Thrips are small insects that pose a threat to indoor and greenhouse ornamental plants, often causing silver-streaked damage and distorted new growth. They are difficult to manage because they hide deep within plant crevices. Bonide Systemic Granules Insect Control offers a popular, long-lasting solution for managing these pests in non-edible potted plants and outdoor ornamentals. This product provides protection from the inside out, offering an alternative to frequent topical spray applications and helping to safeguard plant collections from extensive damage.
How Systemic Insecticides Work
The effectiveness of these granules stems from their active ingredient, Imidacloprid, a chemical compound belonging to the neonicotinoid class of insecticides. Once applied to the soil, the granules dissolve with water, allowing the plant’s roots to absorb the Imidacloprid along with moisture and nutrients. From the roots, the chemical is translocated upward through the plant’s vascular system, saturating the tissue of the stems and leaves.
The entire plant becomes toxic to pests that feed on it, which is especially effective against sucking and chewing insects like thrips. When a thrips punctures the leaf surface to ingest plant sap, it consumes a lethal dose of the insecticide. This systemic action is particularly advantageous for thrips control because it targets pests that often hide in protected areas, such as unfurled new leaves or flower buds, where direct contact sprays struggle to reach.
Applying the Granules Safely and Effectively
Application requires consulting the product label to determine the correct dosage, as the necessary amount varies based on the size of the container or the height of the shrub. For containerized plants, the required amount of granules must be measured precisely using a dedicated measuring utensil and spread evenly over the surface of the soil around the base of the plant.
After application, the granules need to be lightly cultivated or scratched into the top one to two inches of the potting mix to ensure they are incorporated into the soil structure. The most important step for activation is a thorough, immediate watering, which starts the dissolving process and allows the roots to begin absorbing the chemical. To optimize root absorption, it is advisable not to water heavily again for approximately ten days following the initial application. For continuous protection, re-application is generally recommended every eight weeks during the growing season.
Plant Use Restrictions and Safety
Due to the persistent nature of Imidacloprid, the product label places strict prohibitions on where the granules can be used. Bonide Systemic Granules are formulated only for use on ornamental plants, meaning they must never be applied to edible crops, including vegetables, herbs, or fruit-bearing plants. This restriction prevents the insecticide from entering the human food chain.
The systemic nature of the insecticide also carries environmental implications, especially concerning pollinators. Imidacloprid is highly toxic to bees and other pollinators, necessitating extreme caution when the product is used on outdoor flowering plants. To mitigate the risk to beneficial insects, the granules should not be applied to plants that are currently blooming. For indoor use, general safety precautions involve storing the product in a cool, dry place, securely locked away from children and pets. When handling the granules, wearing protective gloves and thoroughly washing hands afterward minimizes personal exposure.
Timeline for Thrips Control
Systemic control is not instantaneous because the active ingredient requires time to be absorbed by the roots and travel throughout the plant’s structure. Results should not be expected immediately, as the translocation process from the soil to the furthest leaves and stems typically takes several days to a week. For heavy infestations, noticeable decline in the thrips population may take up to two weeks.
Once fully absorbed, the plant remains protected, and the product provides long-lasting residual control, often for up to eight weeks before a re-application is needed. Monitoring the success of the treatment involves observing new growth. If the systemic control is working, new leaves and stems should emerge free of the characteristic feeding damage, silver streaks, and distortion caused by the pests. This long duration of protection simplifies management.