How to Grow Parsley
To grow parsley, start by soaking some parsley seeds in warm, soapy water for an hour and then transferring them to a bowl of clean warm water to sit overnight. Then, dry the seeds and plant them outdoors or in an indoor pot. Regardless of where you plant them, make sure your parsley is in a spot that gets at least partial sun during the day. Water your parsley deeply once a week and pull up any weeds that sprout. Once it has sets of 3 leaves, your parsley is ready to be harvested.
Choose a type of parsley. Parsley comes in two general varieties: curly leaf and flat leaf (also known as Italian parsley). Flat leaf parsley tends to have a slightly stronger flavor than that of curly-leaf parsley, but both types are relatively mild. You will also need to decide if you want to grow your parsley from seed, or if you will grow the plant from a start/potted version. Select a location. Parsley works well in any garden or pot, as it doesn't have strict growing conditions under which it thrives. Choose an area that gets at least partial sunlight, either in its own plot or between other garden plants. If you decide to pot your parsley, place it on a windowsill that gets morning sunlight, such as on an eastern-facing windowsill. Prepare the soil. Soil that is relatively loose, full of compost/nutrients, and has a pH level between 6 and 7 is perfect for parsley. Test the pH of the soil, and incorporate peat moss into it if the soil is too basic. To create the perfect soil mixture, mix 50% potting soil with 50% compost for nutrients. This will create a light and airy soil mixture that will make it easier for the small root-system of the parsley to attach itself to. Soak the seeds in soapy water. Fill a large cup or bowl with warm (not hot) water. Add a splash of dish soap, and stir the mixture to help it to dissolve. Place all of your parsley seeds into the mixture and allow them to soak for one hour. The heat of the water and the dish soap will help to break down the notoriously tough outer casing of the parsley seeds, helping them to grow faster than they would without soaking. Rinse and move the seeds to another bowl of water. Using a small strainer, pour the soapy water out and run the seeds under lukewarm water. This should remove any traces of the soap, and prepare them for the next step. Fill a bowl with very warm water (near 105 degrees Fahrenheit) and place the seeds in the water. Leave these to soak overnight to continue the germination process. Dry the seeds. After 24 hours soaking in the water, remove the seeds with a strainer and lay them out on a piece of wax paper to dry. When they have been fully dried, they are ready to be planted. Start your seeds indoors. If you want to speed up your planting time even further, you can plant your parsley ahead of time in small containers and move them to their final destination after sprouting. 6-12 weeks prior to the last frost before Spring, plant your parsley seeds into small containers and water them daily. This should give them enough time to begin sprouting, increasing their time to full bloom when planted outdoors or in a larger pot. Plant at the right time. Wait until all possibility of frost has passed and sow the seeds directly in the garden if you did not start them indoors. Typically, the seeds should be planted at the very beginning of Spring, around March or April. Dig your holes/rows. Using a small trowel, make the rows in your garden approximately 10 to 12 inches (25.4 to 30.5 cm) apart and long enough so that the seeds can be sewn in 3-inch intervals. The seeds/sprouts need only be covered with ½ inch of dirt, so these holes/rows need not be very deep. Plant outside. Transplant seedlings started indoors into your garden after the last frost and when the plants are at least 3-inches tall. Place the seeds so that each plant is at least 8 to 10 inches from the other plants, in rows that are 6 inches (15.2 cm) apart. This will give the parsley plenty of space to grow, which it will take full advantage of with the commencement of late Spring. Water the parsley. Water your parsley deeply at least once a week to encourage the development of a long taproot. You may need to water more frequently during extremely hot and dry periods. If you're planting your parsley in pots indoors, give them enough water so that the soil is just barely moist. Consider setting up a drip system if you're unable to water the parsley regularly. Keep weeds at bay. Weeds can easily blend in with the parsley, but they take up valuable nutrients and block out sunlight. Mulch around the plants to help the soil retain its moisture and discourage weed growth. Further, pull any weeds on sight and dispose of them far away from your garden. Thin out the parsley plants. Along the way, seedlings will need to be thinned out so that there is only one plant every 8 to 10 inches. Once the seeds start to develop into plants, go through with a pair of scissors and snip out some of the smaller or less healthy looking plants right down to the soil. If you want to transplant these seedlings to a different location, then you can carefully dig them up using a small spade. Continue adding nutrients. Fertilize the parsley once a month using a general purpose fertilizer to sustain production of the herb for the entire season. You can also add compost to the soil to help keep it full of nutrients, giving your parsley an extra boost. Harvest the parsley. When the parsley sprouts out with sets of three leaves that are fully developed, it is ready to be picked. Harvest the parsley slowly throughout the season by cutting the outer stalks of the plants just above ground level to encourage additional growth. Harvesting the leaves from the top of the plant will reduce your yield. Freeze the leaves for later use, or dry them and store them in airtight containers. Use your stored parsley within a year for optimal flavor. 
Choose a type of parsley. Select a location. Prepare the soil. Soak the seeds in soapy water. Rinse and move the seeds to another bowl of water. Dry the seeds. Start your seeds indoors. Plant at the right time. Dig your holes/rows. Plant outside. Water the parsley. Keep weeds at bay. Thin out the parsley plants. Continue adding nutrients. Harvest the parsley. Freeze the leaves for later use, or dry them and store them in airtight containers. 