|In spring 1996 I planted 2 mountain laurel in a mixed shrub border in a raised bed against my house. They get plenty of water. They get western sun though not full sun as it is filtered by a large tree nearby. They probably get about 3-4 hours of filtered sun in the summer. The leaves have turned brown and crispy. They are at this time full of flower buds and producing new (green) growth and otherwise healthy except for the cripsy brown older growth which predominates the shrub. What's the problem here? How much sun can Kalmias actually take - it is not really alot of strong sun that they get. Everything else in the border is doing quite well.
|There are a few possibilities. It could be wind burn--these plants are susceptible to dessication by drying winter winds. It could also have something to do with your location or soil. Mountain laurel prefer cool, moist, acid, well-drained soil. They will grow in full sun to part shade, so that shouldn't be the problem with yours. You might have your soil tested, and check especially the pH. There are also a few leaf diseases; check the leaves carefully for signs of pests.
Another possibility is salt burn. With this, browning usually occurs on the old leaves first, as opposed to wind burn that generally affects the tender new growth. This is most common in areas with low rainfall, but it can also occur when too much fertilizer has been applied. This excess salt accumulates in the leaf edges, where it kills the tissue. It also interferes with water uptake by the plant. At first this doesn't sound like a planting that is close to the house like yours...but think again... Often there is an overhang that partially covers the shrub. Then often, close to the house, soils have not necessarily been carefully prepared by builders who may have planted these foundation plantings. Finally, with those factors considered, when we see a shrub failing, often our first impulse is to fertilize. In this case it would be the worse thing to do.
Sorry we can't be more specific about your situation. Maybe a local nursery can help you narrow down the possibilities for your locale.