After getting off to a great start and ready to bloom, the leaves on one of my B & B are turning black. Noticed a couple with black edges last week. Now, those leaves are all black, with many more leaves that are getting black edges.

This was a new plant this year. The ones that overwintered have no problems. This will be the fourth year of growing B & B, never seen this before.

Could it be too rich of soil??? It is planted in 50% garden compost, in a raised bed, with no fertilizers.

Thanks

Rick