Use Decoy Plants to Trap Harlequin Bugs

Passing Knowledge Across Generations

The other day you all said that somebody wrote in to ask for help with harlequin bugs. I grow lots of broccoli so I despise those little suckers too. I have one little trick that I do, and I thought I should share it with you since someone else shared it with me. It’s probably too late for this season, but this might help you out when you get started next spring. The trick is to use what I call my “decoy plants.”

I learned this from my Mother, who taught me most everything that I know about growing plants. She learned everything the hard way. She spent all her spare time out in the garden through years of Oklahoma summers as far back as I can remember. Through trial and error, she picked up on several little tricks and shortcuts – and I was just lucky that she handed some of those tricks off to me before she passed along.

Using Decoy Plants to Trap Harlequin Bugs

The basic idea here is that you think ahead, and you put a few of your broccoli seedlings in pots instead of putting them in the ground with the others. I start all my own plants from seed, so I just choose the worst looking seedlings and I use those ones. I suppose you could do the same thing if you buy your seedlings – just pick a few that don’t look as good as the rest and put those ones in the pots.

I use whatever old plastic pots I have lying around – the size shouldn’t matter too much so long as it’s big enough to keep a broccoli plant alive for several months.

The plants in the pots won’t look as good as the plants in the ground, and they won’t get as big either – but that’s the whole idea. You want to just barely keep them alive all the way up until it starts to get real hot, which is when those little harlequin bugs tend to show up and ruin things.

Read more: Everything You Need to Know About Growing Cole Crops (Brassicas)

How to Spring the Trap

Once the weather starts to get hot, situate your decoy plants all around the area best as you can so that there’s one within just a few feet of all your good broccoli plants in the ground. For some reason, those harlequin bugs will jump on the decoy plants rather than eating your good plants. My Mother thought this happened because the suffering decoy plants smell different from the happy plants in the ground, but who knows?

Now as soon as you start to see harlequin bugs on the decoy plants, that’s your “kill zone.” Start spraying them once or twice a day with a fine mist of soapy water. Once the bugs arrive and you start spraying, those decoy plants will go downhill real fast. But they buy you some time to keep harvesting from your good plants until the bugs move along to start eating those ones too. And you’re spraying them with soap all the time, so it helps control the infestation for a little while anyway.

Decoy Plants Aren’t Fool Proof

Some years this works better than others. I’ve had years where the bugs ignored the decoy plants and went straight to my good plants. I think it might have had something to do with the variety of broccoli I was growing at the time.

Other years, I wasn’t able to keep the decoy plants alive long enough and they gave out from heat or lack of watering before the harlequin bugs arrived. But most times the decoys work and I believe this helps me to extend the tail end of my growing season in most years.

Read more: How to Properly Store Your Garden Sprays, Potions, and Powders

Some Final Words of Wisdom

One thing I’ve learned on my own that might help you out is that at the end of the day, there’s just not too much you can do. If you try to grow your broccoli too late in the season, you’ll eventually lose that fight. Start your broccoli and cauliflower early, and keep some new plants coming until it starts to get too hot. When the young plants start to bolt early and the bugs start really moving in, it’s time to call it quits for the year.

Just cut any remaining plants off at the ground and cut your losses, so to speak. You can still make use of the leaves and stems. And once those broccoli plants are gone from your garden the harlequin bugs will probably just disappear.

Sometimes I can squeeze in a second planting for the fall here in zone 7, when there aren’t any harlequin bugs to speak of. For fall plantings, be sure to get yourself the fastest variety you can find. The last few years I’ve had good luck with a variety called Bonanza. Burpee says they’ll be ready in 55 days – I don’t know about that, but they do grow fast enough to get us a decent fall harvest, so you might try those. Good luck to you.


Thanks to Jerry Schraeder for participating in the [Grow] Network Writing Contest.

