It may sound strange, but it really is possible. From leftovers of certain foods or added to other foods. Here are a few.
Potato peels
After peeling potatoes, mix the peels into the soil. And make sure that the peels are always covered with soil. Otherwise, the potatoes will begin to rot. Then water the potatoes, but only if the water is not salty!
Banana peels
These are the same as potatoes. If you have a large freezer and don\’t have any peels to mix in yet, or don\’t know why, feel free to keep them in the freezer. They will darken and soften, but they will be fine in the soil. Also, be aware that if you don\’t keep the lid on, you might get vinegar flies or other pests.
Yeast
Have you used up all the yeast? It is fine. You do not need to store it, but crush it in water. Not in clay like chaff, but in warm water. Let it infuse for two weeks. Then pour water according to the quantity and keep pouring. This method should work especially well for muscats, and they should flower better. Dilution should be done in a ratio of about 1 to 3 to 5 of what you have. It depends on the quantity. About 3 liters per cube.
Coffee powder
When you are done with the coffee, pour the powder over the area to dry. Then put it back in the soil or stir only around potted flowers. Do not overdo it. Just sprinkle it on and then lightly press it into the soil. You can also water it in. Do not use this fertilizer often. Twice a year inside the house. Outside, four times.
Nettles
Some people make nettles into tea, some into spinach, some into salads. Excess is used as fertilizer. The excess nettles are chopped, sprinkled with water, and infused for two weeks. Then drain and mix the remainder into the soil or throw it away if there is no loose soil. The main thing is the leachate, which is diluted and watered again.
There are, of course, many more possibilities, but here are the most well known and therefore proven ones.