Pesticide Control: Commentary on Bayer
As those of you who’ve been following this blog for a while (my condolences) might know, I tend to lean heavily on aesthetics, philosophy, and flights of fancy. Well, just to balance things out a bit, I thought we’d chat briefly about the raw side of bonsai: Pest control.
Mostly I’d like to talk about Bayer today. For those of you unfamiliar with Bayer, they make a line of products that work against many pests. They are effective, and their products are easily found in many stores. Those with 50 trees or less might well find that careful use of Bayer can take care of many pest problems, including Adelgids, Aphids, Borers, Caterpillars, Leafminers, and Scale. Curiously, although there is some evidence it can affect the life cycle of Spider Mites, it is not very effective against them and may in fact harm the predators of mites more than the mites themselves, causing an inverse response that can cause outbreaks of the mites.
The insecticide active ingredients in Bayer are primarily imidacloprid, and secondarily, clothianidin. They are insect-specific poisons that have much less toxicity and danger to mammals, fish, and amphibians (although there is some). These chemicals are of similar chemical structure as nicotine which has been used as an insecticide for a very long time. At first glance, this product seems to have great utility.
But, please note: Imidacloprid is not a benign insecticide. Its use must be limited to non-bee attracting plants. Imidacloprid is thought to be a major contributing factor in honeybee colony collapse disorder. Consider a different pest control with your flowering bonsai.
With that cautionary tale regarding bees, you may find limited use of Bayer to be helpful. Unfortunately, Bayer makes several products which are so similar that they have confused me several times in the past. Rather than run through all the products, I’ll just post a picture here of the label of the one I’ve found most useful. The reasons that this is the one I prefer is because it is 1. listed for use with containerized plants (which many of the others aren’t), 2. it’s a long term systemic as opposed to a short term systemic. That it has a little bit of fertilizer in it does not bother me too much, especially because one application will last many months. (I prefer pinpoint control with fertilizing each individual plant, and if it had more fertilizer in it I’d be shy of using this product.)
One teaspoon per gallon takes care of a lot of common pests. Drench the rootball with the dilution. With deciduous trees the effect of the systemic is perceptible within a day or two in warm sunny weather, which is seen in the fast translocation from the roots to where things are nibbling or sucking on the foliage above. It will work for aphids and adelgids on a pine or juniper as well, it just takes about 5 days for the slower translocation of those trees before you see dead insects. Try spraying the tree with the product at the same time as drenching the soil.
If you’ve a small bonsai collection definitely consider applying any pesticide only when you see a problem. The fewer poisons, especially long-term poisons, we have sitting around in soil and in the tissues of plants the less problems we’ll have with other beneficial insect life. Although very fugitive in sunlight, these chemicals can last a long time when underground or in plants. Prophylactic spraying should be reserved for larger operations, perhaps using different chemicals, and again not around flowers that might attract bees.
I felt commentary on Bayer to be important not because I’m specifically endorsing it, but because it’s so readily available and so many of us are using it that awareness of its limitations and dangers would be helpful. Anyone who wishes to comment on their experiences are certainly welcome to do so (especially chemists and entomologists!)
(COMING SOON: Post of the first Portland Bonsai Village tour!)