Hydrangeas

Question

Can Annabelle Hydrangeas grow near a black walnut tree?

Answer 1

Hydrangea are sensitive to a Black Walnuts toxicity.
I would not advise planting this shrub near your tree.
These links have more information.

http://www.mortonarb.org/trees-plants/tree-and-plant-advice/horticulture-care/plants-tolerant-black-walnut-toxicity
https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/growing-hydrangeas-hydrangea-care-guide.htm
https://www.gardeningknowhow.com/garden-how-to/info/allelopathic-plants.htm