Killing with CO2

Unsuspecting Aphids – Little Did They Know…

We were given a plant this summer that we are experimenting with keeping alive over the cold season despite our low light winter conditions and cool temperatures. Mysteriously it all of a sudden got aphids recently. I hadn’t seen any sign of them and then suddenly there would be many. Aphids are one of those insects that can reproduce asexually so it only takes one invader. I’ve always wanted to try killing something with CO2. This seemed like the perfect opportunity.

House Plant in CO2 Bag

Specifically I wanted to try killing aphids as I had a bad infestation decades ago in a greenhouse that I had not been able to satisfactorily resolve since I wasn’t willing to spray with pesticides. Then for decades I haven’t had an infestation so the opportunity for genocide has not presented itself.

Ladybugs do an excellent job but I did not want them crawling in my bed or elsewhere inside the cottage so that option was out. I bagged the plant and placed baking soda in the bottom of the bag. After sealing it up with just a small opening for pouring in we added vinegar. This produces CO2.

The result was the death of many of the aphids. I could see dead bodies floating in the fluid below the hanging plant. After taking off the bag we found very few living aphids. We’ll do a rinse and repeat and see if we can kill off the entire population with rising CO2 levels. This may be the organic solution to infestations. Perhaps it could be used on much larger scales.

Outdoors: 14°F/-4°F Partially Sunny
Tiny Cottage: 65°F/60°F

Daily Spark: Did you know that all four of the components used in Monsanto’s herbicide Glyphosate a.k.a. RoundUp can be commonly found in most American family homes? Shockingly three of these are used in the manufacturing of high explosives such as C4 while two of them are used in the Dihydrogen Monoxide which kills innocent children every year. One of these compounds was the cause of the terrible Hindenburg disaster. If you care, stop using Phosphorous, Nitrogen, Hydrogen and Oxygen. [Ref: 1, 2, 3, 4]

About Walter Jeffries

Tinker, Tailor...
This entry was posted in Uncategorized and tagged . Bookmark the permalink.

18 Responses to Killing with CO2

  1. Cary Howe says:

    I had thought of trying it with dry ice but the baking soda is more practical. Insects are really hardy so a few lived. Curious how long you left them before checking for survivors? Unfortunately doing it on a greenhouse scale even with baking soda may be impractical. I’d love to know the concentration of CO2 that’s toxic to insects? My guess is it’s 4X as high as mammals and maybe even higher yet. Trying to keep a concentration of 5% or 10% is going to be tough for a structure that isn’t air tight and if you need 20% I have my doubts. For individual plants I can see it being a solution.

    One thing that’s rarely tried is more than one solution at the same time. The point is the CO2 will weaken the survivors so using even just soapy water or add in some Neem Oil could finish them off. I’d try spraying them then do the CO2.

    You’ve got me curious because I had some indoor ground cherries that spider mites killed. You can’t get rid of them but CO2 could help with controlling them. I’ve been hesitant to try them or small tomato plants indoor since they get infested before the fruits can form. I also tried Pear Tomatoes indoors but I got a whole two tomatoes before the spider mites killed them.

    • The bag was on for two days. I checked for survivors first looking through the plastic of the bag which is less than ideal as it is not perfectly clear. At this point we’re watching the plant to see if we have a resurgence of the population post CO2. Let me know how it works on other populations with a comment here and we can collect together a list of options.

  2. Pam R says:

    Here scale is the problem. I’m going to try this on the scale. How long was the bag on the first time?

  3. Jeremy says:

    I was researching fire ant remedies and found one similar to this. A site recommended pouring a gallon of soda water down the ant hole, and the denser CO2 would sink down the hole and kill the whole colony.

    Now I’m just waiting for the opportunity to try it…

  4. Servius says:

    I wonder if this could be done as a preventive measure when purchasing used clothing to avoid bringing bed bugs into your house.

    • A most interesting and fascinating idea. Heating the cloths also kills bed bugs. We buy cloths at salvation army and then we take them straight to the laundry mat to wash and dry them before they come home in a different bag as a way of preventing the bed bugs from joining our household.

      • Servius says:

        Quick calculation. A gallon of CO2 gas weighs ~.015 pounds.

        50 Gallons then would weigh ~.75 pounds so any container less than 50 gallons could be treated with 1 pound of Dry Ice. There are warnings not to make the container airtight as it might explode.

        Looks like dry ice costs ~$1-$1.50 a pound, not including shipping etc.

        Do you ship with dry ice?

        • The problem is the closest dry ice is two hours driving to get it and we lose several pounds in transit and the minimum is five pounds. Dry ice is also $2.50/lb here as we’re further out on the supply chain. Add the gas and it gets very expensive. at $72.50. Plus two hours of our time which is another large cost as we have other things to do. Could back haul it but the dry ice place is about 20 minutes off our regular route so it is inconvenient. Could get it when we’re getting dry ice for shipping anyways but I’m working at eliminating that with the So-Low which goes colder than dry ice at -121°F – but no CO2 there…

          Baking soda and vinegar are cheap and on hand plus they both store well.

  5. Laszlo says:

    Inspiring post! If you choose a smaller bag or have the plant closer to the bottom of the bag, you might be able to increase the efficiency. Because Co2 is heavier than O2, the CO2 concentration at the bottom of the bag will be always higher. Though, I do not think that the bottom is completely filled with CO2 only, but you might get a high enough concentration to produce a better kill rate or the same one in less time. Additionally, if you want to check the CO2 level, you might want to fill a spare balloon with some O2 or less denser gas (than CO2) and put that inside, too. It should levitate and so roughly indicate the CO2 level.

  6. Sally Sievers says:

    I’ve been waiting to try this on the scale insects on my rosemary plant, till I heard how it came out. (Also, what ratio of baking soda to vinegar is optimal, or did you just pour?) So, publish the results of the experiment?

    • It was very effective. The first pass killed off all the aphids in the bag that I could see, the plant remained aphid free for a while, some that I think were outside the bag and in the house then recolonized the plant. We repeated the treatment with the CO2 and have not seen any reinfestation since. I would rate it a success.

  7. Pam R says:

    Am going to try it today on a wandering jew that’s badly infested, so we will see…

  8. Tim says:

    “I hadn’t seen any sign of them and then suddenly they’re would many.” I think it should say “… there were many”.

    Also, “Ladybugs do an excellent job bug I did not…” ; “bug” should be “but” ; not ladybug but the second “bug” in the sentence.

    This is a clever solution I will have to try. I repotted a plant recently in order to alleviate a gnat problem.

  9. Farmerbob1 says:

    Walter, the sidebar on this page is a bottom-bar. It appears as if it’s a different size from normal page sidebars, and is being pushed below the page comments.

Leave a Reply to Cary Howe Cancel reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.