Without knowing much about the situation, my first two guesses would be under watering and overwatering (crown rot).

It could also be a nasty case of botrytis, which is a fungal infection that affects many plants. Have you had particularly wet or humid weather lately? Is the ground there soggy at all? Does it have good drainage?

If it's under watering, just start watering. If the ground is soggy and/or poorly draining, you'll need to move them pronto.

If it's botrytis, a fungicide could help. You'll also need to remove all affected leaves and throw them away in the garbage. Don't compost them, and be sure to sterilize your garden tools. Fungal infections spread easily. You should probably relocate the plants and soak the ground in fungicide.

The good news with fungal infections is that they typically affect just the leaves of the plant, not the roots. If the problem is fungal, you'll get new growth next year...even on the one in the lower left of the pic that looks really dead right now.

If not, the 2 that are still decent can probably be saved, but I'm afraid the other one is a goner for sure.

This post was edited by flower-frenzy on Wed, Jun 25, 14 at 20:04

You've probably got Terra Nova disease. I'm on my third Berry Smoothie in 3 years. I think it's just a genetically weak plant. They pop up and start looking good in the spring and start to wither away before summer comes...