red on my plum tree leaves

Question

Plum tree has reddish leaves and is drooping.

Answer 1

There are a number of possible reasons, cultural and pathogenic. Reddish leaves can indicate nutrient imbalance, or diseases such as peach leaf curl (can infect plums also) and plum pocket. These articles have more information: https://www.gardeningknowhow.com/edible/fruits/plum/plum-tree-dropping-leaves.htm
http://web.aces.uiuc.edu/vista/pdf_pubs/805.PDF
The surest way to diagnose the problem and treat it correctly is to take some leaf, branch, and soil samples to the county extension service. This link will help you locate the nearest one: https://www.gardeningknowhow.com/garden-how-to/info/what-is-extension-service.htm