Caladiums (Caladium spp.) are sometimes called angel wings, a testament to the beauty of these tropical foliage plants. Leaf damage from pests spoils their beauty and may affect the vigor of the plant. Caladiums contain calcium oxalate crystals, so rabbits and deer usually leave them alone. If your caladium has large holes, it has likely been attacked by slugs or snails.
Caladiums thrive in moist, shady spots, which are the same conditions slugs and snails prefer. You can make cultural changes to help prevent these damaging mollusks by removing potential hiding spots, such as tall weeds and plant debris. If you have a serious infestation, you may have to avoid organic mulch such as straw and grass clippings. Because slugs and snails are susceptible to drying out, it can also be helpful to space plants farther apart to increase air circulation.
You can place boards or other flat objects in the soil near your caladiums to act as traps for slugs and snails, which will hide underneath. Check the traps regularly and remove and destroy any pests. Pennies and copper wire can act as a protective border around caladiums, as slugs and snails dislike crawling over copper materials. You can also pick slugs off by hand in the evening, when slugs and snails are most active, and drown them in soapy water.
If you decide to resort to chemical controls, only apply iron phosphate-based slug and snail bait. Iron phosphate is considered safer around pets than products that contain mesurol or metaldehyde, which is attractive and potentially fatal to dogs. If you're spraying, always keep children and pets away from the area. The usual rate for iron phosphate baits is 1 teaspoon per 1 square yard of ground, but follow label instructions exactly. Always keep chemicals out of the reach of children. Bait is best applied on a warm, clear night to boards and trap, advises North Carolina Cooperative Extension.
A healthy caladium is more likely to survive a pest attack. Caladiums grow as perennials in U.S. Department of Agriculture plant hardiness zones 8 to 10, where they prefer partial shade or filtered sun. The leaves will scorch in direct sun. Caladiums should be planted in a fertile, organically rich and acidic soil in a protected area. Plants grown in an exposed spot may develop wind or hail damage that causes large holes and tears, resembling pest damage.