Marigolds are attractive in mass plantings, whether the bright blooms are grown in a garden bed or if they are overflowing from a planter. Low maintenance and drought tolerant, marigolds require little work to produce blooms all summer long. An inexpensive way to plant a large number of these long-lasting annuals is to start the marigold seeds at home. Start the seeds indoors six weeks before you plan to transplant them to the garden and they will be ready to bloom as soon as they are in their permanent beds.
Fill 2- to 3-inch diameter seed pots with a moist, soil-less mix or a potting mix formulated for seed starting, as these are sterile and have fine texture that helps ensure the seedlings health.
Sow two marigold seeds per pot. Place the seeds on the surface of the potting mixture. Sprinkle ¼ of an inch of mixture on top to cover the seeds.
Cover the pot with a plastic bag to help retain soil moisture during germination. Set the pots in a warm room (75 to 80 degrees F) to germinate, which takes approximately three to five days.
Remove the plastic bag when the sprouts appear. Place the pots in a sunny windowsill in a room with temperatures between 68 and 70 degrees F. Water the soil in the pots once every three to five days or as needed to keep it moist but not soggy.
Fertilize the seedlings with a ¼ strength solution of a balanced, soluble houseplant food. Begin fertilizing when the seedlings are 1 week old. Fertilize once per week until they are transplanted in the garden.