We have a hedge around the house which looks like boxwood, I have recently noticed some black spots and holes on the leaves, as well as ants and some other bugs, as you can see the photos. I was wondering if you could identify the hedge and also the leaf disease.
Located in north west of scarborough, clay soil, hedges facing south, full sun exposure.
Your hedge appears to be privet (Ligustrum vulgare or perhaps another cultivar), not box (Buxus spp.) whose leave are rounded. It has certainly undergone damage by insect pests.
Although privet is generally considered to be resistant to serious insect pests, occasional infestations may occur. The insects you have photographed in the top right and bottom left photos do not seem to be ants, although the bottom right hand photo does show an ant. There don’t appear to be any signs of sooty mold on your hedge leaves, which would be consistent with aphid or scale insect infestations. While ants don’t themselves chew holes in your leaves, they are often to be found when other insect pests are present – they are attracted to the sticky residue known as “honeydew” which certain pests such as aphids produce. If it is possible to send us a close-up of the insect, we will do our best to make a positive identification. However, even without knowing exactly what type of insect is causing the damage, here are some options for control:
- Spray your hedges with a strong stream of water using your garden hose. This will knock the insects off the leaves, repeating every two or three days;
- If you can visually spot any branches that are very heavily infested, prune and destroy the cuttings;
- Consider using insecticidal soaps or horticultural oils which will kill the insects present – any large garden centre can help you to choose one of these products.
If this is a large, well-established hedge and the above suggestions seem daunting, you could consider calling in an arborist for a professional opinion and treatment. To find a certified professional arborist, Landscape Ontario maintains a list by geographic area – just choose ‘arborist’ from the drop down menu: https://landscapeontario.com/