VHG September 2026 Newsletter
We plant flowers, shrubs and trees to add color to our landscape, increase the value of our home, to cut and design with and to attract and support bees, butterflies plus other beneficial insects. When a plant is marked as “pollinator-friendly”, most gardeners assume it is safe for all pollinators. While choosing the right plant for the right space is key to success, so is knowing how the plants we buy are commercially grown.
While we travel down the road to our local garden center, many of the plants we buy have traveled more miles than we realize. Herbaceous plants may start as a minute plant in a tissue culture lab before being bought by a nursery specializing in producing plant plugs. The plugs are then sold to a wholesale nursery where they are potted up and grown to a saleable size. For trees and shrubs, there are nurseries that propagate these woody plants by rooting cuttings and others that then grow them on to a whip size. The young whips, or slender saplings, are grown to a saleable size by wholesale growers before being sold to retailers. Along the way there are many hands involved in the process, making it difficult for a retailer to know about each growing practice a plant experiences in its journey to a garden center.
Peggy Singlemann
I will say, gone are the days of blanket pesticide applications as growers have embraced Integrated Pest Management practices. These practices focus on regular monitoring for issues, pest/disease identification and defining a threshold of insect/disease pressure on a crop. If a problem persists past the threshold, then the grower targets the infected plant(s) with low-level inputs first before reaching for higher-level products. In my experience, the less impactful pesticides manage the issue more times than not. The practice of IPM is applicable to the home garden, too. It starts with walking through your landscape regularly.
Present-day products are formulated differently and can target a specific type of insect, a point in their life cycle, a specific cell division during a plant’s growth or even a stage in the development of a disease. Many products are synthetic or modified natural hormones, and compounds developed to break down faster in both the plant and environment. These are not the pesticides of the past.
Unfortunately, some terms regarding pesticides get used improperly and cause confusion. For example, the word systemic. Systemic defines the characteristic, mode or action of a pesticide. Systemic means the product can be taken up or absorbed and then moved within the plant. Each type of pesticide has a defined mode of entry, and whether it is applied to the roots or sprayed on the leaves determines its movement within and its longevity. This is important for applicators to know because of the impact a product has on pollinators. The residues of some systemic insecticides can persist not only in the plant but in the pollen and nectar, even in flowers that develop after treatment. Research has proven that some neonicotinoid products can remain present in flowers for weeks, even months, after application. While in trees, some systemic-type products can remain active in a plant for a year or more. Each product has its own period of action, so a general statement declaring all systemics remain present in a plant for years after application just isn’t true.
Another term that is frequently misused is Neonicotinoids, which is a defined class of insecticides. This word is sometimes erroneously used interchangeably with the word systemic. Neonics is the slang word for this group of insecticides that affect an insect’s central nervous system, causing paralysis and death. Active ingredients in this group include imidacloprid, clothianidin, thiamethoxam, dinotefuran or acetamiprid. While each of these neonics is systemic, each active ingredient has a different formulation and targets different pests. The EPA confirms there is potential for pollinator exposure from the residues found in a treated plant’s pollen and nectar. The result of this research is why members of this class of insecticides have been banned in many countries, and in the US, many states have relabeled them as “Restricted Use”. This means it is not available for homeowner use, and only licensed pesticide applicators can apply the product.
Professional growers have a licensed pesticide applicator on staff. This person is educated in all classifications of products, from insecticidal soaps to weed killers. Licensed pesticide applicators are trained to follow the restrictions listed on a label because the label of any product is the law.
Peggy Singlemann
Circling back to the plants in the garden center, the question that weighs heavily is “How long does a pesticide last?” Unfortunately, the answer is, it depends. It depends not only on the product, its active ingredient and formulation, but also on the application rate and method, the weather and growing conditions, the time between treatment and flowering or harvest and the plant species. As I mentioned earlier, the active ingredient of any product is listed on the label, and not all are systemic nor do all persist indefinitely on the plant. The detailed instructions on how to apply, when to apply, when not to apply, which plants can tolerate the formulation and the varying mixing ratios for targeting different insects or diseases are also on the label. Over the past few years, the EPA has required pollinator- related restrictions and environmental hazard information on pesticide labels when a product has an impact on one or the other. The pollinator-related restrictions apply to bloom-time, crop-stage, the time of day and reducing the application-rate. Keep in mind that many organic products affect pollinators and people, too, making these EPA application restrictions applicable to their use as well.
While at the nursery, you can ask the manager about the growing history of the plants sold at the garden center. You may be surprised to learn the pest management practices applied at your local garden center align with your goals for sustainability. Still, you can ask questions to learn where the plants are from, if they were recently treated, and if so, what was the active ingredient? Other questions can focus on pollinator-friendly practices and whether the nursery carries USDA Certified Organic plants. Bear in mind, some ornamental or native plant nurseries use chemical-free, pesticide-free or “naturally grown” practices instead of paying for an official USDA Certified Organic seal.
If the treatment history cannot be determined, then the decision is yours to buy or pass. Unfortunately, there isn’t a universal waiting period that makes every treated plant pollinator safe. However, you can purchase products at your local garden center to sow or propagate your own plants with, and the staff will be happy to help guide you along the way.
If that doesn’t interest you, then become an informed plant buyer. Seek out wholesale growers that embrace practices that align with protecting pollinators and ask which retailers they sell to. Your preferences and your questions tell growers and retailers that pollinator-safe production does matter, and you may be surprised to learn it matters to them, too. After all, we are all growing and learning, together.
Happy Gardening!
Peggy
