Parsley

prezzemolo

Common name
Parsley

Scientific name
Petroselinum crispum Hoffm (sin. P. hortense)

Botanical family
Apiaceae (sin. Umbelliferae)

History and origins

Native to the Mediterranean area.
It was known by ancient Romans as a medicinal plant. In the past, it was also used as an emmenagogue and an abortifacient because of apiol (one of its main components) which contracts the smooth muscles of the intestine, bladder and uterus.
Towards 1500, it began to be considered as a food source, first in Italy, and then in England and Germany.

Nutritional characteristics

Parsley contains several volatile oils (myristicin, limonene, eugenol, alpha-thujene) and flavonoids (apigenin, apin, luteolin…) with chemo-protective effects on the human body.
Various studies highlight the biological activity of parsley:
– it contains large quantities of apigenin which has been found to have a strong antitumoral activity as it inhibits the formation of new blood vessels that feed cancerous growths (especially in breast tumors);
– myristicin has shown analogous results with lung tumor formation;
– it is a source of phytoactive compounds, mainly carotenoids (pro-vitamin A or beta-carotene) with well-known protective effects from atherosclerosis, colon cancer, diabetes, asthma…;
– it has a high vitamin C content with its ensuing anti-inflammatory properties (e.g. it hinders osteoarthritis and rheumatoid arthritis), a high vitamin K content (which is necessary for the synthesis of osteocalcin, a protein that strengthens bone composition), and sphingolipids (the fats needed to maintain the myelin sheath around nerves);
– like mint, sage and thyme, it has a strong antimutagen effect thanks to its antioxidant properties and the capacity of phenolic compounds (especially luteolin) to inhibit DNA damage caused by free radicals;
– the aqueous extracts of its seeds increase diuresis, and therefore help reduce blood pressure (hypotensive action); its diuretic and sudorific properties are mainly due to apioside, a flavonic substance;
– in ancient times, parsley was also used as an emmenagogue and an abortifacient due to its apiol content which induces the contraction of smooth muscles of the intestine, bladder and uterus. Because of its abortifacient effect, pregnant women must avoid coonsuming excessive quantities of parsley.

Diffusion and importance

In Italy, about 1,000 ha is cultivated in open fields and 140 ha in greenhouses (ISTAT data, 2011).

Botanical characteristics

Biologic type: parsley is an herbaceous plant, biologically biennal, but annual in cultivation.

Root: taproot.

Leaves:pinnatisect, some peltate, lobate and triangular in outline, some linear and whole with long stalks.

Inflorescence: the transition from the vegetative to the reproductive phase is regulated by the photoperiod (long-day species). A flowering stem (erect, branched, at most 1.0-1.5 m in height) leads to umbels composed of small, hermaphrodite flowers, with greenish petals. Cross-fertilization (allogamous species) with mainly entomophilous pollination. Flowering and seed ripening are progressive.

Fruit: it is a diachene (schizocarp), glabrous, oblong, spherical. The single achene (“seed”) has an oblong shape, yellow- brown color, one flattened side and one convex side that is characterized, as with other Umbellifers, by well-defined ribbing; it is similar to the carrot fruit, but larger (1,000 seeds weigh 1.5-2 g).

Climate and soil requirements

Climate
Parsley is a species that prefers warm climates; it has low resistance to severe and prolonged cold. Germination is a very delicate and difficult phase: at 10-12° C it takes about 30 days; at 22-24° C, it takes only about 15 days. Its thermal requirements are listed in the table.
High water requirements.

esigenze termiche del prezzemolo

Soil
Parsley can adapt to any kind of soil if it is rich, loose and drains well; it prefers a pH of 6-6.5. The position of parsley in rotations varies, but it must not be planted in soil where parsley or other Umbellifers (celery, fennel, carrot…) have grown for at least 2-3 years. In organic agriculture, it is often used as a companion crop for tomato, asparagus and corn to attract parasitic hymenoptera of harmful moth larvae.

Varieties and/or commercial types

This species includes several botanical varieties (corresponding to several cultivated types):
var. typicum : common parsley, with small leaves

common parsley
Common parsley

var. latifolium : giant parsley, a tall and strong plant; its leaves have long stalks and large lobes, similar to celery leaves

giant parsley
Giant parsley

var. crispum : curly parsley, with ruffling foliar lobes, not very aromatic (used mainly as garnish)

curly parsley
Curly parsley

var. tuberosum: root parsley, with large and fleshy taproot

Fundamentals of cultivation practices

Parsley is usually sown from January to September, but it can also be transplanted using seedlings with root ball.
Sowing can be broadcast (about 1-2 g of seed/m2) or in rows 20-30 cm apart (0.2-0.3 g of seed/linear meter). Seeds must be very near the soil surface (5 mm); to favor germination and emergence, soil can be covered with non-woven fabric. After emerging, plants must be thinned so that they are 15 cm apart.
Transplanting is done in rows that are 25-30 cm apart; plants should be planted at a 15-20 cm distance from one another in each row.

Harvesting

Parsley is harvested about 70-80 days after sowing. Harvesting is progressive and starts when leaves are about 20 cm long, although this varies according to the different leaf size and stalk length of different cultivars. After harvesting, parsley will resprout and is once again ready to be harvested after 20-30 days; with good cultivation practices, it is possible to cut it up to 5 times, for a yield of about 1.5-2.0 kg/m2.