The Right Place For Parsley
Parsley grows best in full sun in cooler areas of the country, but appreciates some afternoon shade in warmer climates. Loosen soil down several inches to accommodate its long taproot. Ideal soil is moderately rich, moist, and well-drained, although plants tolerate poorer soils having less organic matter as long as drainage is adequate. Soil should be mildly acidic (pH 6.0 to 7.0). The pH level influences the plant’s ability to take up nutrients from the soil. To check this, use a soil test kit.
Growing Parsley from Seed Indoors
Parsley seeds germinate reluctantly unless they are exposed to constant moisture for several hours. Soaking the seeds in warm water overnight to soften the seed coat improves germination. A growth inhibitor is leached out of the seeds soaked in water for only 2 hours. Change the water frequently.
Fill flat shallow boxes, peat pots or seed starting equipment with moistened seed starter mix or other soilless medium. Sow seeds about an inch apart in the shallow boxes or two to an individual pot, and cover them with a ¼-inch layer of the moist medium. Keep them evenly moist and maintain soil temperature of about 70° F. Expect sprouts in about 14 days.
To encourage sturdy seedling stems set fluorescent lights two inches above the newly opened leaves. Adjust the lights to maintain this distance above the top leaves of the plants as they grow for 4 to 6 weeks. Then transplant the seedlings outside just after the final frost of the winter when the soil has warmed somewhat.
For more information see Starting_Seedlings
Preparing the Soil for Planting Outdoors
One or two weeks after all danger of frost is past, when the soil has dried out a bit and warmed to at least 50° F, prepare the soil for planting seeds or seedlings.
Loosen the soil down about 8 inches with a trowel or shovel or spade. Remove any stones and debris and turn it over to aerate it. If the soil is thin mix in some organic matter such as peat moss, compost or chopped leaves to improve its drainage and ability to hold moisture.
Break up any large soil clumps, then smooth and level the area. This is a good time to sprinkle some all-purpose slow-acting granular fertilizer on the soil and mix it in.
Starting Parsley Seed Outdoors
To plant in rows, trace a shallow indentation in the soil with a stick or pencil to guide planting. Then sow the seeds by dribbling them through your thumb and forefinger into the indented rows. Plant seeds 1/4 to 1/2 an inch deep. They will sprout in 10 to 14 days.
When sprouts are a few inches tall and showing their first true leaves, thin them by pulling up the crowded and weaker ones, to allow 8 to 10 inches of space to grow between the remaining ones. Depending on the variety, parsley plants will grow to maturity and set seed in about 70 to 90 days. Parsley is a hardy biennial and will often winter over with some protection, and then flower and set seed in their second spring.
Planting Seedlings Outdoors
Parsley is available as seedlings in the spring and early summer in most garden centers. Loosen and smooth the soil in the planting area. Plant on an overcast day or late in the day to minimize transplant stress.
Dig holes in the planting bed about 12 inches apart and about the size of the containers the seedlings are growing in.
Gently pop each seedling from its container by tipping it into your hand while tapping on the bottom of the pot. Set one in each hole and firm the soil over the rootball and around its stem to support it.
Water immediately. If you have added granular fertilizer to the soil, do not feed the plants further at this time. However, adding some plant tonic to the water reduces transplant shock for seedlings. This is an optional step.
Growing Parsley in Containers
Parsley grows easily in a container as long as it gets enough sun. Because it develops a deep tap root, it is best to use a container that is 12 inches deep or deeper. Be sure the container has drainage holes. Fill it with moistened soilless potting mix to within 2 inches of its top.
Plant the parsley seedlings and water them well. Keep them out of bright sun the first day or so while they adjust to the shock of transplanting. Feed container plants once a month with a dilute general purpose liquid fertilizer when you water. Water often to prevent the container plants from drying out during hot summer days. Try starting seeds in late summer and nurture the plants in pots outdoors to get large plants for winter harvest indoors.
Growing Parsley Hydroponically
Parsley can be grown in a hydroponic environment. Start seeds in rock wool cubes or in potting mix just as you would to grow seedlings for transplanting outside. When the seedlings are about 2 to 3 inches tall, set the rock wool cubes in the hydroponic system or wash the potting mix from those rooted in it and place the seedlings in the hydroponic system.
Plants thrive under high intensity lights but will do fine under fluorescent lights. Remember that parsley can get bushy and may need some support in the growing chamber.