How Can I Keep Wasps and Hornets Away From Fruit Trees and Gardens?

Ripe and fallen fruit is one of the strongest late-season attractants for foraging wasps and yellowjackets, since it's an easy, concentrated sugar source right when natural food elsewhere is starting to run low. In southern New Hampshire (Manchester sits in USDA hardiness zone 5b–6a) that pressure peaks across August and September, when colonies are at their largest and orchard fruit is dropping heavily, and it doesn't ease until the sustained cold after the average first hard freeze — around October 19 by National Weather Service climate normals. Extension guidance treats prompt harvesting and regularly clearing windfall from the ground as the primary, evidenced control step — not a spray, not a plant, just removing the thing that's drawing them in.

The popular idea that planting marigold, citronella, eucalyptus, or similar species around a garden keeps wasps away traces back mostly to garden and pest-company content, not entomology research. Peer-reviewed studies do show real repellency from the concentrated essential-oil compounds in some of these plants, but a living, intact plant releases those compounds at far lower concentrations than a dispenser or spray — nobody has shown that's enough to measurably change wasp behavior in an open garden. It's not harmful to plant them, but don't count on it as pest control.

Harvest and clear windfall fruit consistently through the season rather than letting it accumulate, and treat any scent-based approach as a minor supplement, not the core plan, if you want to add one. Neither of these steps addresses an actual nest if one's nearby — for that, /wasp-species can help confirm what's there, and /top-diy-methods covers what's realistic to do about it by species.