Q.One Area Of My Border Is Causing Plants To Die When Planted
This is spot has some morning sun then shade it doesn’t matter what the plant they all wilt then die
Certified GKH Gardening Expert
It sounds like this spot is diseased with something that covers a broad range of plants. This happens when soil remains too wet, typically.
You may need fungicides, or biofungicides to clean up the area. Here are some articles that will help:
https://www.gardeningknowhow.com/special/organic/biofungicide-information.htm
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/garden-how-to/info/what-is-copper-fungicide.htm