How Can I Keep Wasps Away From Outdoor Picnic Setups?

Keeping food and sweet drinks covered, using lidded cups instead of open cans, and cleaning up spills and scraps promptly removes the cue that draws foraging wasps in the first place. Extension sources are consistent that this is the highest-leverage step for an outdoor gathering, well ahead of any spray or scent-based product, because late-summer wasps are actively scavenging for exactly the sugar and protein a picnic offers. In southern New Hampshire (Manchester, USDA hardiness zone 5b–6a) that scavenging pressure peaks across August and September, when colonies are largest, and holds until the sustained cold following the average first hard freeze — around October 19 by National Weather Service climate normals — so a late-August cookout is precisely when covering food earns its keep.

Wasps are drawn to the concentrated sweetness inside an open can and will crawl in, which creates a real risk of a sting to the lips or inside the mouth if someone drinks from it without noticing. Extension guidance specifically calls out covered cups or straws over open cans for this reason, separate from the general food-management advice.

A lure trap placed well away from the gathering — extension research cites a study that meaningfully reduced yellowjacket presence by ringing a picnic area with traps roughly 200 feet out — intercepts foragers before they arrive. A trap set near the table does the opposite, pulling more wasps toward the people it's meant to protect. If wasps keep showing up despite good sanitation and trap placement, that can point to an active nest nearby rather than just general foraging, which is a different question covered elsewhere on this hub.