Hi - I have 3 rhodedendrons together in my garden and while 2 are flourishing one is failing badly and I really don't know why - would appreciate any insights as clearly they have same light, soil, water etc. I have attached a photo for reference.
Monitor the soil moisture more precisely, especially at a depth of 4 inches/10 cm to confirm it is really getting water there and that it it is not rotting. Ensure it is not getting too much sun and look for any hints of voles and underground pests.
Agree. Dig down and get your fingers right into the middle of the root ball. I have often discovered that the peaty planting mix from the nursery can dehydrate underground and become hydrophobic even after it's been growing if it has gotten even briefly dry.
