Zwiebel Illustration

Onion "Rouge de Genève"

Jude Jude
29/04/2021 · 5 minutes reading time

Help your April plant grow big and strong.

Here's what's ahead:

Getting Started

Onions may be the most versatile and tasty vegetable that goes misunderstood for the first 15-20 years of nearly every person’s life. But then something changes. A switch flips in the cravings part of our brain, and we realise: wow, onions are one of the best veggies! You can use them in so many different ways, and they always bring something to every dish. That’s why we are excited to include this variety of onion, Rouge de Genève, in our Jack of All Trades Growable Calendar!

The most important information at a glance:

  • Seed depth: 1-2 cm

  • Germination temperature: 15-18 °C

  • Germination time: 21-28 days

  • Start indoors: February-March

  • Plant outdoors: May

  • Plant spacing: 5 cm

  • Location: Sunny

  • Soil: All-purpose

  • Harvest: August-September


Sowing outdoors in a bed:

  • Make grooves in your bed (50 cm apart, 1-2 cm deep).

  • Tear your seed paper into smaller pieces and spread them at a distance of 5 cm in the grooves.

  • Cover the seeds with soil and press down carefully.

  • Moisten the soil regularly until the seedlings begin to germinate.

For sowing in a pot:

  • Choose pots with a depth of about 15 cm.

  • Fill the pots with soil.

  • Make holes in the soil (5 cm apart, 1-2 cm deep).

  • Tear your seed paper in pieces and place them in the holes.

  • Fill the holes with soil and press down lightly.

  • Take care not to soak or pack down the soil too much - this will ensure that the roots can grow deep enough.

  • Keep the soil most until germination.


  • If you aren´t able to keep the planting distance of 5 cm between the individual seeds, you will have to separate the seedlings as soon as the first leaf tubes have developed.

  • Carefully lift out the weaker plants with a pricking stick. You can then plant them somewhere else.

  • Poke a new planting hole with your finger and place the seedlings in the hole.

  • Let some soil trickle into the hole, and water everything.


  • Sunny and windy

  • Soil: sandy and loamy

  • Use all-purpose soil when planting in a pot.

  • Loosen soil and enrich it with compost or organic fertiliser.

  • Choose a location where neither onions more leeks have grown in the last 5 years.

  • Good neighbours: dill, strawberry, cucumber, carrot, kohlrabi, lettuce, tomato, courgette

  • Bad neighbours: bean, pea, cabbage, radish

Zwiebeln kleingeschnitten und ganz im Glas
There aren't many bad ways to eat an onion. Try and think of one, we dare you.


  • Only water when the soil is dry.

  • Avoid waterlogging

  • If the leaves begin to wither, stop watering. This means it is almost time to harvest your veggies.

  • Remove weeds and loosen the soil regularly.

  • You don´t need to add any fertiliser.

Diseases and pests:

  • Downy mildew: Remove infested plants immediately and dispose of them in residual waste.

  • Onion flies: Planting carrots as bed neighbours offers a natural protection against onion flies. You can also add crop protection nets for extra-tight security.

Harvest & Storage

  • When the leaves have almost completely dried up, it is time to harvest your onions.

  • Pull the bulbs out of the ground by the leaves on a sunny day when the soil is dry.

  • Remove any remains of soil from the roots and loose skins, then leave the bulbs with their leaves on the bed for ten days. This allows the outer skin to dry and the onions will last longer.

  • You can cut off the onion greens and use them for cooking as well.

  • Remove the leaves and store the bulbs in a dry, airy and dark place, preferably in baskets or open paper bags. This way they will last until January.

  • Rotate them daily in the beginning, and be sure to keep them out of the fridge. Also be sure not to store them next to potatoes, as both emit gases that interact in such a way that causes both to go bad more quickly.

Zwiebel ernte


These flavourful onions taste amazing, and they complement pretty much any dish. If you want, you can braid onions from the tubes and hang them up. Here's one of our favourite – and one of the easiest – ways to prepare these onions. We'll see how many different uses you can find for them!

Fried Onions

Step 1: Peel the onions, and using a sharp knife slice them thinly, making sure to slice as evenly as possible.

Step 2 (optional): Season your onion slices as you like. Salt and pepper are classic, but there are some other variants you can try to give your fried onions a little kick.

  • Spices! Never be shy to experiment with spices, both with onions as well as with your cooking in general! Garlic and paprika are classics, but who knows, maybe there is a curry-seasoned fried onion recipe yet to be discovered, and your kitchen could be the place for it!

  • Try soaking your onion slices in buttermilk for a half hour, then tossing them in cornstarch before frying. This will give them an extra crispiness when cooked.

Step 2: Over medium heat, prepare about 2 cm of sunflower oil in a large pot or pan. Once the oil is hot, gently drop the onion slices into the device, and allow them to fry until they begin to show some browning and crispiness. This usually takes 2-4 minutes. You will want to stir on occasion, to ensure that the onions are evenly cooked and avoid clumping.