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. The scent is strong and somewhat unpleasant, and is effective in repelling many garden pests. 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 can be grown in all but the coldest climates. Marigolds can be sown directly in the garden when danger of frost has passed, or they can be started indoors for earlier blooms. Space the plants 8-16 inches apart depending on the variety. Water deeply and regularly, especially in hot weather. Mulching between plants will help to conserve moisture. Sidedress monthly once plants are established. If given an early start, they will bloom throughout summer and autumn. Some will flower into winter in warmer areas. Marigolds are sometimes attacked by whiteflies and mites. Regular hosings will keep these pests from becoming established.