How to Grow Flat Leaf Parsley Indoors

Fill a small bowl with water and immerse flat-leaf parsley seeds in it. Allow the seeds to sit in the water for 24 hours to help soften their outer coating and hasten the process of germination. Drain the water from the bowl and spread the seeds on a dry paper towel until dry.

Mix two parts quality potting soil to one part compost or perlite and add to a pot until 2 inches from the top. Because parsley is a deep rooted plant, use a pot at least 8 inches deep to accommodate its tap root. Drill drainage holes through the base of the pot, if necessary, before filling it with potting mix.

Plant the seeds 1/8 inch deep in the potting mix. Water the soil lightly until evenly moist. Place the pot near a southeastern or southern windowsill, or another warm spot exposed to 6 to 8 hours of direct sunlight every day.

Water the pot deeply when the top inch becomes dry to the touch. Spread 2 inches of organic mulch including dried leaves or grass clippings over the soil to keep the roots cool. The seeds usually germinate in 2 to 5 weeks.

Feed the flat-leaf parsley a liquid fertilizer diluted to half its recommended strength every 4 to 6 weeks during the growing season. Avoid overfertilizing the plants, since excess salt buildup damages roots and leaves.

Inspect the foliage and stems of the parsley plants for pests such as aphids and spider mites. Dislodge the pests with a spray of water or dilute 2 tbsp. dishwashing soap in a gallon of water and spray over infestations.