Fertilizer burn on azaleas?
I have 10 azaleas (don't know variety) in two long balcony planters, all 10 treated the same way. Last month I fertilized them with a 8-6-7 mix which is supposedly for azaleas and gardenias and within a couple of days the 5 azaleas in one planter all had brown leaves which dried up and fell off. I thought maybe I'd watered incorrectly and it is very hot here and they get full afternoon sun (morning shade), but as they began to get new leaves, the new leaves also turn brown and die before they're even grown out. Is this fertilizer burn? If so, how do I correct the soil now? The fertilizer says it must be applied every two weeks throughout the growing season, so I thought by now it would've run through with the watering, but there's been a steady decline and a couple of the plants are nearly dead. There is no sign of any kind of infestation-- no eggs, webs, stickiness, etc., and the other 5 azaleas are not affected. Can somebody help me save these azaleas?