Answer: Pests seldom bother vinca, although you may occasionally find aphids on the plants and slugs/snails hiding in the plants. Larger pests such as rabbits and deer avoid eating vinca. In deer infested areas, vincas are highly recommended plants that will provide summer color. Wash aphids off with hard spray of water from the garden hose and/or sprinkle slug/snail bait (I use Sluggo) in among the plants. Moth balls won't really deter pests and they can harm the plants and the soil if you sprinkle them around in the garden.
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