Q.Nellie Stevens Holly
Good Day! We have 4 Nellie Stevens holly trees. They are flourishing. Two years old. But they always produce berries that are green and never turn red. They do produce little flowers. Why is this?

Certified GKH Gardening Expert
Are you fertilizing the trees with a balanced fertilizer such as 10-10-10? They probably just are not mature enough yet. Give them time and they will turn red. Make sure your plants are getting enough sun, water, and fertilizer.
https://www.gardeningknowhow.com/ornamental/shrubs/holly/nellie-stevens-holly-care.htm
https://www.gardeningknowhow.com/ornamental/shrubs/holly/when-does-holly-bloom-fruit.htm