I've had a Greek Oregano (Origanum vulgare) plant in a terra cotta pot for most of the Spring and Summer. It was sitting out in the backyard. It seemed to be doing well. During the long hot dry stretch we had, and because it's in a pot rather than in the ground, I made sure to feel the soil and water it whenever it felt dry. Sometimes that was every two or three days. I went on vacation for a week (July 6 - 13) so gave it some water the day before I left. Now it is dry and brittle. Seems to be dead. Did I give it too much water before I left? Did it die of too little water for the week I was gone? (It was watered while I was gone.) Could it have been killed by insects? Maybe something in the soil? Losing this plant really bums me out; I thought I was doing everything right for it.
I'd be suspecting overwatering causing the roots to rot. It likes dry soil, and isn't well adapted to wet. See if it resprouts from the base; if it doesn't, then the roots are as I fear dead.