We’re still getting the list of prizes lined up for the Spring 2016 Writing Contest. We awarded over $2,097 in prizes for the Fall Writing Contest, including all of the following:

– A 21.5 quart pressure canner from All American, a $382 value
– A Survival Still emergency water purification still, a $288 value
– 1 free 1 year membership in the [Grow] Network Core Community, a $239 value
– A Worm Factory 360 vermicomposting system from Nature’s Footprint, a $128 value
– 2 large heirloom seed collections from Baker Creek Heirloom Seeds, valued at $103 each
– A Metro-Grower Elite sub-irrigation growing container from Nature’s Footprint, a $69 value
– 2 copies of the complete Home Grown Food Summit, valued at $67 each
– 3 free 3 month memberships in the [Grow] Network Core Community, valued at $59 each
– 4 copies of the Grow Your Own Groceries DVD video set, valued at $43 each
– A Bug Out Seed Kit from the Sustainable Seed Company, a $46 value
– 4 copies of the Alternatives To Dentists DVD video, valued at $33 each
– 4 copies of the Greenhouse of the Future DVD and eBook, valued at $31 each

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  • I have joined several times to get free ebooks but somehow I never get access to the books. So what’s happening?

    1. Michael Ford says:

      Hi Sylvia – Sorry you’re having trouble. Give us a little time to look behind the curtain – we’ll sort it out and get back to you – Michael

  • MarjoryT says:

    Nice post! My thinking is this: insects are the predators of the plant kindom (for the most part). And the purpose of predators is to take out the weaker of the species. So intentionally goro0wng weak plants to sacrifice makes sense. To demonstrate this, an old man I once knew showed me a row of squash plants he was growing. One plant ont he end was weak and covered with bugs. The rest of the healthy row was untouched.

    Why do they sometiem takes the entire crop? My best guess is the entire crop is weak or missing in some viatl nutrients.

  • Carol says:

    Since we love tomatoes & have one bed dedicated to growing them, have found that interplanting basil also helps to reduce the no. of hornworms, as well as marigolds, but not totally eliminate them. Remember, hornworms travel in pairs & you may need to hunt to find its friend, but make sure you eliminate an even no. of hornworms. I usually check the branches or underside of the leaves and hand pick them off before too much damage is done, but they have voracious appetites. We live in the desert (very hot & challenging to keep tomatoes alive during summer).

    While picking them off, I throw them into another area of our yard and the mockingbirds love to eat them. Whenever hornworms appear, the mockingbirds would wait for me to come out to the garden and throw them the hornworms. It was so cute to see mocking birds just waiting for their next meal. They just love hornworms! If the hornworm is too large, the mocking bird will eat half and fly off with the other half to its nest to feed its babies or mate! This is just another way to eliminate them, while feeding beneficial birds.

  • ClaudeA says:

    In about 1973 I began producing my own garden soil. As the years went by, I began to notice interesting results with my garden soil plants. Those years I had a good nutrient base – such as years I had access to lots of sea weed that went into the hot compost piles, the insects on the garden plants were much less. In time I began to put two and 2 together and with more research discovered that plants given all the nutrients they need to maintain health and resist disease, also produce toxic deterrents to parasite insects.

    The plants that do not have good root systems or grow in nutrient deficient soil are attacked by disease and bugs

    Go figure!

  • Sandy says:

    Your Mom was brilliant, and must have felt blessed to have a son who appreciated her!
    Where we are, summers usually stay below 90. We might get 2 or 3 days, not necessarily in a row, at those temperatures. At what temperatures would the harlequin bugs appear? I looked for pictures of harlequins, haven’t seen any in my garden, which is kept organic. BUT I am going to try Mama’s strategy on some of the other bugs that do show up, especially the grasshoppers, another warm weather pest that we do see here some years they have eaten every bean, some years not, especially the year that I planted only Anasa’azi beans. They nibble a few tiny ones and left the more developed ones for us. Anasa’azi beans grow like half-runners, and I may try those if Mama’s remedy doesn’t fool the grasshoppers.
    A strategy that does work for me is a remedy for aphid infestations farmed by ants. When I see them appear on cabbage family plants I will sprinkle a handful or two of compost around the base of each plant and water lightly. The aphids are always gone the next day. In my more organized years I apply compost every couple of weeks and save the ants (and myself) the extra effort.

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