Pollinators—bees, birds, bats, butterflies, and other insects—are essential to plant reproduction and our food supply, responsible for one in every three bites we eat. But they face immense threats from habitat loss, climate change, and harmful pesticides, especially neonicotinoids. These pesticides, which harm insects' nervous systems, contaminate soil, water, and even human health. Nurseries play a key role in protecting pollinators by growing pollinator-friendly plants with fewer pesticides.  

Implementing IPM practices in your nursery helps manage pests sustainably and minimizes harm to pollinators and beneficial insects. Here are the key components of IPM:

Physical Controls 

  • Use physical barriers like screens and weatherstripping to keep pests away from plants.
  • Remove pests manually by washing, pruning, or using other non-chemical methods. 

Biological Controls 

  • Encourage natural predators like lady beetles, spiders, and parasitic wasps by planting nectar-rich flowers and controlling ants (which can disrupt beneficial insects).
  • Plant San Francisco Native plants, which are climate-adapted and co-evolved with local pests, making them naturally more resilient and pest-resistant. 

Cultural Controls 

  • Apply landscape fabric and mulch to manage weeds effectively.
  • Use traps, such as sticky traps for fungus gnats, to control specific pests without using chemicals. 

Selective Pesticides 

  • Use pesticides only as a last resort and select the least toxic options to protect beneficial insects. Always combine pesticides with other IPM practices and strictly follow label instructions. 
  • Consider using low toxic pesticides listed in section 2: Eliminate the use of Systemic Pesticides 

Additional Resources 

More Questions about IPM? Explore the University of California Integrated Pest Management page

Diagnose specific plant problems and identify common pests with these tools: 

  • Avoid Systemic Pesticides: Only grow and source plants that are free from systemic pesticides, which persist in the environment and harm pollinators.
  • Avoid Neonicotinoids: These neurotoxic pesticides should be avoided completely. 

Neonicotinoids: 

  • Abamectin (Agri-Mek)
  • Abamectin/Cyantraniliprole (Minecto Pro)
  • Abamectin/Thiamethoxam (Agri-Flex)
  • Clothianidin (Belay)
  • Imidacloprid
  • Sulfoxaflor (Closer)
  • Thiamethoxam (Actara) 

Category I (Highly Toxic to Bees) 

These pesticides are highly toxic to bees and other beneficial insects and should be avoided entirely. Bolded items are neonicotinoids. 

  • Abamectin (Agri-Mek)
  • Abamectin/Cyantraniliprole (Minecto Pro)
  • Abamectin/Thiamethoxam (Agri-Flex)
  • Acephate (Orthene)
  • Azadirachtin/Pyrethrins (Azera Insecticide)
  • Bifenthrin (Brigade)
  • Carbaryl (Sevin)
  • Chlorpyrifos (Lorsban)
  • Clothianidin (Belay)
  • Cyantraniliprole (Exirel)
  • Cyfluthrin (Baythroid)
  • Cypermethrin (Ammo)
  • Deltamethrin (DeltaGard)
  • Dinotefuran (Safari)
  • Fipronil
  • Indoxacarb (Avaunt)
  • Lambda-Cyhalothrin (Warrior)
  • Malathion
  • Methomyl (Lannate)
  • Novaluron (Diamond)
  • Oxamyl (Vydate)
  • Phorate
  • Imidacloprid
  • Phosmet (Imidan)
  • Pyrethrins (PyGanic)
  • Spinetoram (Delegate)
  • Sulfoxaflor (Closer)
  • Thiamethoxam (Actara) 

Category 2 (Moderately Toxic to Pollinators) 

These pesticides should only be used with caution as they pose moderate toxicity risks to pollinators. 

  • Acetamiprid (Assail)
  • Azadirachtin (Neemix)
  • Buprofezin (Applaud)
  • Chlorfenapyr (Phantom)
  • Cyromazine (Trigard)
  • D-Limonene (GreenMatch)
  • Endosulfan (Thionex)
  • Formetanate Hydrochloride (Carzol)
  • Narrow-range oil (JMS Stylet Oil)
  • Neem Oil (Trilogy)
  • Pyriproxyfen (Esteem)
  • Rotenone (Prenfish)
  • Spinosad (Entrust) 

Category 3 Pesticides (Minimally Toxic or Low Risk to Bees) 

Use these as a last resort when other methods are insufficient: 

  • Abamectin bait (Clinch Ant Bait)
  • Boric Acid bait (Gourmet Liquid Ant Bait)
  • Bacillus Sphaericus (VectoLex)
  • Cryolite (Kryocide)
  • Fenpyroximate (FujiMite)
  • Methoprene bait (Extinguish)
  • Rosemary oil (Hexacide) 

Visit Bee Precaution Pesticide Ratings for an extensive list of pesticides and their effects on pollinators. 

