Oregano is a perennial herb that can be grown in the garden or in containers. It is commonly used to add flavour to cooked dishes when used fresh or dried. Frequent pruning of oregano plants promote a steady supply of the herb and helps produce full, lush growth. Oregano is moderately winter hardy but requires some protection against the cold. Proper pruning minimises winter damage. Though oregano remains evergreen in some climates, heavy pruning causes new growth that is easily damaged by frost.
Cut back the oregano to within 1 inch of the crown six weeks after planting or after new growth begins in spring. Do not cut into the crown, which is the area where the stems meet the roots. Leave at least one leaf on each stem.
Prune the plant back every six weeks throughout summer. Each pruning supplies foliage for kitchen use and forces new, fuller growth on the plant.
Stop pruning the oregano in September, or eight weeks before the first expected fall frost. New growth forced from the last pruning requires time to mature enough to survive frost.
Trim off single stems for use during winter on evergreen oregano plants. Cut the stem back by up to half its length for daily use. Light pruning in this manner doesn't prompt tender new growth.
Dry the excess foliage after hard pruning in summer. Spread the leaves out in a dry, well-ventilated location for a week. Store the dried leaves in an airtight container. Mulching helps oregano survive winter frost.