Pest Control with Worm Casting

Worm Casting is a great natural pest control. An impressive benefit is the natural resistance to insect infestation. The digestive system of earthworms produces an enzyme called chitinase. This enzyme is a degrader of chitin, the substance that comprises the exo-skeletons of most insects. When used properly, worm casting acts as a natural insect repellant. If a bug feeds on the leaves of a plant which has absorbed the chitinase, its exoskeleton will soon begin to dissolve, and death will come quickly. I especially recommend applications against the most stubborn sapsuckers like ahpids, thrips, whiteflies, mealybugs, and mites. An application of worm castings should be about 1″ thick and a foot or so in width. Spread it around the drip line of the tree or shrub and cover with 2″ of casting.

Insect exoskeletons are made from chitin. Plants grown in worm casting & sprayed with worm tea become rich in chitinase. Chitinase will dissolve an insect’s exoskeleton. This causes most insects to quickly lose interest in your plants, fruit, vegetables, flowers, or grass repelling many of them before they decide to make a meal of your plants.

Although casting is murder on those pesky insects it is safe for you, your kids, and your pets. It can even be stored safely indoors.


Knock the top of ant hills off and spread a layer about 1/4″ thick of casting across it. Watch what happens. The ants will be gone within a few days.

Special Note:

We have found using Worm Casting or Worm Casting Tea reduced the number of insects in our garden tremendously. After using it on our flowers, shrubbery and lawn we noticed fewer insects on or around them also. You get the picture; less insects outside ultimately means less insects getting inside your home. It is a win across the board.

North Carolina State University researchers have dug deeper into the mechanisms behind insect resistance of plants grown in soil amended with vermicompost, and the preliminary results suggest this may provide an ecological friendly means of managing pests in vegetable crops.

Yasmin Cardoza, an entomologist and soil arthropod ecologist, along with graduate student Amos Little, found that different insect species responded differently to host plant resistance of brassica crops. They also determined that it takes as little as a 20 percent concentration of vermicompost mix in the soil to boost the resistance of host plants against caterpillar and aphid pests. (more…)– NC State University