Growing tomatoes in my greenhouse they develop a dull skin. Why is this and can it be cured?
Tomatoes With Dull Skins
Certified GKH Gardening Expert
Sounds like it might be a fungus, possibly powdery or downy mildew. It is not dangerous to people. In a greenhouse, increasing air circulation will help reduce the occurrence of fungus on your plants. Even just an oscillating fan blowing across them will help tremendously.