Marigolds can make colorful additions to any flower bed or garden. They even fare well as potted plants. To get the longest growing season from your marigolds, start the seeds indoors before transplanting them outside. According to Purdue University's Department of Horticulture, seeds should be started six weeks before the expected date of the last frost in your area. With some simple indoor prep, you can have your marigolds well on their way to impressive outdoor blooms.
Put the seed-starting potting mix into a large bucket, and wet it down until it is moist.
Fill the peat pots with the potting mix until it's just three-quarters of an inch from the top of the pots.
Take your forefinger and put a small dent in the top of the soil in each pot.
Drop a marigold seed in the dent in the soil, and then cover the seed with a quarter-inch of potting mix.
Put the peat pots on a large tray, and lay a sheet of clear plastic wrap across the top. This will help keep in moisture and heat.
Place the tray of peat pots on top of a refrigerator, hot water heater or a heating pad set on low. This bottom heat source will help the soil reach and maintain a temperature of 60 degrees or higher, which is needed by the marigold seeds to germinate.
Remove the plastic from top of the tray when the seeds have germinated. This will take approximately three to four days. Move the tray to a spot near a window with direct sunlight.
Keep the peat pots moist by putting water in the bottom of the tray.
Set the tray outdoors for three to four days before transplanting the peat pots to the flower bed. This will allow the seedlings to become acclimated to the outdoor weather before being put in the ground.