Why Neem Oil Doesn’t Always Work! The Science Of Neem Oil For Plants & Soil | Scientist Explains

This is a very late night upload sorry about that! YouTube took two days to upload this video for some reason. Anywhozers! If you want more info check out this article here! If you want to grab neem that is cold-pressed and would work here is your link geni.us/TBt77L I just looked at the major brand I see all over it is NOT cold pressed it is hydrogenated. gardeningincanada.net/why-does-neem-oil-stop-worki…

So, azadirachtin (the active ingredient in Neem) is supposedly translaminar, and can be extracted from the oil to varying degrees, as in the pesticides Azamax and Azapro. The problem is that, unless you are using those two tested formulations, you cannot guarantee the concentration of the active ingredient in Neem oil, and the cold pressed stuff just gives you a higher chance of it actually being present at a useful concentration. You're right that the active ingredient and the several others that are present in the oil itself basically make the plant taste bad (primary antifeedant), but also if they ingest it has toxic effects on the gut, meaning they eventually starve because they can no longer process food (secondary antifeedant). The bugs avoid the taste because it will kill them. The key is whether that happens before they lay eggs. Then the use of the soil drench becomes apparent because it basically affects the bond between their old and new exoskeletons and makes them molt too early. While it's not a great broad spectrum pesticide, it is one that is effective against spider mites and is safe enough for mammals to use around your kids and pets, though it doesn't smell great. I disagree with the preventative use, and I find that the key to using it as an insecticide is to make sure you are using it repeatedly through several lifecycles of spidermites (basically once or twice a week for a couple weeks). Once the spider mite battle is won, you can repopulate your soil microbes.

I was able to get 100% pure and organic cold pressed neem oil shipped to Canada but it must specify a usage that is not pesticide related. The product I bought from Oreola Naturals indicated that it’s for face, hair and skin. I have been using a mix of neem oil, rubbing alcohol and dish soap to fight a bad spider mite infestation in my hydroponic garden wall and it has been working. I see the odd egg cluster but everything else seems to be dead.

Thank you so much for the information. My key takes were "child pressed" and "resistance".

I agree with almost every word you said. In Italy we have access to neem as a product (neem oil without any way of knowing the % of active agent) and as a proper "pesticide" (product such as Neemazal or similar, with guaranteed 1% azadiractina A) so in the first case you will NEVER known what you are using exactly and in the second you need to be a registered user to buy (it's regulated like other pesticides), not just an amateur gardener. Anyway, there are just two things that I would like to add: 1) Neem OIL it's not useless by itself. In the worst case scenario it will work just as an agricultural oil of sort, problem is you are paying it more :D. 2) pH is very important to consider also for the water solution you're using to apply: alkaline pH destroys any azadiractina presents, so NEVER mix up neem with other product (soaps, limewater or whater) with an above neutral pH and if possible use rainwater for drench application.

I would love to see an episode on systemic pesticides. Thank you for all your knowledge you share !

I’ve tried using Neem Oil in a foliar spray. I’ve used just Neem & Water or Neem, Soap & Water. Having reconsidered since then, it would seem that I was fighting the effectiveness of both by mixing them together. Soap breaks down oils; in the process, the soap’s strength is lessened…? That’s my thought. I made sure to purchase cold pressed Neem with the Azadirachtin included (supposedly some cold pressed products sold have removed this effective ingredient to market separately. I don’t know but that’s why I specified that A was included). I’ve seen limited effectiveness using it. The buggies may have died, but the always returned in a few short days. I’ve a gardening acquaintance who used Neem Cake in his soil to combat harmful nematodes (the ones that cause root knot galls). He said he did see some benefit. He also however always works in worm castings. Since you are a soil specialist, do you have any data or information on that manner of application?

This video is incredible - I've been struggling with thrips for years, frequently using NEEM to no avail.

Your channel is gold in comparison to other unscientific YouTubers. Well, I am a graduated phytopathologist and your teaching is terse to the point. Hi from Germany and keep up the great work. Neem users seem to be caught in magic thinking when they don't use the cold pressed oil.

