This spring I've had an outbreak of aphids in my indoor plants. I've been spraying with Safers Insecticidal Soap. I have been spraying weekly for over a month and they keep reappearing. I'm wondering if aphids are becoming resistant to this product. I prefer to not use any chemicals if possible. Since the soap doesn't appear to be working I'm now trying Neem oil but am not sure if it is effective against aphids. Any suggestions would be appreciated.
Complete coverage is the key to getting ALL the pest when spraying plants. You want to get every inch, spraying under the leaves as well. if you miss any, they will come back. I would also suggest just plain water from a garden hose if you have one (med velocity) something I did with one of my sisters plants that had a LOT of Aphids.The water works simply knocked them off their perches! Then my sister did the same thing with the hose a couple more times just to be sure. You can tilt the plant some outdoors so you don't keep soaking the soil
You might want to try some of the basic dish soaps; they've worked for me before. I've used Sunlight dishsoap and it did the trick (nearly killed the plants, but it killed the bugs). I tried some 7th generation dish soap but it was too mild to kill anything. Good luck
careful with dishsoap, they may contain ingredients designed to strip oils and other things which plants need on their leaves. If soaps alone arent effective try one with pyrethrin and / or canola oil as well, such as Safers 3 in 1.
Thanks for the suggestions. I've been avoiding going to something stronger but I may have to. I'll check out the Safers 3 in 1.
Is it possible that your're using an old bottle, either one you have had too long or one that sat on the store shelf too long? Some products can lose their effectiveness as time goes by. I have noticed some things at my local garden center have been sitting on the shelves for years.
You're right about some products going out of date. I contacted Safers to ask that question and apparently insecticidal soap has a shelf life of 3-5 years. Unfortunately it doesn't state that on the product. So, that may have been why it wasn't effective. So, it is probably a good idea to write the date on the bottle when it is first used. I'm assuming that 3-5 years is from first use and not when it was bottled but I'll check on that.
For smaller house plants that have any type of bug that I just can't seem to get rid of, I take the plant out of the pot, shake the dirt off the roots, and soak the whole plant in a sink full of water with dish soap. Soak it there for a while (that will kill the aphids) then, when you remove it from the soapy water rinse it well to get rid of any and all the soap. Replant it in new, clean soil, in a new, clean pot - not the old pot and soil that still may have an aphid or two hiding, waiting... I do this when I have no luck with any commercial product and the plant is suffering.
I would say thats not the easiest solution. If certain plants regularly have infestations of insects they are usually stressed by other factors and weakened to the point where they become susceptible. Find what is wrong with the growing conditions and change it, or get different plants that are better suited to the growing conditions would be more long term solutions.
You might consider organocide. It's a sesame and fish oil product that works VERY well. I have had 100% success with control of aphids and whiteflies in my greenhouse alternating between the oil and the soap. After three weekly oil treatments, I wash them thoroughly with safer soap. This plus some fertilizer made my plants very happy! Be sure to use gloves, though, they're not kidding when they say "FISH" oil!!
The organicide sounds very interesting. I will have to see if it is available in Canada. I have also received more information from Safers re: shelf life of insecticidal soap. It is 3-5 years from date of manufacture. So I imagine that many people have bottles sitting around that are out of date. I have suggested to their customer service person that the bottles should carry an expiry date.
