How to Grow Parsley

Getting parsley started

Germination is the hard part. UW-Madison notes that parsley seed, like that of other members of the carrot family, has an erratic and low germination rate even under good conditions. Purdue’s germination table gives 40°F as the minimum soil temperature, 50 to 85°F as the useful range and 75°F as the optimum. Cold soil is one reason early outdoor sowings can sit for weeks.

Three things improve your odds:

• Soak the seed overnight before sowing. UW-Madison, Illinois, Colorado State and UF/IFAS all recommend it.
• Start indoors or buy plants. UW-Madison suggests sowing indoors 8 to 10 weeks before the last spring frost; Colorado State says about six weeks before transplanting. NC State notes that parsley is easier to grow from seedlings because the germination period is long, and Texas A&M AgriLife agrees that transplants are easier.
• Mark the row. Illinois suggests sowing a few radish seeds with the parsley. The radishes come up quickly and show where the row is, so you do not hoe out parsley seedlings by mistake.

Sow about ¼ inch deep and keep the seedbed evenly moist until seedlings appear. Weed carefully around them; young parsley grows slowly and is easy to lose among weeds.

Parsley has a taproot and does not move well, so disturb the roots as little as possible when transplanting. Set plants out around or just after the last frost; the dates for your zone above show when that is.

When to plant outdoors

Direct-sowing advice varies. Maryland and Texas A&M AgriLife say to sow in early spring; Colorado State says after frost danger has passed, and UW-Madison says once the soil has warmed. Both work, but seed sown into warmer soil comes up faster.

For a longer harvest, UW-Madison suggests a few sequential plantings through midsummer, and NC State also lists midsummer as a time to sow outdoors. Colorado State advises avoiding excessively hot periods. A fall sowing sometimes overwinters for an early spring harvest, though UW-Madison says second-season leaves do not taste as good.

Regional notes

• Florida and the Gulf Coast: parsley is a cool-season annual. UF/IFAS says to plant in fall and winter; plants grow through winter, then flower and die in late spring. Light afternoon shade can extend their life. NC State notes parsley does better in cool-summer areas and can wilt in the hot, humid Deep South. The Galveston County AgriLife office names October as a planting month.
• Desert Southwest: University of Arizona Extension in Tucson gives October to November and February to April. The Yuma County calendar runs from September to January, with harvest from December to March.
• California: UC Cooperative Extension Sacramento says to sow in spring and fall, and a UC Master Gardener chart recommends full sun with some afternoon shade.
• Colorado and the cold North: Colorado State says parsley generally overwinters in Colorado and gives a second crop the next season, before it goes to seed.

Soil, spacing and care

Unlike many herbs, parsley prefers relatively fertile soil. UW-Madison and Illinois recommend moderately rich, moist, well-drained ground, and it grows in full sun or partial shade.

Spacing recommendations range from 4 to 6 inches (Colorado State) and 6 inches (UF/IFAS, Maryland) to 6 to 12 inches (UW-Madison), 8 to 12 inches (NC State) and 1 foot (UC Sacramento). Colorado State spaces rows 12 to 18 inches apart.

Keep the soil consistently moist. NC State recommends fertilizing outdoor plants twice during the growing season and indoor plants more often.

Parsley grows well in containers, including window boxes and mixed herb pots. A UC Master Gardener chart gives 8 inches as the minimum soil depth. To keep it through winter indoors, Illinois suggests digging plants in fall, potting them up and growing them in bright light in a cool spot, then discarding them in spring and starting new transplants.

Varieties

Parsley comes in three types: curly (var. crispum), flat-leaf or Italian (var. neapolitanum), and Hamburg or root parsley (var. tuberosum), which UF/IFAS describes as having white roots like small parsnips. UW-Madison says flat-leaf types have the stronger flavor and may overwinter better than curly ones.

Illinois Extension names ‘Banquet’ as the standard finely curled variety, ‘Plain Italian Dark Green’ as the standard flat-leaf type, and ‘Argon’ as an improved, upright flat-leaf variety.

Harvesting and storing

Colorado State and the UF/IFAS Osceola County calendar both give 70 to 90 days from seed to harvest. Begin when stems are about 8 inches long (NC State, UC Sacramento). Cut the outer stalks near the base and let the center keep growing; for larger amounts, or at the end of the season, cut the whole plant.

To store fresh parsley, Illinois recommends washing it, letting it drip dry and refrigerating it in a plastic bag; Colorado State suggests standing stems in water in the refrigerator. It also freezes well. On drying, the sources disagree: UW-Madison says the leaves keep their flavor when dried, UC Sacramento says they lose flavor, and UF/IFAS says flavor and color hold if the leaves are dried rapidly. Dig Hamburg parsley roots in late fall.

The second year

Parsley is a biennial. Plants that survive winter send up a flower stalk early in their second season, and Illinois notes that the leaves then turn tough and bitter. Start new plants every year, and treat the flowers of old plants as a bonus: UF/IFAS notes that bees and other pollinators visit them.

Problems

• Slow, patchy germination. Soak seed, keep the bed moist, sow into warmer soil or use transplants.
• Septoria leaf spot. UW-Madison calls it the most common parsley disease. It can be carried on seed, so buy quality seed.
• Aphids. The most common insect pest. Natural predators and parasites often control them; hosing plants off keeps numbers down.
• Black swallowtail caterpillars. Parsley is a host plant. UW-Madison says they are seldom numerous enough to do serious damage and can be handpicked or moved to other carrot-family plants such as fennel or Queen Anne’s lace. UF/IFAS notes that even parsley you never harvest feeds the caterpillars.
• Other pests. NC State also lists stem rot, carrot weevil, flea beetles, leafhoppers and tarnished plant bugs.