Solving Spider Mites in Cannabis
Sep 01, 2025
Spider mites are sneaky—but the damage they cause isn’t. If you're growing cannabis, knowing how to spot early signs and act fast can make the difference between a clean canopy and a high pressure issue.
In cannabis cultivation, spider mites often start in the shadows—lower leaves, inner canopy zones, or tucked into stem folds where airflow is low and visibility is limited. Early signs include tiny yellow or white speckling on leaves, often mistaken for nutrient issues or light stress. As pressure builds, mites spin fine, silky webbing across stems and foliage—a signature symptom that sets them apart from other common plant problems.
Spider mites can enter grow spaces through clones, clothing, tools, and even air currents. Pressure levels range from low (a few mites and minimal damage) to high (dense webbing and all life stages present). Before introducing new clones, quarantine them for 3–5 days in a clean, low-airflow space and inspect with a scope—this helps expose hidden problems before they spread to your canopy.
For visible damage prior to flowering, bottle formulations of beneficials like Spidex (Phytoseiulus persimilis) and Spical (Neoseiulus californicus) should be applied directly to affected areas—they feed on all life stages and work quickly to reduce pressure. Once things are under control—or if you're currently managing the problem with a spray—preventative sachets can be brought in to establish lines of defense, as “clean-up crew” and to protect against future pressure. Check out our Spidex Vital Go sachets, engineered for combatting spider mites through precision placement in hot spots for prevention against high pressure problems. Another great tool is Isarid (Isaria fumosoroseus), a mycoinsecticide that can help bridge the gap between spraying and introducing beneficials. Isarid is compatible with biocontrols and supports a smoother transition between chemical intervention and biological controls.
Experiencing issues while in flower? We reocmmend switching from bottle product to sachets or using diboxes (hanging baskets) to deply the loose predatory mites. If you're dealing with an active Spider mite problem in late-stage flower, check out our Spidex Boost sachets, specifically engineered for Cannabis. Spidend (Feltiella acarisuga) is also great for hotspot treatment and pairs well with Spidex. Dealing with a spider mite problem that seems to pop up everywhere as soon as you notice it?
If you're transitioning from sprays to beneficials, consider a phased approach: reduce chemical use over 3–5 days, apply Isarid to soften pressure, then introduce beneficials.
Want to learn more about how to solve spider mites? Check out our article Solving Spider Mites for identification tips, treatment strategies, and biocontrol recommendations—all in one place.
Some chemicals negate the effects of beneficial controls. If you’re navigating the shift from chemical to biological control, we’re here to help—just reach out to us at orders@koppert.com or simply message our live agents through the chat box in the bottom right hand corner of the screen.
Treating a large space and looking for expert advice on IPM strategy? Just fill out our contact us form Personal Service Inquiry | Natural Enemies and we’ll reach out with tailored support to help you build a plan that works.
Questions about spray compatabilities? Check out our free compatability charts or use our compatability tool to search your specific brand here.
