Do pests ruin landscaping or decorative plants?

The great majority of what homeowners notice on ornamental plants — stippled leaves from lace bugs, honeydew and sooty mold from aphids, skeletonized foliage from Japanese beetles, a season of caterpillar tents — is cosmetic. Per University of Minnesota Extension, adult Japanese beetle damage usually affects only the appearance of plants, and healthy, mature trees and shrubs tolerate a lot of feeding without significant, long-term injury. That's the honest baseline for this entire category: an unsightly plant in July is very often a completely normal plant again by the following spring.

A defined minority of landscape pests genuinely can kill a plant, and it's worth naming them precisely rather than treating the whole category as equally risky. Active wood borers tunnel into stems and trunks and cut into the tissue that actually moves water and nutrients. Heavy, sustained scale infestations can do the same over time. Repeated (two or more consecutive year) defoliation by the invasive spongy moth or winter moth depletes a tree's energy reserves faster than it can rebuild them. And voles girdling the bark at a young tree's trunk base, often hidden under winter snow, can cut off the tree's circulation entirely. These four are the genuine exceptions — everything else on this page is the cosmetic rule.

Correct identification is the single highest-value step: it tells you immediately whether you're looking at the cosmetic majority (do nothing, or give the plant basic care) or the lethal minority (call in help before the plant is lost). Either way, the actual fix lives in horticulture and arboriculture — UNH Cooperative Extension, a local garden center, or an ISA-certified arborist for a valued tree or shrub. None of this touches a home's structure or systems, and treating it as a pest-control matter to justify a service call would be exactly the overreach this hub exists to call out.