PESTICIDE RECIPE: The Best Bug-Killing Mix for Mealybugs, Aphids, and Thrips on your Orchids (Works well for other house plants too)

In Orchids
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If you’re dealing with mealybugs, here’s a good post to pair with the below pest spray. And this post from First Ray’s gives a good generic overview of mealybugs.

I don’t use systemic pesticides – they are not available for consumer purchase in Canada (save the bees, right?) so it’s not an option. Also, I grow plants exclusively in my home…systemics are not something you want to be breathing – and if you smell it, you’re breathing it. If you still don’t care about systemics and just want to get rid of the bugs (even if that means killing the bees), then you have lots of options to choose from, but you wont find those here.

Test this home-made bug spray first

Before you go spraying ALL of your plants with this mix, you may want to test it on your plants. Also, know this: orchid buds and blooms do not do well with alcohol or soap on them. I lost a giant spike on my Phal. Malibu Madonna that had over 20 flowers on it when I sprayed—all of the flowers: DEAD. I’ve also had a few non-orchids get leaf burn from this spray…but they recovered (and honestly, it’s the only thing I’ve found that actually works against aphids and mealybugs).

Ingredients for the Best Bug for Killing Pesticide
(Kills Mealybugs, Aphids, and Thrips)

  • 1 Cup of Water
  • 5 drops of Blue Dawn Dish Soap; not sure why the blue version is specifically called for, but it appears that everyone on the web says THAT is the one that works best (and it worked for me, so I’m not arguing it).
    • Alternate soap: 1/2 tsp – Dr. Bronner’s Peppermint Soap – after hearing the value of this from a few sites and from Glen Decker from Piping Rock Orchids, I started using this and love it.
  • 25 drops of mineral oil – I use baby oil; I have heard of many people substituting Eucalyptus and/or Cinnamon oils in place of this – I intend to try this.
  • Optional: Some people use 1/2 ratio of isopropyl alcohol to water – I didn’t find it helped and that the oil & soap is what suffocated the insects rather than the alcohol which is reported to “dry them out”

Added Oomf / Additional Bug-Killing Power

Substitute these drops for the mineral oil – you can use a combination of all; but your goal is around 20-30 drops total per cup of water.

  • 10-20 drops Neem Oil
    (from healthfood stores in the “pills + skin section” – because they dont sell neem oil in Canada for some reason)
  • 10-20 drops of Cinnamon oil / extract
    (from Walmart)
  • 10-20 drops of Eucalyptus oil / extract

Directions for Applying this Home-Made Pesticide to Infested Plants

In a spray bottle create a mixture of the above ingredients. Shake it up, mix the soap and ingredients around, then spray the aphids/thrips/mealybugs and really well. You want to cover them in it. Soak the top and bottom sides of all the leaves (it’s okay if it gets into the substrate/soil). Let it sit for about 5–10 mins. Spray again liberally; wait another 5 mins then take them to the shower (or sink) and spray all the leaves with clean water; let the water run through the potting mix for a while too to rinse out any soap.