Question: I have an area of evergreen cotoneaster along my front walkway that does not look well. I planted the area 8 years ago with clippings from a friend so I'm not sure what variety it actually is. I can tell you that it is evergreen, arching branches grow to about 5-7ft in length, loads of white flowers appear in spring, red berries in fall and the leaves are a greenish bronze thru out the winter. This area of cotoneaster, spilling over a stone wall, has looked fabulous for years.
This spring, I have notice that almost all of the leaves are all rusty/brown and fairly dry looking. There is minimal (if any) evidence of budding at this point in time. Our winter was no colder than any other, although we did have quite a bit of snow, and we have had quite a bit of rain thru March.
Last spring we had a new front walkway and stone steps put in. Upon completion, I found what appeared to be a very small amount of residual concrete from the actual stone steps sitting at the base of ONE of the plants at the end of the planting bed. That particular plant did suffer somewhat but appeared to have made it thru the summer.
Now they're ALL brownish and look like they're dying....even the ones 7-8 feet away from the stone steps.
Could this be from residual acid run off from the new concrete? If not what else could it be? Is there anything I could do to nurture them back to health?
Answer: Cotoneaster is generally problem free, but there are two diseases that might affect it:
Fire blight causes wilting and blackening of shoots and
the dead leaves hang on the twigs. There is no chemical
control. Prune out infected twigs well below the infected
Scab causes dark areas on the leaves that turn yellow,
then brown, then drop off. No chemical controls are
listed. Rake up and destroy infected leaves.
Aside from these two problems, there may be something going on within the soil that is affecting your plants. I don't think a small amount of concrete dumped in the bed would affect them, but I wonder if the new walkway has changed the drainage in the area? Dig down to see what's there, and make sure that the soil drains quickly (cotoneaster detests wet feet!).
Q&A Library Searching Tips: