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This topic contains 1 reply, has 2 voices, and was last updated by  E. Vinje 7 months, 1 week ago.

  • Insecticidal soap against aphids

    Created by Michael on

    I’ve been using liquid dishwashing soap diluted in water to spot treat my Helleborus plants. Now, on your website I hear of insecticidal soap, which I never heard of before. Does it honestly work much better? How is it insecticidal once dry?

    Do you recommend any horticultural oils to treat pests, like aphids and more, on evergreens, like rhododendron, Hellebores, and other such plants? Do you have a treatment regimen that most gardeners should follow to keep pests at bay, and keep the ecosystem of the garden well balanced?

    Any suggestions and recommendations would be appreciated.

    Thank you, Michael in East Hampton, NY (zone 7)

  • Author
  • #249257 Reply

    E. Vinje

    Hi Michael –

    The biggest benefit to using commercial insecticidal soap is that it has the best dilution rates for the most success in killing off pests along with the added benefit of sticking agents to make it more effective than your typical dish soap. Keep in mind, that we sell many natural herbicides that are made from the same ingredients —
    potassium salts of fatty acids — they’re just more concentrated and will kill plants as well as pests. Once the soap spray has dried, it’s ineffective.

    When it comes to a regimen to knock back pests and keep your garden healthy, I would suggest cycling through a couple of different products for best results. Aphids produce very rapidly so, building a tolerance is not uncommon. A pyrethrin spray would be advisable as that targets their nervous system and kills much more effectively along with an insecticidal soap to break down the membrane of the aphid. Applying these on a rotating schedule should prove to be a bit more effective. Diatomaceous earth can also be used against aphids. A mild abrasive, it kills insects within 48 hours of contact… indoors or out!

    Another option you may want to consider is to release ladybugs on your affected plant. These beneficial insects are happy to munch on unsuspecting aphids and help to clear up the problem.

    Hope this helps!

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