Did You Know Marigolds were first discovered by the Portuguese in Central America in the 16th century?? "Marigold" is derived from "Mary's Gold", and the plant is associated with the Virgin Mary in Christian stories. Because of the flower's heavenly association it was thought to be a bringer of good luck and to ward off evil and witchery.
Planting Marigolds amongst your tomatoes is considered "companion planting". Annual Marigolds can be used anywhere to deter Mexican bean beetles, squash bugs, thrips, tomato hornworms, and whiteflies. They are also known to repel harmful root knot nematodes (soil dwelling microscopic white worms) that attack tomatoes, potatoes, roses, and strawberries. Marigolds omit an odor that many insects find offensive so when you plant marigolds you are actually helping keep insects away from the area you are planting the marigold flowers in. Insects do not like to be around marigold flowers.The root of the Marigold produces a chemical that kills nematodes as they enter the soil. If a whole area is infested, at the end of the season, turn the Marigolds under so the roots will decay in the soil. You can safely plant there again the following spring.
Marigolds are easy to grow and have a long flowering period. African marigolds have a upright growth and can reach a height of 30-40 inches, while French marigolds grow to only 8-16 inches. African marigolds come in shades of yellow and orange, while French marigolds are often multicolored in shades of orange, yellow, mahogany and crimson. Both are suitable for massed plantings or pots. They are attractive as cut flowers if the scent isn't a problem. Change the water in the vase frequently.
Marigolds are grown from seeds. They like full to partial sun. Marigold seeds can be directly sowed into your flower garden, or seeded indoors for transplanting later. I recommend planting Marigolds in pots and containers indoors, then transplanting them outdoors. This allows you to make the proper spacing without the need for thinning seedlings.
Sow Marigold seeds early in the season and cover lightly with soil. Water thoroughly once. They germinate easily and will grow quickly, producing their first of a continual display of blooms by mid-summer.