My lemon tree has white stuff on the leaves and limbs. What can I do?

The white substance on your lemon tree could be a sign of pests like mealybugs or powdery mildew. To address this, inspect the tree closely for any visible pests and remove them manually or with a cotton swab dipped in alcohol. You can also spray the tree with a mixture of water and mild soap to help eliminate any infestations. If the issue persists, consider using an appropriate insecticide or fungicide after consulting with a gardening expert.