Whiteflies can be serious pests. Fortunately there are steps you can take to deter these bugs. Introducing predatory insects can help, but there are several plants that can be grown in between crops that help to repel the whitefly.
When planted near other crops, marigolds can be very effective pest deterrents. The marigolds must be a scented variety to work, as whiteflies seem to hate the scent of the flowers. Planting marigolds with tomatoes or in the greenhouse can help keep whiteflies away.
Nasturtium is a useful plant as a whitefly repellent, especially to plants in the cabbage family. A low-growing plant, nasturtium makes an excellent ground cover beneath crops to deter whiteflies.
Many herbs give off a strong smell, deterring or repelling whiteflies. Herbs that can be beneficial in the garden for this reason include basil, peppermint, oregano, thyme and wormwood. It should be noted, however, that mint tends to be invasive, and although it works well as a whitefly deterrent, mint could take over your garden.