Plant 2

Plant 3

This is the positioning of the three plants.

Seems perfectly natural. Five weeks of bloom is actually very good. Once the flowers have been pollinated, they turn brown and eventually fall off.

Out of pure curiosity, why the high sides surrounding the new bed?

Yep, this is normal. That is the drawback of these plants that sometimes the dying blooms make you think something is wrong. But it is not. It is just messy looking. You can clean it up by removing the spent blooms if you want to clean up the plant. You can also cut away the bloom heads which will direct more energy into the roots instead of developing seed (which is usually infertile anyway.