The Best Cures for Caterpillars Eating Your Geraniums


A favourite of gardeners all throughout the United States, geranium (Pelargonium spp.) is known for the brilliant green, heart-shaped leaves and large, consistent flowers that it produces from late spring until the first frost. Geranium is classified as an annual plant in the majority of regions, although it thrives in the mild weather of USDA plant hardiness zones 9 and 10, where it may be grown throughout the year. Even if a healthy geranium has a high level of resistance to pests, it might still be affected by them on occasion. Caterpillars, for example, are a common form of pest.


A moth or butterfly in its larval, or immature, stage is called a caterpillar. This pest looks like a fat worm and may be a nuisance. It is possible for caterpillars that feed on geraniums to be green, reddish, or light brown in colour. Caterpillars may come in a variety of colours. Caterpillars do significant damage to plants, often destroying the plant entirely as they consume its leaves, buds, blooms, stems, and flowers. Adult moths and butterflies do not pose a hazard to plants, but caterpillars do. Adults pose no danger to plants. The geranium budworm, cabbage looper, variegated cutworm, and geranium plume moth are some of the caterpillars that are drawn to geraniums.


Although it is an unpleasant chore, hand-picking caterpillars from geraniums is the way that is both the safest and most effective in preventing the plants from damage. It may be difficult to find caterpillars because they hide in the foliage or coil themselves up in the leaves. Caterpillars do this to avoid being seen. However, they leave behind telltale traces like as microscopic particles of excrement, chewed holes, and deformed leaves. These clues point to the presence of the pest. If you come across a caterpillar, you may either crush it underfoot or put it in a bucket of soapy water and put the container outside. Caterpillars are easy to find. Maintain vigilance and check on the plants on a daily basis.

Natural Predators and Pesticides

Insects like green lacewings, damsel bugs, pirate bugs, and certain kinds of beetles are just a few of the natural predators that help keep caterpillar populations in control. When dealing with caterpillars and other types of pests, the use of pesticides may frequently make the situation worse. This is because chemicals kill not only the caterpillars but also the beneficial insects that are responsible for properly controlling the pests. In many cases, the use of pesticides leads to an even more severe infestation of undesirable insects or animals. In addition, herbicides are not always successful in controlling caterpillars since the pests are shielded by stems and buds of the plants they feed on.

Cultural Controls

Geraniums in good health are more resistant to the harm caused by caterpillars than plants in poor health or under stress. Geraniums should only be watered when the top layer of soil feels dry, and then they should be watered well to a depth of around 6 inches. Geraniums should never be allowed to sit in muddy or soggy soil, as this may cause the plants to become weakened and more susceptible to disease and pests. The finest blooms on geraniums come from consistent fertilisation, while excessive fertilisation results in plants that are stunted and feeble. Geraniums should be fertilised once every three weeks using a water-soluble, all-purpose fertiliser that is prepared at a ratio of 2 teaspoons of fertiliser to 1 gallon of water. Remove any wilted blossoms or foliage, as well as those that are dry or have died. Remove and discard any damaged branches or leaves. Keep the space surrounding the plant clear of dead leaves and any other debris that may have fallen from the plant.

Bacillus Thuringiensis

Bacillus thuringiensis is a naturally occurring bacterium that is capable of eliminating several caterpillar species, including those that consume geraniums. Honeybees and other insects that are useful to the environment are not harmed by the chemical. In a similar vein, the bacterium is harmless to the environment and does not provide any danger to either people or animals. Even though the substance is harmless, it is essential to protect your eyes, hands, head, and upper body by using protective gear such as a hat, gloves, long trousers, and a shirt with long sleeves. Use a sprayer that attaches to your hose or one that you hold in your hand to apply the product, which can be found at most garden supply outlets. Bt is particularly useful as a therapy for young, newly hatched caterpillars; it may not be as successful for treating older, more developed larvae. When the sun shines directly on the geraniums, you should avoid treating the caterpillars with Bt. A few days or hours after the caterpillars have fed on the Bacillus thuringiensis bacterium, the bacteria will kill the caterpillars.