I use a lot of spring onions in my cocking. And I always throw them away after I cut it down to the white part, ca 10 cm from the roots. But, don't throw it away. You can plant them and they will grow back time after time after you have planted them!
Just do this:
- After you have cut your spring onions, keep 10 cm of the onions from the roots.
- Put the roots in a little glass of water (i use a shot glass), and let the roots grow for 3-4 days in water. Remember to only water the roots!
- Plant them out in a jar with flower soil.
I can promise you, the plants will grow and grow non stop! I have cut mine down maybe 10-12 times, but they still grow out.
Its important that you plant spring onions from your own country! If not, you can destroy your garden, food production and the envioroment.
I live in Norway, and the temperatures during summer is around 15-25 degrees C, and my spring onions love this temperature. Remember to keep the soil moist. They need a daily dose of water. In the winter you can take your spring onions inside.
Its possible to plant sugar peas, salat and other plants with roots in the same procedure. But not every plant is easy to grow, and need more help with growing.