Tomato blossoms turning brown - no tomatoes

by Karen
(Monroe, CT USA)

I have some brandywine and 2 unidentified varieties of heirloom tomatoes (the local grower didn't know their variety) as well as some cherries that reseeed yearly. One of these unidentified heirlooms is not producing any tomatoes. There are about 25 blossoms but they brown out and just cling to the plant.

Some of the brown blossoms have been on the plant since the 4th of July. The plant is about 5 feet high and about 3 feet wide .

The tomatoes are about 3 feet away from each other there are holly hocks growing in between the plants. The others are doing great.

The leaves look great as does the stem. I don't see any pests. Any ideas?