Common parsley, Petroselinium crispum, a member of the carrot family (Apiaceae), is well known for its use as a garnish or as a flavoring in many dishes and salads. The curly varieties also make a nice addition to most gardens, planted with other herbaceous plants or used in a border. Native to the Mediterranean area, parsley has a biennial life cycle, but is usually grown as an annual in our region, because the plants often die during cold winters.
As with most herbs, parsley does best in a sunny area which receives direct light for 6-8 hours a day, although it can tolerate some light shade. Plants will be more productive if grown in well drained soil that is fairly rich in organic matter, with a pH range of 6.0-7.0.
Although germination is notoriously slow, seed propagation is the easiest way to start plants. The rate of germination is dependent upon seed freshness, ranging from 2-5 weeks. To help hasten the process, soak the seeds in warm water for up to twenty-four hours prior to planting.
Seeds can be started indoors in the late winter approximately 6-8 weeks ahead of the last frost date. Seeds can also be sown directly in the ground where they are to be grown, after danger of spring frosts has passed. Cover seeds with 1/8 inch of soil, and keep them moist. Since germination is so slow, it's a good idea to mark the rows. Emerging seedlings will appear almost grass-like, with two narrow seed leaves opposite each other. Thin or transplant seedlings when they are 2-3 inches high. Final spacing should be 10-12 inches apart.
Do not allow the plants to dry out completely between waterings in the garden. Water deeply at least once a week to insure the roots are receiving enough moisture during the growing season. A light mulch of ground up leaves or grass clippings will help retain moisture and keep weeds to a minimum.
Fertilize plants in garden beds once or twice during the growing season, using a 5-10-5 commercial fertilizer at a rate of 3 oz per 10 feet of row. Use a liquid fertilizer at one half the label recommended strength every 3-4 weeks for container grown plants outside and every 4-6 weeks for parsley grown indoors.
Parsley is an easy herb to grow indoors as long as it has a bright location and holes in the bottom of the pot to insure good drainage. The plants may be a bit spindly when grown indoors; this is due to lower light levels.
Harvest leafy stalk-like herbs such as parsley by snipping off the stalks close to the ground, beginning with the outside stalks. New growth will be encouraged throughout the growing season if pruned in this fashion. If just the tops are cut off and the leaf stalks remain, the plant will be less productive.
Fresh parsley has the best quality. Although it can be dried or frozen, much flavor is lost. The plants remain green and productive into fall and can handle light frosts. Leave the plants in place after the foliage has been killed by frost, and they may resprout in spring, depending on winter conditions. Then you may again harvest fresh parsley until the plant sends up a seed stalk and dies, having completed its biennial lifecycle. However, this second year parsley will be more bitter than the previous season’s harvest.
Dry the leaves by spreading them on a screen or hanging them upside down in bunches in a warm, well-ventilated room out of direct light. For quick drying, dry the leaves in a slow oven at 100-110°F for just a few minutes. Store the dried leaves ground or whole in an air-tight container away from heat sources or bright light. Fresh parsley can also be frozen in small bags in the freezer. Parsley preserved by either method should be used within a year's time.
The most common variety is common or curly parsley Petroselinium crispum. These curly types are quite versatile, typically growing 8-14 inches tall, forming dense clumps which are great for borders, interplanting in the garden beds, and indoor or outdoor containers.
Italian flat-leaf parsley, P. neapolitanum is another popular variety. This plant can grow quite tall (2-3 ft) and is more gangly in habit. The flat serrated leaves have a much stronger and sweeter flavor than the other varieties, making it more desirable for cooking.
Hamburg parsley, P. tuberosum, is mainly grown for its white, fleshy, parsnip-like roots, used in flavoring soups. Tall, fern-like leaves make up the foliage.
Japanese parsley, Cryptotaenia japonica, resembles the Italian parsley but is not commonly grown. It has a more bitter taste and is sometimes used in Asian cooking.