Boxwood Insect & Mite Treatment by SavATree Insects, Mites & Diseases Boxwoods can be affected by a variety of insects and mites, with the boxwood psyllid (Psylla buxi), boxwood mite (Eurytetranychus buxi), and several scale insect species among the most common. PSYLLIDS Psyllids are small sap-feeding insects that can harm shrubs like boxwoods by injecting toxins during feeding. This feeding weakens new growth, leading to leaf damage and reduced plant health. Without proactive management, psyllid infestations can cause long-term damage on affected boxwoods. MITES Mites are tiny arachnids that feed by piercing plant cells and extracting their contents. They multiply quickly, especially in warm, dry conditions, causing discoloration and weakening of foliage. High mite populations can severely stress plants and contribute to overall decline. SCALE Scale insects are sap-sucking pests protected by waxy coverings that shield them from natural enemies and treatments. They feed on plant sap, weakening their hosts and sometimes causing branch dieback. Soft scales have a leathery, pliable shell and produce honeydew, which promotes sooty mold growth that further harms plant health and appearance. Hard, or armored, scales have a hard, shell-like covering that does not produce honeydew but can still cause damage by feeding on plant cells beneath the bark or leaves. Each of these invaders have a unique life cycle and damage pattern, but all can contribute to long-term plant stress and decline if left unmanaged. Signs of an Infestation Catching infestations on your boxwoods early is the best way to prevent widespread damage. If you’re in need of boxwood insect damage identification or have noticed possible boxwood mite symptoms, reach out to an ISA Certified Arborist at SavATree for proper diagnosis. Look out for these common signs of insect damage on boxwoods: Psyllids: Psyllids in their nymph stage - the immature stage after eggs hatch - feed by piercing plant tissues and injecting toxins which disrupts normal leaf and shoot development. If there is an active psyllid infestation, you might notice some of the following warning signs: Cupped or inward-curled new leaves Deformed shoot tips that may not open properly White, waxy secretions on the undersides of new leaves or shoot tips Mites: Mites puncture individual leaf cells and extract their contents, creating fine pale spots called stippling. As feeding continues, the foliage takes on a bronzed or discolored appearance and loses its healthy sheen. Heavy mite populations can lead to premature leaf drop, increased drought stress, and a greater disease susceptibility. Common signs of a mite infestation include: Fine stippling or bronzing on leaves Noticeable damage during warmer months (but egg-laying may begin earlier, so early monitoring is also important) Reduced leaf shine and vigor Scale Insects: Scale insects insert their mouthparts into stems, branches, or leaves to siphon sap, depriving plants of essential nutrients. Heavy infestations can cause leaf yellowing, branch dieback, and stunted growth. Soft scales also excrete honeydew, which encourages sooty mold growth—a black fungal coating that blocks sunlight and interferes with photosynthesis. If it’s a scale infestation, you might notice: Small, stationary bumps on stems or leaves (brown, gray, or white) Yellowing leaves, plant stunting, and branch dieback in heavy infestations Sooty mold on leaves or nearby surfaces (soft scale only) Where and When to Look for Them Psyllids lay their eggs in late summer beneath bud scales, where they overwinter. These eggs hatch in early spring as buds begin to open, making this time critical for inspecting new growth for signs of psyllid activity. Mite populations typically increase from late spring through summer, especially during warm, dry conditions. Regularly checking the undersides of leaves during this period can help catch infestations early. Scale insects undergo a mobile crawler stage in spring or early summer, varying by species. This stage is the most vulnerable and, therefore, the best time for management. Scales usually settle on stems, branches, or the undersides of leaves, often in concealed areas, so thorough inspections during crawler emergence are essential. Treatment for Insects & Mites on Boxwoods Our ISA Certified Arborists use targeted, science-based strategies to stop boxwood insects and mites before they cause lasting damage. Treatment timing is critical, since each has a period when it’s most vulnerable. Timing may vary based on the specific region and climate of the infestation, and should be confirmed by a local SavATree professional before treatment. How to Treat Psyllids – Because psyllid nymphs cause the most damage early in the season, we apply treatments in spring as buds begin to open, before new growth hardens. This approach interrupts their feeding cycle and protects developing leaves. How to Treat Mites – Mite populations often peak in warm, dry weather. We monitor activity closely and time applications when populations are actively feeding. Our programs may include horticultural oil sprays to smother overwintering eggs and targeted applications for active outbreaks, ensuring control without harming beneficial insects. How to Treat Scale Insects – The crawler stage in spring or early summer is the best window for control. Our arborists may use horticultural oils to suffocate young crawlers or targeted insect growth regulators to disrupt their development. For heavy infestations, systemic treatments that move through the plant’s vascular system provide long-term suppression. To improve the overall health and resilience of your boxwoods, your arborist may suggest the following treatments: ArborHealth® fertilizer, to deliver essential nutrients to the soil and enhance plant growth and vigor ArborKelp®, a biostimulant that encourages nutrient uptake from the soil, heightens stress tolerance, and improves fine root growth Organic Soil Enhancer, a carbon-rich product that improves soil structure and microbial activity by restoring organic matter to the soil By combining precise timing, targeted insect treatments, and comprehensive plant health care programs, SavATree ensures your boxwoods remain healthy, vibrant, and insect-free throughout the growing season. How to Prevent Insects & Mites from Infesting Your Boxwoods The best way to protect boxwoods from psyllids, mites, and scale insects is to maintain strong, healthy plants that can better withstand and recover from stress. Proper watering, fertilization, soil health care, and thoughtful pruning all contribute to a more resilient landscape. SavATree’s ISA Certified Arborists specialize in proactive monitoring to spot early signs of insect activity, allowing for quick action before infestations escalate. By combining regular inspections with customized plant health care plans, we help keep your boxwoods thriving. Where to Find Boxwood Treatments Near You Psyllid, mite, and scale populations can increase quickly and cause significant damage if left unmanaged. Our ISA Certified Arborists understand the biology and behavior of these insects and develop targeted treatment plans based on your local environment and the specific plants affected. Whether you need early detection, monitoring, or precise applications timed to insect life stages, SavATree offers customized insect and mite management solutions to protect and maintain the health of your landscape. Contact SavATree today to schedule a consultation and protect your boxwoods from the damaging effects of psyllids, mites, and scale insects. Contact us today to schedule a consultation with an expert arborist.