Marigolds (Tagetes) are annual or perennial flowers from the aster family, native to South America. The single, double or semi-double flowers bloom in shades of red, orange and yellow during late spring and summer. The showy flower heads are composed of raylike petals, and the featherlike foliage is deeply cut. The flowers thrive in well-drained soil and areas of partial sun. In the book "Management of Horticultural Crops," T. Pradeepkumar says marigolds can be easily propagated using softwood cuttings.
Prepare rooting medium by filling a small pot with equal amounts of sand, peat and perlite. You can also use fine gravel to root the cuttings. Pour about an inch of the rooting hormone into the plastic cup.
Cut 4-inch-long stem sections from softwood growth, measuring from the stem tips. Use sharp scissors and select stems that have not yet flowered. Softwood stems are soft and immature current-year growth that is not woody or hardened.
Remove all leaves from the lower half of the cuttings. Leave a couple of leaves at the top to continue producing a natural substance that helps in root production.
Insert a pencil at a depth of about 2 inches to create planting holes in the rooting medium. Dip the base of each cutting into the rooting hormone and plant immediately in individual planting holes. Do not plant deeper than 2 inches.
Firm the soil around the cuttings. Water well. Place the entire pot in the plastic bag. Stick a chopstick in the rooting medium to keep the bag from collapsing. Close the top with a rubber band to create a greenhouse effect.
Place the pot in a warm, bright area out of direct sunlight. Open the bag every three to four days and water enough to keep the rooting medium moist. Close bag after watering. It generally takes a few weeks for cuttings to root.
Transfer rooted cuttings to a medium-sized container filled with a well-draining potting soil. Let the plants become established before transplanting to a permanent spot in the garden.