Insecticide Spray Application on Linden Trees For Aphids - November 2020
A week or so ago, I posted about how our pair of espalier Greenspire Linden trees had come down with an infestation of aphids . I asked the Master Gardener at the University of Illinois and they confirmed they were Linden Aphids and recommended a synthetic insecticide. They also pointed me to this post from Colorado State University that lays out the two types . Persistent Contact Insecticide Sprays. And Systemic Insecticide Sprays. First the latter: systemic. These are ones that 'move through' the tree and can handle aphids that you can't reach with a topical/contact spray. From CSU: A few types of insecticides have the ability to move into the plant and move systemically. Because of this mobility these systemic insecticides can provide better plant coverage and often provide better control of aphids than do non-systemic insecticides. Systemic insecticides are also able to kill aphids that are protected within a leaf they have curled. Timing of application is also