I was planning to plant several dwarf mugo pines this spring. However, 2 of neighbors just had mugo pines removed due to extensive sawfly infestations. Is this something I should be concerned about? How prevalent is this problem?
Hennepin County Minnesota
Thank you for the question. Mugo pine are a favorite host for European sawfly so monitoring for their presence is going to always be important if you plant this pine. Plants that are healthy and planted in the correct place (which means full sun for this species), with enough room to accommodate its mature size, and well watered during establishment will always have the best chance at resisting infestation and recovering if infested. We don't know how likely it is that your new shrubs will have a sawfly problem. If your neighbor's trees have been removed, that means the eggs that overwintered in the pine needles are gone too, greatly reducing the potential sawfly population but adults can fly so future infestations can come in from elsewhere. No plant is insect or disease immune. Regular scouting for problems and early intervention can keep many plants in good shape for many years. Read the following publications from the University of Minnesota and Penn State: