CC0 1.0
  • Mix seeds with fine sand
  • place in freezer bag and seal tightly
  • then store in the refrigerator at 0 to 4 °C
  • Storage for seven to eight weeks
  • then fill the seed pots with seed soil
  • mix in some quartz sand if necessary
  • two seeds per pot
  • Plant 1 cm deep in the ground
  • cover with soil and press down lightly
  • moisten slightly with a hand spray bottle
  • Always keep the substrate moist, not wet
  • no waterlogging
  • Place in semi-shade on the windowsill
  • leave the strongest seedling after emergence
  • remove the rest

Fertilization is possible for the first time when the young ornamental onion plants have four to five cotyledons. A liquid fertilizer can be used. This is simply administered with the irrigation water. The young plants can then be planted outdoors at the end of April/beginning of May. It is not absolutely necessary to sow the seed immediately after the harvest, neither with direct sowing nor with pre-cultivation on the windowsill. It can also be sown in the following spring from March to April. However, good storage is then necessary:

  • dark, cool and dry
  • in the refrigerator at 0 to 4 °C
  • this preserves the ability to germinate

Disadvantages of generative propagation

Propagation by seed is quite expensive. It takes a lot of patience. Germination can take up to three months or longer. Sometimes there is none at all. It can take a long time for seeds to develop into large plants with strong bulbs. The first flowers usually only appear after two to three years.

Notice: Ornamental onions can also self-seed very well. To do this, only withered inflorescences must remain. The seed falls to the ground, overwinters there, and then in the spring it begins to germinate.

Propagating Allium vegetatively

It makes sense to use this method if the existing stocks are too dense and the leek plants interfere with each other. It is also the easiest way to propagate Allium and it always works. Over the years, various daughter or brood bulbs form on the mother bulb. These can be carefully separated from the mother bulb in autumn and transplanted to a suitable place by November. location requirements

Source: Glaoadare, Oignon rosé de roscoffP1000686, Edited by Plantopedia, CC BY 3.0
  • sunny to semi-shady
  • Soil permeable, loose, nutritious and sandy
  • Loosen up heavy and damp soils with sand

Once the question of the location has been clarified, the digging up and replanting can begin. Here is a short guide:

  • Cut the plant down to the ground
  • Carefully lift out the onions with a spade
  • Carefully separate the daughter onions from the mother onion
  • Dig a plant pit
  • should be twice to three times the height of onions
  • at least 10 to 15 cm deep
  • Place a 2 to 3 cm layer of sand or gravel in the planting hole for drainage
  • mix in a handful of horn shavings
  • Place the bulbs in the planting pit with the tip upwards
  • Mix a third of the excavated soil with compost
  • Fill in the planting hole
  • Press the soil down lightly and water well
  • Planting distance 15 to 25 cm depending on the variety
  • Mark the planting site with a wooden stick

Tip: The onions should be plump, white and firm.

frequently asked Questions

When is the best time to plant the bulbs?

Whether mother or daughter bulbs, they should be planted between September and November. They still have enough time before winter to take root in the soil that is still warm in summer.

What happens if the bulb is planted upside down?

The tip of the onion is often a bit difficult to see. She is hidden under coverings of shells. So please examine the onion carefully. If the tip is now placed down in the planting hole, the Allium will not develop flowers in the following year.

Do spring onions planted in autumn need winter protection?

Normally the allium plant hardy. However, freshly planted spring onions should receive a light winter protection from leaves, brushwood or compost in the year of planting. After the second year, protection is no longer necessary.

Category:

Garden plants