Fill planting trays or individual pots with moist seed starter to within 1/2 inch of the rim.
Make a planting hole in the center of the pot with your finger or the end of a pencil. Make the hole no deeper that 1/4 inch, as marigolds do not require deep planting. If using planting trays, space the holes an inch or two apart.
Place one marigold seed in each planting hole. Cover lightly with seed starter and press down lightly to secure the seed.
Cover the seed trays or pots with clear plastic wrap and place in a warm location to germinate. The top of a water heater or other appliance that provides gentle bottom heat is ideal.
Check the seeds daily and moisten the soil, if necessary. Shoots should emerge in three to seven days.
Remove the plastic once seedlings emerge and place them on a sunny windowsill. Keep the soil moist, as seedlings can wither and die quickly without adequate moisture.
Transplant marigold seedlings to individual pots once they have their second set of true leaves. Transplant to the garden once the danger of frost has passed.