Although a mature Ohio buckeye tree is are often found in full sun locations, it grows best in partial to full shade. It's growth rate is moderate averaging 1-1.5' per year. In 3-5 years, a 3 year seedling will grow to about 10'.
Your Ohio buckeye seedling has been container-grown to develop a dense root system that assures easy transplant and survival. It likes a moist, well-drained, rich and deep soil.
Your seedling can be planted immediately or kept in its container until fall when it loses its leaves and the weather is less intensely hot and dry. If you leave it in its container, put it in a shady location and keep it well watered. When planting the tree dig a hole to the same depth as the ball of the tree & mulch above and around the tree base. Fertilize lightly.
Note that the Ohio buckeye tree is about the first tree to sprout leaves in the spring and the first to lose leaves in late summer to early fall. Because of early leaf loss it is sometimes believed to be dying. It's livelihood can easily be verified by observing living buds on its branches and scratching for green beneath its bark. The Ohio buckeye is a very hardy tree, easily surviving winters and usually sprouting from the ground when top growth dies.
The Ohio buckeye is relatively free of diseases except for leaf blotch and leaf scorch and downey mildew. Yellow spots appear on the leaf which can lead too early defoliation. It seldom kills the tree. It can be controlled by spraying with a chemical containing blank or blank.
It prefers shady conditions in its youth but grows in full shade to full sun from youth through maturity.