Carrots: Yes. Carrots are nutritional and can be fed alongside leafy greens. Box turtles tend to like brightly colored red, orange and yellow vegetables.[1]
Can Wild Turtles Eat Carrots?
You can put aquatic plants in an aquarium or a pond, and turtles love to eat them. Carrots (tops are fine), squash, and green beans are examples of other vegetables.[2]
Resources
[1]https://www.everythingreptiles.com/what-do-box-turtles-eat/
[2]https://www.turtleholic.com/what-to-feed-turtles-in-a-pond/