Bonsai require special care and attention to prevent pests and diseases. Fungicides are chemicals that can help to control fungal infections that can damage the leaves, stems, and roots of bonsai. There are different types of fungicides, and each one has its own advantages and disadvantages. Some of the common fungicides for bonsai are: Lime sulfur: This is a broad-spectrum fungicide that can kill various fungi, as well as insects and mites. It can also be used to preserve exposed deadwood and to kill overwintering pests during dormancy. However, it has a strong odor, can stain the bark, and can be toxic to humans and animals if ingested or inhaled. Copper spray: This is a topical fungicide that can prevent and treat fungal diseases such as leaf spot, rust, blight, and mildew. It can also act as a bactericide and an algaecide. However, it can be phytotoxic to some plants, especially if applied in high concentrations or under hot or humid conditions. Chlorothalonil: This is a contact fungicide that can protect bonsai from fungal diseases such as powdery mildew, downy mildew, anthracnose, and botrytis. It can also be used as a dormant spray to prevent fungal spores from germinating. However, it can be harmful to beneficial insects, fish, and wildlife, and it can cause skin and eye irritation in humans.