Can I propagate giant onions myself?

Can I propagate giant onions myself?

What methods of propagation are there for giant onions?

Allium giganteum, the giant onion can be propagated by dividing the onions or separating daughter onions or by sowing. Both methods are easy to implement and, in most cases, are successful.

also read

  • How to care for your giant onion - tips and tricks
  • Planting giant onion (bot. Allium giganteum) - tips and tricks
  • Propagate the globular leek via seeds and bulbs

Where do I get the seeds from?

Of course, you can also purchase various seeds for giant onion in stores, but if you have your own giant onion, then just use its seeds. To do this, leave the withered inflorescences until the seeds inside have turned black. Now they are ripe for harvest and speedy sowing. Store the seeds only briefly, but then in a dry and dark place.

Sow the giant onion

Before the seeds of your giant leek can germinate, they need a certain amount of cold, because they are so-called cold germs. Temperatures should be around freezing for at least a few days, if necessary in the freezer or refrigerator.

If you sow your giant onion outdoors immediately after harvesting, the seeds will germinate in the next spring. However, it can also be grown on the window sill after cooling. Keep the seeds evenly moist.

Propagation by bulbs

The giant leek practically does the propagation through brood onions all by itself. In addition to the main onion, small daughter onions or brood onions grow over the years. If these are sufficiently developed, they can be transplanted. It's best to dig up your spring onions in the fall. Separate the largest daughter bulbs and put them back in the ground at a suitable location.

The essentials in brief:

  • Propagation possible by sowing and setting bulbs
  • Only harvest seeds when they have turned black
  • Sow immediately after harvest
  • if storage is necessary: ​​dark and dry
  • Mix the potting soil with quartz sand (€ 14.90 at Amazon *)
  • Cold germ
  • Keep the substrate and seeds moist
  • Plant brood bulbs in autumn
  • Avoid waterlogging!


The giant onion can be propagated quite easily and even takes on this task itself with the formation of daughter onions.