Common onion problems include poor bulb development, yellowing leaves, fungal diseases, and pests such as onion maggots and thrips. Overwatering and poor drainage can encourage root and bulb rot, while overcrowding can reduce air circulation. Weeds can also compete with onions for nutrients, water, and sunlight. Check plants regularly for discoloration, damaged leaves, or insects. Providing suitable spacing, well-draining soil, adequate sunlight, and careful watering can prevent many problems and support healthier onion growth. know more about how to grow onions