What would cause my immature pumpkin to start turning orange? It is a c. pepo, and while it went through a not terrible bout with powdery mildew, I got it under control with milk and Hydrogen peroxide spray. It had set a pumpkin which was growing fine but even for a sugar pie pumpkin, it is quite small. It has now begun to orange. What would cause this? Is this a lack of nutrients? water? I routinely cut back unhealthy leaves (powdery mildew) and feed with kelp/fish emulsion and compost. Any ideas to avoid this from happening again?