I'm very happy to have found your videos. I am in upstate NY and have access to Neem Oil but unfortunately last year I bought an organic garden product which only contains an extract of Neem and a very small percentage, not very effective at deterring pests. I am a soap maker as well as a gardener and discovered through my soap making research how beneficial cold pressed Neem Oil is for skin care and skin health. Azadirachtin has been used medicinally pre written history and is still a traditional medicinal staple. I have some cold pressed Neem Oil on the way for my garden and am planning on making some soap with it too, apparently it is great for skin issues, stinky but beneficial.

Wow that was super informative. Thanks for making this video.

Hi Ashley, I've been following your channel for a couple of months already, and I love the content of your videos. Today, I am here, since I discovered the reason for my stressed strawberry (sweet colossus) plug plants in pots, is the infestation of some tiny, whitish, translucent wormy larvae, residing around the base of the plant's neck. I have already pushed back the well rotted farmyard manure, but since the plugs are in 16cm pots, each, the plugs are still surrounded by the larvae. Instantly, my cold pressed neem oil came to my mind but I wasn't sure if using this solution in the soil would pose a danger to the plant itself. Perhaps might burn it or something. But, you have shared such useful information on this product. I know a little more about what I'm dealing with in terms of neem oil on plants and pest, than I did, before I watched your video. I always feel better equipped as a gardener whenever I watch your videos. Thanks for coming up with this channel. God bless you.

Thank you for this. I've been looking at neem products wondering if I should try them, and there's so much verbiage involved and marketing and hype it's hard to find real scientific facts about it. I have a small recurring spidermite problem that I usually just treat by hosing the plant, but lately I've been looking for other options. Yes please do a video on systemics. I'm particularly interested in systemics for spidermite and mealy bugs that are harmless to beneficial bugs, if any. Thanks for the great video! I've just found your channel and am liking it a lot 😁🌱

Ashley the go to Lady, I didn't see much when I'd had tried it. Cold press or nothing for my next try. Details are important! Thanks D.p. added 1 table spoon to my quart spray bottle will that protect my seedlings from the Fungus knats that killed 80 percent of my tomatoes last season. Thanks

This video reminded me how important your channel is; thanks.

Hi! I'm from Canada. I was able to get 100% cold pressed Neem oil from Amazon. No shipping issues, came right in! Also... LOVE this video by the way. Thank you for explaining the ineffectiveness of foliar feeding. I had no idea about this and have apparently wasted A LOT of time!!! hahaha cheers and happy planting

Thanks for answering my question on the product's effect on soil life, which is what I assumed it would be. Also, if we concentrate our effort on the pests and not the soil health, this will be a never-ending battle over "sick" plants won't it? Healthy plants = best deterrent for pests. Healthy soil = healthy plants. Also, whatever hurts pests gets into the soil and hurts the good guys trying to help us below. The other consideration for any pest deterrent would be its effect on pollinators.

Thank you for sharing this. Is Neem the organic solution for slugs? Can you share knowledge of organic methods to prevent slugs? I have an infestation and I don't want to use Sluggo because I read in research studies that sluggo affects birds and my garden plot is in a national park. Becuase my garden plot is in a national park, I cannot 'visit' my plot at night time to 'pick' off the slugs by hand - which I know is what most organic gardeners do. Thanks for any help you can give.

I would love to see a video on systemic pesticides. I've recently started growing hoyas and the hoya community seems to love systemics. However I'm not comfortable using them until I understand them better. For example I've read they can kill bees if they harvest pollen from the hoyas flowers. Although I keep my hoyas inside, if I moved somewhere warmer I might want to put them outside. But don't want to kill bees, sigh.

Absolutely STELLAR as always! I had considered spraying down the top foliage of my new plants with Neem Oil (after washing the top foliage off thoroughly outside) as a preventative treatment but many have said that iNeem can cause the leaves to be susceptible to burning. I can’t find anything definitive as to how long this potential susceptibility to burn could last. I am hoping to develop some kind of measures to prevent a new plant from potentially infesting my existing plants. I isolate them but am not sure for how long I should do so. I’ve only had Fungus Gnats and one plant with spider mites that I eradicated with isolation and Captain Jacks thus far. It’s difficult to decipher what to use that won’t destroy the soul micro biome…need more binge watching on your channel to find out 😜