Phytophthora is a genus of plant pathogens that includes over 120 species, many of which threaten biodiversity, particularly in sensitive ecosystems like those in California. This pathogen spreads easily through the movement of plants, soil, and other planting materials, making it essential for nurseries to adopt preventive practices. Among the most harmful species is Phytophthora ramorum, which causes Sudden Oak Death (SOD) and has devastated oak populations in California, spreading through infected nursery stock. Protecting plant diversity, especially in regions with unique native species, requires a proactive approach to prevent the spread of Phytophthora. 

Why Phytophthora Prevention is Essential for Nurseries 

  • Threat to Biodiversity: Phytophthora pathogens reduce plant survival and success, impacting native ecosystems and potentially causing long-term damage to areas meant to support diverse plant life.
  • High Risk of Spread: These pathogens thrive in nursery environments and can be easily transported through plants, soil, and water, inadvertently spreading to new sites.
  • Unique Role of Nurseries: By ensuring all plant materials are pathogen-free, nurseries can help prevent introducing these pathogens to sensitive ecosystems and protect native species. 

With careful sourcing and handling of plants, nurseries have a vital role in preventing the spread of harmful Phytophthora species as plants are distributed across San Francisco. 

Best Practices for Nurseries to Prevent Phytophthora Spread  

Plant Setup and Organization 

  • Ground and Bench Management:
  • Keep plants elevated on benches or metal shelves to avoid ground contact with spores.
  • Discard any plants that touch the ground, maintain clean benches and tidy surroundings.
  • Plastic Pots:
  • Use cone-shaped plastic pots whenever possible to improve drainage and reduce soil contact, helping to prevent Phytophthora spread.
  • Plant Size and Duration in Pots:
  • Keep plants small within pots, as larger plants in confined pots are more susceptible to disease.
  • Avoid prolonged pot confinement by planting in the ground whenever possible, as it reduces disease risk.
  • Plant Grouping:
  • Place plants that are highly susceptible to infection at the back of the nursery, preferably on a slope to direct water runoff away from other areas.
  • Aisle Spacing:
  • Ensure adequate aisle spacing between plant groups for optimal airflow and easy access, which reduces disease spread. 

Sanitation 

  • Disinfect shoes with a footbath before entering nursery areas.
  • Heat-sterilize plastic pots before reuse to eliminate potential pathogens.
  • Disinfect propagation areas, greenhouses, tools, and containers regularly to maintain a consistently clean environment. 

Watering 

  • Group plants by water requirements, water early in the day, and avoid overhead watering to reduce leaf wetness and pathogen spread.
  • Keep hoses off the ground, and sanitize nozzles if they touch the floor to prevent contamination. 

Debris Removal 

  • Leaf and Soil Debris:
  • Regularly clear plant production areas of leaf and soil debris to prevent disease buildup. 

Soil and Potting Mix 

  • Use only heat-sterilized potting mixes and store them in sanitized containers to prevent contamination. 

Routine Inspection  

  • Regularly inspect plants and surrounding landscapes for any signs of infection and isolate any affected plants immediately. 

Material Management 

  • Contain and properly dispose of any infected materials to prevent contaminated runoff from spreading pathogens. 

For detailed guidance, consult the following resources

For Growing your own Nursery Stalk Consult:  Best Management Practices for Producing Clean Nursery Stock &  Restoration.Nsy_.Guidelines.2021.pdf 

Visit this List of Accredited nursery stalk growers when sourcing plants, when buying from nurseries not on this list, inquire about their phytophthora protocols before purchasing plants: Participating Nurseries | AIR 

What Plants Should I Avoid Selling?

Our pledge encourages nurseries to avoid selling any plants listed by the California Invasive Plant Council as 'highly invasive' or 'moderately invasive', as these species pose significant risks to California’s ecosystems.

Need a Comprehensive Guide to SF Native Species? 

sfe bd sfplantfinder cta

Additional Resources and Inspiration: