It is best to plant in spring or fall. With summer planting, you really have to be careful with watering. It’s easy to either overwater or underwater. At least, it is for me! The brown flowers are a sign of stress. Try to spread out how often you water. And, hope for a really good rainstorm and cooler temperatures. That will help it get settled in. Other than the summer planting, you have done everything else well. I’m sure it will turn out fine. Next up will be getting it ready for winter. For tips on winter prep, check out my video.Thanks for writing!