All the postharvest principles that apply to leafy green tissues apply to the handling of fresh herbs.
Temperature is the single most important factor in maintaining quality after harvest.
Optimum postharvest temperature for fresh thyme, oregano, rosemary, mints, sage, parsley, cilantro, savory, marjoram, dill, and tarragon is 32 F. A shelf life of 3 to 4 weeks can be achieved at this temperature. With a temperature of 41 F, a minimum shelf life of 2 to 3 weeks can be expected. If herbs are harvested early in the morning, the need for cooling is minimized. If harvested later, the appropriate cooling method depends on the type of herb. Most respond favorably to room and forced air cooling.