Q.What plants can be grown under a buckeye tree?
We have a buckeye tree we want to landscape around
Here are tips for planting under a tree: https://www.gardeningknowhow.com/ornamental/trees/tgen/planting-garden-beneath-trees.htm
Growing from seed may be easier as the developing plant can wind its way around tree roots. Otherwise, consider dividing a plant so each division can fit into a small hole. It is important not to damage tree roots anymore than necessary. Also look to woodland plants and groundcovers. Here is a list of plants that might succeed. Note that you can change list parameters using the tools on the right side of the page. https://www.wildflower.org/plants/combo.php?fromsearch=true&distribution=&habit=habit_herb&duration=&light_shade=1
This trees dense canopy will not let much sunlight in so full shade plants would be best.
You also will need to clean up those buck eyes each fall so plantings that will not be disturbed too much by this task.
This article will help you.
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-6/zone-6-shade-loving-plants.htm