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Yellow Jackets in Greenhouse

Hello everyone,

I have a fiberglass greenhouse with top vents and sealable windows. In the past two weeks yellow jackets have been making their nest inside. I've knocked down their nest twice, but now they're back again in a larger quantity (about 6 large hornets). I can't really even go inside without them swooping down at me trying to sting me.
I'm looking for a natural way to get rid of them and keeping them gone, as I am growing organic plants inside and don't want to spray any chemicals.
Thanks for any help!

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Would a trap like this help?

[url=https://www.gardeners.com/Wasp-Traps/GardenPests_Mosquitoes,38-786,default,cp.html]wasp trap[/url]

It's just baited with sugar water, but it has a one way entrance so they can't get back out.

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Use the trap, but don't put it inside the greenhouse. You may draw more yellow jackets inside if you do.

You will have to continue to knock the nest down every time you see them trying to restart it. Eventually, they'll go elsewhere.

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Nest knocking is safest early in the morning when temp is lowest. Also this time of the year, baiting the trap with a bit of meat is effective because the larvae are carnivorous and they are trying to feed them.

If they were nesting in out of the way location, I would say let them stay because caterpillars are one of their baby foods, but not if they're not willing to share the greenhouse.

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Yes, bait it with meat. I've been so desperate to keep yellow jackets away from our (dog club's) annual June picnic that I've even bought...bacon...to bait the trap with (non-pork-eating household). My home-made traps caught over four dozen yellow jackets in about 3 hours.


1-gallon milk jug, preferably with cap
Scissors or utility knife
12"-long stick
raw bacon
dishwashing liquid (I used Dawn)

1) Cut a pair of matching holes on opposite sides of the jug towards its top. (Read these instrux all the way through to get an idea of a good size for the holes.) Squirt a bit of Dawn into the bottom of the jug, avoiding the sides, and follow it with water. If some Dawn did get onto the sides, strategically aim the water there. You're going for a solution of Dawn + water but not the suds, so pour the water slowly.

2) Cut a slice of bacon into three or so pieces. Small is good. Thread string through each piece of bacon such that you can hang the string from the stick inside the jug, but the bacon won't touch the Dawn + water. THIS IS CRUCIAL.

3) Carefully hang the jug away from the reach of children or curious cats or boisterous dogs. Use more of that string through the jug's handle and secure the handle to...a branch, a crossbeam, an angle reinforcer. Reasonably near where you've observed these yellow demons in flight.

4) How it works: Yellow jackets are attracted to the meat. We couldn't keep them away with sticks from a bucket of fried chicken at the picnic the year before I made these traps. :evil: But the fruit salad was virtually untouched. :idea: Bait the traps with meat. :twisted: Once the yellow jackets eat the meat, their instinct is to drop down and then fly away. AHA! That dropdown is what you're waiting for: that's when they contact the Dawn + water. They can't get back out. (Keep the cap ON the jug; don't give them additional means of escape.)

The bottom of one jug had so many yellow jackets that it was pretty much covered with them. :shock: People and dogs were greatly relieved. :D

Cynthia H.
Sunset Zone 17, USDA Zone 9

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Re: Yellow Jackets in Greenhouse

I take it you're not talking about Bumble Bees (which generally nest in the ground and can be put out of business with a garden hose).

(Believe it or not)

Here are a number of things suggested by WIKIHOW to deal with exactly this!


~ I particularly like the way they describe making a trap out of an old soda bottle.

They seek out protein and sugars - including the protein in pet foods, so you may want to avoid having pet food out of doors. Feed them in the house exclusively. Sugar water may serve well as a bait for the trap they describe too

WASP = Weird Antisocial Stinging Pest

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Re: Yellow Jackets in Greenhouse

I know this is old but there is one tried and true method of eliminating nest building wasps. Just removing the nest never works because they have a homing instinct which brings them right back to the spot they've chosen. The only way to stop the nest building is to kill the new queen that is building the nest. This is best done early in the morning just after sunrise when she is guarding her little nest.

The ones that aren't in really bad locations I leave alone. One year I watched a whole bunch of them eating and carrying away sawfly larvae that were devouring my currants.

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