Q.Rosemary root rot
I came across your article on Rosemary root rot searching for potential issues with mine. Plants are brown and losing leaves and condition is spreading. They have been in the ground approximately 5 years and they are watered with 1/2GPH drip emitter for 90 min 2-3x per week. I live in Austin, TX with the very hot summers. I have heavy, clay soil. From your site, it seems I have root rot.
My question – would root rot take a number of years to show? Nothing has changed with the plants since they were put in the ground.
Thanks for your time,
Root rot is a generic term describing an effect -- rotting roots -- caused by any one of a number of pathogens, usually a fungus of some kind, but also possibly bacteria or even viral infection. Just as you may get infected by a "bug," so can your plants. Plants have many ways of fighting infection, but they need to be strong and healthy to do so. Heavy clay soil is not the best for rosemary; it likes good drainage for the long haul. If you want to save your plants, you could try digging them up and replanting elsewhere in a soil amended with sand and organic material. Here's one article that will get you started: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/how-to-improve-clay-soil.htm