The pungent smell of French marigolds deters whitefly from your tomato plants. companion planting - used for many years - look for natural plants to grow for natural sprays - I grow completely organic now.
Lemon Balm Plant - Melissa officinalis | London Dispensary said in 1696 that "Balm given every morning, will renew youth, strengthen the brain and relieve languishing nature." A hardy perennial with a lovely lemon smell, it prefers shade and is best grown in pots. Five leaves in hot water is claimed to be a memory restorative and gives a sense of well being for those suffering from stress.
Tumbling Nasturiums Nasturtiums keep bugs away from squash and broccoli. Nasturtium is an excellent companion for many plants. It is a companion to radishes, brassicas, deterring aphids, squash bugs, and striped pumpkin beetles, and improving growth and flavor. Plant as a barrier around tomatoes, cabbage, cucumbers, and under fruit trees. Deters wooly aphids, whiteflies, cucumber beetles see: ... http://www.ghorganics.com/page2.html