As it’s growing in challenging conditions, the round boxwood (Buxus) planted by my front door has always been plagued by boxwood psyllids (Psylla buxi). They’re the tiny sucking insects that cause the tips of boxwood leaves to deform into cups. Unless you looked closely at your box foliage, you might not even realize that this cupping is a deformity. It is.
Right now, these little bug-ers are visible, disguised by the fluffy white threads you can see in this picture. Now’s the time to spray, before the nymphs take refuge in those cupped hideouts.
Yet, as of Earth Day, April 22, 2009, the Ontario government has put into place some tough new regulations about what you can, or cannot, use to do this (or to control any pest) for cosmetic reasons in the home garden. You should be aware of these new rules. And they’re somewhat confusing.
For instance: Psyllids can be controlled by spraying with insecticidal soap about now when the buglets first emerge from the eggs. However, some insecticidal soaps contain pyrethrins, an organic and previously “green” compound that is now on the banned substances list. That means, if it contains pyrethrins, don’t try this at home.
Just because you can still buy a product on store shelves, don’t assume it’s okay to use on your home garden. Products with banned substances may be available for sale, for use by certain professionals (such as farmers or golf turf pros) OR for use by you but for non-cosmetic purposes. That means, you might be able to use a certain bug spray inside your home, to control carpenter ants, but not the same spray to control ants outdoors.
Best to be informed. Check out the Ontario Ministry of the Environment website to download the PDF factsheets for home gardeners.
By the way, you are also not allowed to use up any banned products you might still have on hand. They must be safely disposed of at one of the City’s hazardous waste depots.
So, I’ll be using plain old insecticidal soap on my psyllids, without pyrethrins (or horticultural oils — another new no no). Hopefully, I’ll catch the bugs in time to zap them, legally.
If only I had something to help my boxwood fight that other dread disorder: death by flyer guy.
Great advice and info here, thanks for posting this!
As for horticultural oil, I am going to try vegetable oil in its place next year when I spray the fruit trees. I’m sure it will perform the same physical action of suffocating the insects, but how “sticky” it turns out to be, and how important that is, remains to be seen. I may try some safers soap in there too, to increase adherence.