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Home made bug spray

10 years ago

I have a neighbor that is trying to kill bugs in her garden and tried a soap based mixture. She said it killed the bugs but also killed the lady bugs and she did not want to harm the honey bees. Is there a mixture that will kill the bad bugs and leave the good ones alone? She has a large garden and a limited amount of time to devote to it since she has 4 children. She tries to squash them by hand but that gets old in a large garden when its 100 degrees. Any solutions?

Comments (3)

  • 10 years ago
    last modified: 10 years ago

    What is she growing? What does she want to kill? BT, for caterpiilars wont hurt anything else. But most everything else is going to impact beneficials the same as baddies. I think they say spray late in the day to avoid bees. Kind of late to do trap crops, which you allow to become infested and then dispose of or hand pick from them instead of the whole garden. Spray aphids off with a strong stream of water. I guess that might help for early stages of spider mites, but who sees EARLY stages of spider mites? I was googling help for spider mites and came across someting on a pot growing website (well, pot gets them, too) it's a leaf wash. SMC I have no idea if it works or not. Web site makes it SOUND good.

  • 10 years ago

    As far as I know, there is no insecticide that kills all the bad guys and none of the good guys. It just doesn't work that way. If we had a room full of people and half of them were good guys and half of them were bad guys and somebody evil sprayed a toxic nerve gas into the room, would only the bad guys die? Nope. Well, it is pretty much the same in the insect and mite world.

    Most pest insects that we see in the garden will be controlled by beneficial insects if we just leave them alone and let them do their work. This does require patience, and it is not a 100% solution.

    I'd say that 100% of the insect and mite damage in my garden is done by less than 3% of the insects in the garden, and I'm not willing to kill the other 97% just to get that 3%. I've been gardening all my life and have sprayed my garden once and only once with a broad-spectrum pesticide and I hated everything about it, except it did stop the grasshoppers from eating my tomato plants down to bare, naked stems. Was it worth it? Nope. Looking at the aftermath in the garden, I don't believe I'll ever do it again.

    If you can tell us what specific pests are a problem we can recommend a solution. Some people will say Spinosad is the solution, but there are questions about its effect on some beneficial insects, so in my garden I only use it as a granular bait product that must be injected by the targeted insect in order to be effective. It also is known to be highly toxic to bees, but less so to lady bugs up to a point. Spinosad is largely harmless to beneficial insects who are carnivores because they feed on other insects, not on plant matter sprayed with Spinosad. However, lady bugs feed on pollen and bees feed on nectar, so the thought of them feeding on plants just sprayed with Spinosad bothers me. Normally, the plants would be largely safe for lady bugs after the Spinosad has dried, but then if the lady bugs feed on pollen that was sprayed, then what becomes of them? What happens to the bees if they nectar on a plant with dried Spinosad on it? How well has this been studied and how well is it understood? These doubts lead me to avoid using Spinosad as a liquid spray in the same way I would avoid any neonicotinoids or other synthetic pesticides. Spinosad is both a contact killer and an ingestable killer, so to me that makes it more toxic than its "organic" category might seem to indicate.

    In some cases, permethrin perhaps could be used on certain insects. Much depends on what the problem insects are.

    If you can tell us what specific insects she has in the garden, we may have specific suggestions for specific narrow-spectrum pesticides (like the Bt "kurstaki" that works on caterpillars on the Bt 'israelensis' that targets mosuitoes) that might be less harmful to non-target insects. There's no easy one-size-fits-all broad-spectrum solution that will not also kill some or all beneficial insects, and here is one example: people will spray Sevin in a misquided effort to kill spider mites. It is not very effective at killing them, but it does kill the beneficial insects that are helping to keep the spider mites somewhat under control. Then the spider mite population further explodes because whatever beneficial insects were helping control them are now gone, so the result is that the gardener has done something that will give them more spider mites, not less. My dad learned this the hard way in his garden long, long ago, and since those days, university research has documented the same thing. This is an example of why we must very carefully evaluate each pest that is causing a lot of damage and target a control to that specific pest.

    There are some products that are not insecticides that can help, like Surround WP and Garlic Sprays (or homemade garlic-hot pepper tea sprays). Some people use neem oil for a wide array of damaging insects, but great care must be taken when attempting to use neem oil in hot temperatures (90 degrees or above) as it (along with many other products containing oil) can fry plant foliage when used in hot weather. Some permethrin products are fairly effective, but certainly not non-toxic, and I wouldn't use them in a garden that cats visit.

    There's no easy answers, no quick and simple solutions. Everything we use in the garden has the potential to be harmful to something we're not targeting, so we have to be really careful in the choices we make.

  • 10 years ago
    last modified: 10 years ago

    ok, I will get with her and find out what bugs are bothering her and come back. I was hoping for a garlic/hot pepper spray that was good and didn't kill the beneficials. I told her that it would take several years to build an eco system to where good bugs outweigh the bad. Like building bird houses and birdbaths for birds to come to their garden. Also planting certain plants like dill and parsely that good wasps like. She will have to work on it but she is willing and I like the fact that she is concerned about spraying poisons and killing our good little bugs