Hi, we installed a number of microbiota decussata (Russian Cypress) shrubs on a sunny, well-drained slope. The shrubs did well for the first two years, but this year, (3) are clearly dying. They start looking weak in color, and then fade to a light brown, losing all their green. There is no condition leading to root rot, nor are there clay soils. I was the landscaper for installation, and the slope is built from a decent loam (no standing water). There are (3) other microbiota nearby on the same slope that look fine. I have searched online for diseases and insects that may cause the problem to no avail. Do we replace them, or switch to other stock? Many thanks.
Dying microbiota decussata
I would dig out one complete plant, with all the roots and soil, and take them to your county Cooperative Extension Service for examination and diagnosis.
Examine the main trunks and stems for signs of nibbling by small furry mammals, too.
ViburnumValley, excellent call! We have UMass horticultural lab nearby. Thank you for your suggestion.