Trim just the leaves off of smaller (less developed) annual herb plants. Trim whole stems from larger annual herb plants that are showing strong growth.
Trim down the parts of the herb plant that have reached their maximum height. Doing so will allow sunlight to reach the parts of the plant that are still growing.
Trim parsley and chive plants at their bases, leaving an inch or two above the soil. After trimming, you should notice new growth within a week.
Trim the tops off of perennial herbs (such as sage, rosemary and tarragon) every week during the summer season. This will encourage new growth, developing a more full plant with stronger roots over time.
Trim all dead stems and leaves from both annual and perennial herb plants.