Mix potting soil with organic matter such as compost, leaf mulch or rotted animal manure. If growing outdoors, make sure the bed is dug over well to remove clumps. Fill indoor pots to just about full and but don’t pack it down to ensure good drainage.
Plant seeds in April or after the last frost in colder climates. Sow them about 1/2 inch deep in the soil and about 6 inches apart. When growing indoors, plant seeds 1/2 inch deep in a small pot in March and then transplant the seedlings to a 12-inch-diameter pot around May.
Water the soil when it feels dry to touch, and only so that it is moist, not soaked. Oregano is a Mediterranean plant used to dry conditions, so water only as the soil begins to dry out.
Feed oregano no more than once or twice during the growing season with an organic mulch such as seaweed or compost.
Allow seedlings to grow for about two to three weeks and then thin them so that they are about 12 inches apart. This will provide them enough room to grow to full size.
Harvest leaves in July, before the flowers appear. Remove flower heads before they open to prevent bitter-tasting leaves.
Prepare the soil by mixing it with plenty of organic matter such as compost or well-rotted manure. Select an area with full sun or partial shade.
Prepare plants for outdoor growing by sowing seeds in pots indoors in March if you're planting outdoors in regions where fall and winter months are cold. Plant about four to five seeds per pot. Parsley takes a few weeks to germinate because it requires high temperatures. For this reason, it should be grown indoors in a sunny, warm room until it is established. Thin seedlings down to one per pot after about three weeks.
Harden the plants during the first week after germination by taking them outside during the warm daylight hours and bringing them indoors at night.
Leave plants out all night in their pots for about five nights before transplanting outside. Make sure the plants are at least 3 inches tall before transplanting.
Feed parsley monthly with an organic liquid fertilizer and keep the soil free of weeds.
Water regularly so that the soil is consistently moist but not soaked. Increase watering during dry periods. If growing indoors, you may have to water more frequently as the soil tends to dry out faster than outside soils.
Cut leaves to be harvested with scissors once your parsley is established, but don’t remove all of the leaves from a single plant because this will impede growth.