Regardless of type of marigold (Tagetes spp.), the quill-like cream and black striped seeds are nearly always the same size and shape. One of the easiest warm-season annuals to raise, even for inquisitive kids, they quickly grow and produce yellow or bright orange flowers. Tall bushy marigolds are usually called African marigolds while the short, petite rounded plants are considered French marigolds. Sow the seeds directly outdoors in the garden soil or in pots indoors, allowing you to grow small plants to later transplant.
Till the soil to a depth of 4 to 5 inches with a garden hoe in the area of the garden you wish to sow the marigold seeds. Do this about one week prior to the last expected spring frost date in your area. Smooth the area out when done and allow the soil to settle.
Wait until the expected last spring frost date passes and the garden area's soil is not wet after a rain, about 24 hours later. Walking on freshly tilled or wet soil compacts it, making it hard once it further dries out. You also avoid any muddy soil clumps when you wait to plant after a rain.
Scrape a shallow furrow about 1/4 inch in depth with the garden hoe or your hand. Pulverize any soil clumps with your hands. Alternatively, poke your finger into the soil to a depth of 1/4 inch to create a petite planting hole. One-fourth inch is no larger than the size of your pinky fingernail.
Place the marigold seed in the furrow, spacing seeds 3 to 4 inches apart in the furrow.
Gently replace the soil over the planted seeds, making sure you bury the seeds no more than 1/4 inch deep. In lighter, sandy soils cover the seeds up to as much as 3/8 inch of soil. Lightly tamp the soil down atop the seeds with your hand. Do not pack the soil.
Sprinkle water from a sprinkling can gently over the seeded area, saturating the soil so that the water reaches to a depth of about 1 inch.
Monitor the planting area for the next one to two weeks, sprinkling water in the area when the soil top dries. Depending on how warm the soil is, seeds should germinate any time from seven to 10 days and begin poking up from the soil.