You don't need fresh organic fertilizer on the bed to grow onions successfully. Soil fertilized in autumn is better. You should also be a little more cautious when adding mineral fertilizer. The spicy tuber will thank you.
How should onions be fertilized?
Old fertilized soil and a cautious application of mineral fertilizer are best suited to growing onions. Fresh organic fertilizer should be incorporated in the fall. During growth, phosphorus and potassium fertilizers can be used, but are not necessary.
The onion is a low to medium feeder and thrives best on old fertilized soil that should not be too moist and heavy, also as a second crop after peas, spinach or lamb's lettuce. As a rule, the normally tilled soil of an evenly cultivated home garden is sufficient.
During the growing season you can fertilize with phosphorus and potassium fertilizers. However, this is not absolutely necessary. Occasionally you hear about a recommendation to add wood ash, but this is more suitable for preventing onion fly infestation.
Organic fertilizer
If fresh manure or compost is used as fertilizer, it should be incorporated into the soil in autumn for spring planting. The compost can rot over the winter and the soil can settle well, so that it becomes finely crumbly and loose.
It doesn't matter whether the onion sets are planted at the end of March or the beginning of April or the onion seeds are spread into the beds. Both do not need freshly fertilized soil for he althy growth. Under certain circumstances, this could even promote undesirable onion fly infestation.
Mineral fertilizer
Here, too, the plants react to nitrogen over-fertilization with delayed growth or poor maturation of the tuber. Instead, only the onion leek thrives while the bulb softens and the peel peels off. This also jeopardizes the storage life of the onion.
Tips & Tricks
Don't throw in the towel straight away if the onion harvest doesn't work out as desired. Often it can also be due to a rainy summer. Because the onions ripen best in dry mid-summer weather. It will definitely work next summer.
