Castor Bean Plants & Slugs

What Eats Castor Bean Leaves

• The larvae of the Ricini silkmoth (Samia cynthia) feeds on castor bean leaves with no ill effect, but it would be unusual to find this Asian species in North American gardens. The most likely predators are slugs. Slugs are shell-less mollusks that leave a slime trail on leaves, so you can easily identify whether they are the culprit.

Home Remedies

• Home remedies to thwart slugs are only minimally effective. Among these remedies are gritty substances such as crushed eggshells, ashes, sand, chicken grit, crushed oyster shells and coffee grounds. Wrapping stems or pots with copper tape barriers or setting out tuna cans filled with beer are tedious methods for the busy gardener and can't conquer a slug invasion. None of the home remedies work as well as diatomaceous earth or organic iron phosphate bait.

Bait

• Clean up garden beds in fall by raking up leaves and plant debris and putting it in your compost pile. Scatter iron phosphate granules lightly around and under plants and near slug hiding places, such as garden edging and rocks. Reapply each time the bait disappears. Start baiting for slugs again in early spring before they have a chance to damage your plants. Iron phosphate baits, sold under brand names such as Sluggo or Escar-Go, are safe for pets and wildlife. The granules dissolve into beneficial nitrogen.

Diatomaceous Earth

• A sharp, silicon dust made up of minute fossils, diatomaceous earth works by irritating the slug's smooth belly. Wear a dust mask while applying it, because it is fine and can be inhaled, irritating your lungs. Sprinkle it around the base of plants. The dust disappears into the ground in rainy weather, so reapply it often.