Marigolds not just another pretty flower

Marigolds make a great annual bedding plant. They are also very popular and a well-used annual for the vegetable garden. There is certainly a large variety to choose from for adding to your landscape. From the tallest, the African marigolds at 3 feet tall to some of the shorter marigolds, the dwarfs, only 6 inches tall. There is a variety of color from creamy white to combinations of orange and red and much more.

Lucky for us, marigolds like full sun and tolerate the heat. They do need well-drained soil and soil that is moist but not wet. They are perfect for edging a bed or planting amongst vegetables. Marigolds do attract beneficial insects such as lacewings, lady beetles and parasitic wasps.

These predators do consume a variety of nonbeneficial insects. Lacewings eat aphids, mites and a wide variety of soft-bodied insects. This includes eggs, thrips, mealybugs, immature whiteflies and small caterpillars. Lady beetles eat mostly aphids. They also will eat mites, whiteflies and scale insects. Parasitic wasps eat a lot of insect larvae. They are good at controlling aphids, scale, whiteflies, sawfly larvae, ants, leaf miners and several types of insects. They will parasitize the eggs of European corn borers, tomato hornworms, codling moths, cabbage loopers and imported cabbage worms. Perhaps this answers the question of why marigolds are relatively pest free.

Recent studies including the one published by Backyard Farmer, July 7, 1999, indicate that marigolds contain compounds toxic to root knot and other plant-parasitic nematodes. These nematodes are microscopic round worms that damage plant roots. This leads to reduced yields and poor quality of the vegetable crop. Root nematodes are usually brought in on other plant material coming into the area.

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