My front garden plants are always attacked by insects that eat through the leaves, with the plants sometimes losing about 80% of leaves. I don’t know what kind these insects are, but I’ve included a photo. This occurs on a yearly basis, some years worse than others. This garden is facing northwest and is under full sun from noon till sunset. There is a mature little leaf Linden tree about 7meters away. The soil is full of roots (there is a big stump 5 meters away), dry and hard ( primarily clay). I live near Centennial Park in Etobicoke and have been here for about 7 years. I noticed my neighbours’ plants’ leaves do not have holes like mine do. Is it something in the soil? Do I need to dig up everything and change the soil to remove the insects? The peonies, hostas, and shrub rose are not affected. Thank you for your help.
Thank you for contacting the Toronto Master Gardeners regarding your front garden perennials. It is always difficult to say with 100% certainty what is pest might be eating plants. That being said, Shasta daisies are a particular favourite meal for earwigs. Earwigs actively feed at night, so looking with a flashlight, to confirm that they are the insect damaging your plants, and not some other pest, is important. We have responded to a previous question about earwigs. You can find good, detailed, preventative information HERE.
Another possibility is slugs, or snails, which also feed at night. The Toronto Master Gardeners have answered many questions concerning the control of slugs and snails. You can find all these archived posts HERE.