I'm searching for the definitive guide to mixing pure neem oil. There has been a lot of discussion around things like water hardness, pH, temperature, emulsifier, etc. over the years, not all seems to be relevant to successfully mixing pure neem for application with an airblast sprayer. I'd love to hear from folks who have tried and failed and others who feel like they have it all figured out (and anyone else in between). This is an important topic as the season is just about to get started so anyone (and everyone) can avoid problems.

Here is the approach I have used more/less successfully over the years:

1. Warm pure neem to > 60F so it thaws thoroughly prior to any mixing activities.
2. Using a paint stirrer (on a drill for easier mixing), mix 1 oz pure neem + 0.5 teaspoons of organic dish soap or soap nuts (or other emulsifier) for every gallon of water you will be mixing into. E,g., i) 1% neem solution = 1 gal neem per 100 gallons of fresh water. ii) 1 gal neem = 128 fl oz. iii) Emulsifier needed = 128 x 0.5 teaspoons/ounce neem = 64 teaspoons = 10 ounces emulsifier. iv) A 2% solution would be twice these rates.
3. So, 1 gal neem + 10 oz emulsifier, mix thoroughly - add slowly to 100 gal fresh water in spray tank WITH agitation.
4. If the water is cold, use a little warm water (DO NOT USE HOT WATER - it can destroy the properties of the oils) to thoroughly emulsify the oil and then add the remaining water and agitate well. Make sure the oil is completely emulsified before spraying.
5. If there is oil floating on top add more soap or emulsifier as needed.
6. Spray as you would any prepared materials.

CAVEAT - If you have hard water, I would add something to soften the water (not salt) like Choice or an acidifier like citric acid. I know there has been some debate over the need to use a water softener and this is one of my primary reasons for this post. However, knowing what i know about how clingy hard water can be, it seems you'll get better mixing if you can reduce the hardness of your water below 75ppm, and even better lowering it below 50ppm for truly soft water.

I don't claim this is the definitive guide, though it is what's basically posted in Ahimsa Organics web site and that many of us have used in the past. I am very interested to learn (as would others, I'm sure) what successes and failures other have found in their experiences with Neem.
Thanks to Ahimsa Organics for some of the basic recipes and caveats embedded in this post.

Mike Biltonen, Know Your Roots
Zone 5b in New York

You forgot the dance. Growers absolutely must do the 'neem dance' while mixing to perfect the emulsification.

Pure humor to go with pure neem!. I love the idea of a consolidation post, Mike, to bring a range of complications and solutions to the fore.

My two suggestions would be:

-- Provide the math for a 0.5% concentration as that's the rate for general foliar application. This requires 1/2 gallon of seed oil per 100, to which I add an overflowing quarter cup (16 teaspoons) of biodegradable liquid dish soap.
-- Use two parts neem oil to one part karanja oil (70/30) for synergistic advantage, ease of mixing, and cost savings

Lost Nation Orchard
Zone 4b in New Hampshire

How about doing that in metric???
You are playing with ounces, gallons, teaspoons. And Michael even adds cups. Really, one has to be pretty good in maths to follow this.

Jolicoeur Orchard
Zone 4 in Quebec

Claude,
I trust your math. I've read your book. Besides those of us south of the border rejected the metric rationale a long time ago. we look our irrational ounces, Fahrenheits, and inches.

Mike Biltonen, Know Your Roots
Zone 5b in New York

So, after trying to more deeply understand mixing and using neem, and after a small-scale disaster, I have the following questions in a follow-up to my original post and Michael's neem dance suggestion: There aren’t any specific parameters available (that I am aware of) that talk about

i) optimal temperatures - Usha recommends something in the 105F range, but no hotter and certainly not luke warm. Thoughts? At what temp does neem breakdown, karanja?
ii) optimal pH - influences and is influenced by pH. 6.5? 6? More....
iii) optimal water hardness - 100, 75, 50 ppm?
iv) optimal emulsifier rates - this seems to be a bit sorted out, but I am sure depends on the other water characteristics and the eumulsifier
v) optimal (if any) rates of fish oil or karanja. Michael has answered the karanja question, but what about fish oil?

Any details or personal experiences people can provide are greatly appreciated.

Mike

Mike Biltonen, Know Your Roots
Zone 5b in New York

I second Claude's request for a metric dance, I mean, version of the mixture. I work in liters and kilos and all the many variations thereon and it drives me near crazy to hear (mostly former brewer types I think) talk of barrels as a unit of volume. I understand that is 31 gallons in modern parlance, about 117 liters, but because I age some of my cider in used wine barrels I always have to pause my discussion and brain when someone mentions barrels to think about the context--wine barrels come in different sizes depending on the alcohol inside--anywhere from 225 liters to 300 liters.

Beyond that, thanks for these ideas, in whatever formula you provide them--super useful.

Bitter Acres, Golden CO, Zone 6a (2018)
Golden Gate Canyon, CO, Zone 5b (2018)
XK Bar Ejido, Crawford, CO Zone 6a (homestead orchard)
Up A Tree, Lewis, CO, Zone 6a (2017)

We are having issues with neem emulsifying and have followed Michaels recipe. As for soap, I seem to recall it being mentioned in a video of Michaels somewhere that stated that Dr Bronners pure Castille soap isn’t as concentrated as say Seventh Generation. Can I ask members to comment on what soap they are using? I’m having to use an aweful lot of soap. The garden neem I have recommends 1tsp neem per litre to 1tsp castille soap. It is pure cold pressed raw neem.

On another note, is pure cold pressed raw neem oil sold as cosmetic grade good? I’m hoping to purchase a gallon of the oil that Michael uses but currently, my finances not in the best of shape. I’m also in western Canada so finding neem is a challenge. It’s almost $200 a gallon landed.

Thanks everyone!

Editor's Note: Check out Sourcing Pure Neem Oil in Canada for availability north of the border. Another thread entitled TerraNeem makes important distinctions about grades of neem. A new thread on using neem with low azadirachtin content (cosmetic grade) would be interesting.



Edited 1 time(s). Last edit at 07/01/2019 07:00AM by Michael Phillips.

I had a lot of trouble using hard cold well water. The neem would congeal and coat the inside of the spray equipment. It was difficult to remove. I have since connected a garden hose to a basement sink and use warm water that has been through the home water softener in the spray tank. It has made a world of difference.

I recall from an earlier discussion that at least some folks did not think there was any problem using softened water, though I was concerned about the salts. I have been doing this for two years with no observable harmful effects, and am a much happier camper at cleanup time, and also think I am getting most of the neem on the trees instead of lining my spray tank and hoses.

Turkey Creek Orchard
Solon, Iowa (zone 5A)

We found a solution! We changed from dr. Bronners to Seventh Generation (biodegradable). Amazing difference. Yes it's warmer out but the emulsification was so much better than cleaning was easier as was spraying. For 100L we used 1/2 cup. I tried sprays with 1/3 cup and less and it wasn't quite enough and adding more after the fact doesn't do the same as emulsifying early on.

Hopefully that's not too much soap. I've made lots of insecticidal soap that has much more soap but it's generally not a soil level.

Anyone chime in on this?