Last fall I got two elderberry plants from the Seattle native plant sale... one red, one blue. They over-wintered in their one-gallon pots just fine. Come fall they grew new leaves and I transplanted them into my yard around late Feb. They both did well until around May, when the red elderberry died in a very, very short time. All of the leaves drooped down and sagged in less than 1 day. It looks like the one in the picture I attached. I water it more than enough! I soaked it for the first two or three days... didn't help. Then I moved it to a shadier spot... that didn't help. It was completely dead within 5 or 6 days.

In the mean time, my blue elderberry was doing great. I shot out two big sets of flowers that are just last week starting to turn into berries. Then two days ago the same exact thing happened. It wilted and drooped down in just a few hours. Literally, was great in the morning, then about 10 hours later it was completely limp and droopy.

I dug it up last night after work. Sprayed it down completely to the bare roots. Mixed up the compost and soil thoroughly where it was planted. Added a little rooting hormone to the hole and to the roots, and then replanted it.

I hope that helps, but I'm at a loss. I found no bugs on the roots. There's no damage to the foliage. The roots look fairly clean and healthy. I just don't get it. I water it plenty. I've had no issues with all the other native plants I have. I have another 40 or so native berries planted... from huckleberry to thimbleberry. All planted in compost I made and a layer of leaf/wood chip mulch on top. The soil is acidic, which they should love. It's planted in a spot where it gets sun from morning until around 4ish.

All I can think of is that there's some microbe or bacteria I can't see. Please let me know if you have any suggestions.