Fall planting is recommended, but that depends on having a healthy plant at the time. You can plant in summer if you provide adequate watering and some temporary shade. Another option is to pot this into a larger pot and keep shaded from the hottest sun. The direct sun heats up a small black pot sometimes beyond what roots can handle.
Before you transplant or repot it, examine the root ball. Healthy roots aren’t black, and smell Earthy, not moldy. If the plant seems very root bound or unhealthy, consider taking to your place of purchase to ask about returns or guarantees.
This OSU publication about planting tree techniques works for woody shrubs. Current recommendations include planting using only native soil in planting hole.
I just found this WSU publication about planting, including illustrations about healthy roots.