Young rhododendron with yellow and brown leaves

Question

I have a fairly young rhododendron (at least two years). We planted it in the spring. For the past 2-3 months the leaves have slowly been yellowing and turning brown in spots.

The soil is acidic, but to what degree I am not sure. I have not fertilized beyond mulch and a bit of old coffee grounds. The plant gets partial sun (mostly hot afternoon sun), and it hasn't rained for about 6 weeks although I water it every other evening.

Is this a "wait and see" type of problem, or is there something I can do to make it healthier?

Answer 1

Use Sequestered Iron. Do it slightly on the weak side and follow the instructions. Some products say do it every week at certain times of the year or apply once a month, it depends on what product you go for, powder or liquid feed. Don't go for a foliar feed, you might burn the leaves further! Try to avoid getting the leaves wet when you water especially on sunny days. Do it in the evening.

Also I would clear up any dead leaves found and destroy them. Don't compost them, rhody leaves have toxins in them that prohibit other plants growing around them so they're not good for compost. They also have an extensive list of possible fungal problems too.

On the top of things it looks like nothing more than scorch, but the yellowing says something different, perhaps a micro nutrient deficiency, some type of magnesium/metallic problem.