Any plant groups on the NO NEEM list?

I am going to use some neem solution as a preventive (fungis and critters) and wanted to know if any group of plants just hates it. I have a bit of this and that and don't want to cause undue harm to any of my greens....

the Euphorbias are pretty sensitive to just about anything, including neem...i'm talking about Euphorbia milli (crown of thorns) in particular. ferns and broms don't like much of anything either. Hibiscus will drop leaves whenever they are sprayed but it won't hurt them.

3js - I'm not sure I would agree with a 'one size fits all' assessment of all products we might refer to as 'neem'; or that we can attribute a plant's reaction to 'neem' unless we qualify what we're referring to as 'neem'. I've used pure, cold-pressed neem oil on E. milii AND several tropical Hibs, as well as well over 100 other species, and I've seen no ill effects at all on any of those plants when I follow a couple of simple guidelines. Often, people use products other than virgin oil - products that say 'neem' on the label, but what they're using is a concoction of other chemicals as the vehicle to deliver some form of neem that (because of some types of oil extraction processes) is largely lacking in the ingredient that makes it valuable to begin with - azadirachtin.

I would encourage you to try virgin neem oil, such as that which is available from Dyna-Gro. Test it on a part of the plant if you have concern, but my feeling is that you'll be pleased with the results as long as you aren't expecting an immediate significant knockdown. There is little in the way of immediate knockdown when you use neem, but it contains 1) powerful anti-feedants 2) anti-metabolites 3) chemo sterilizers.

This means that:
1) Adults and larvae alike will find plants treated with neem very bad tasting. Actually, it contains bio-compounds that disrupt the digestive cycle, but it's easier to remember that it makes plants taste bad.
2) Anti-metabolites do just as the term suggests. They disrupt metabolic processes. If you wanted an easy way to remember this effect, think: "It puts insects into a coma." They don't do much feeding or breeding in this state, so you can easily see the value.
3) As a chemo-sterilizer, it makes insects unable to reproduce. Think of it as an oral contraceptive in this case, or one that's absorbed through the skin.

Which brings up another interesting tidbit. It also renders larvae unable to form chitin and stops pupation.

If you have interest, I'll share how I use it.

Take care.

Al

Please do! :)

I bought crude, cold pressed, 100%, rank oil. I wondered what the label reads from the bottles aimed at horticulture. I planned to do a foliar and soil surface using say a teaspoon neem/couple drops safer insecticidal or murphy's oil soap per gallon of warm water? That is pretty weak but should get the word out that I don't want bugs eating my plants, lol. I haven't had trouble for a long time, but I got some new plants this year (Oooops) and have 2 small breakouts (whitefly on lantana and aphids on brugs). Spider mites are an ever present threat and I still see a couple fungus gnats, but they are dissipating...
I want to be careful if the spray could hurt a plant and it doesn't really even have a problem.

Who eats bromeliads? Well, except pineapple fruit.

1 spritzer bottle
1 pint hot water
1 pint (70%) rubbing alcohol (isopropyl)
1 tsp cold-pressed neem oil (I use Dyna-Gro)
a few drops dish soap or Murphy's Oil Soap (preferred)

Mix the hot water, neem, and soap in the bottle. Shake well. Add the alcohol. Spritz the plant. covering the plant entirely. Shake bottle very frequently while spritzing. Use all the mixture or discard it - it doesn't keep well. This mic can burn foliage in direct sun, so late evening applications are best.

I haven't found a plant that reacts poorly to 1 tsp neem in a quart of water + the soap, but a very few react to the alcohol. The alcohol simply adds immediate knockdown that the neem lacks, and can be omitted if you have any concerns. I would encourage you to include it and to just test it first on a part of the plant.

Al

I wrote this many years ago, before neem was hardly even heard of in the states. You might find it interesting:

Neem Extract as an Insecticide


In India mainly, but also Asia and Africa, grows a tree all plant enthusiasts should be aware of, Azadirachta indica, commonly known as the "neem" tree, and a relative of mahogany. Extracts from the tree’s seeds contain azadirachtin, a relatively safe and effective naturally occurring organic insecticide. Let me preface the comments following, by reminding you that the terms "naturally occurring and/or organic" do not universally mean safe. Pyrethrums, rotenone, and even the very dangerous nicotine are all organic insecticides that should be handled with great caution. Neem extracts, on the other hand are very safely used in a wide variety of cosmetics, as a topical treatment for minor wounds, as an insecticide in grain storage containers, bins, and bags, and a whole host of other applications. Neem is very safe for use around birds & mammals. I'll limit this discussion to its use as an insecticide.

Neem works in many ways. It is effective both in topical and a systemic applications. It is an anti-feedant, an oviposition deterrent (anti-egg laying), a growth inhibitor, a mating disrupter, and a chemosterilizer. Azadirachtin, a tetranortriterpenoid compound, closely mimics the hormone ecdysone, which is necessary for reproduction in insects. When present, it takes the place of the real hormone and thus disrupts not only the feeding process, but the metamorphic transition as well, disrupting molting. It interferes with the formation of chitin (insect "skin") and stops pupation in larvae, thus short-circuiting the insect life cycle. It also inhibits flight ability, helping stop insect spread geographically

Tests have shown that azadirachtin is effective in some cases at concentrations as low as 1 ppm, but some producers use alcohol in the extraction of neem oil from plant parts which causes the azadirachtin to be removed from the oil. Some products touting neem oil as an ingredient actually have no measurable amounts of azadiractin. I use what is referred to either as cold pressed or virgin neem oil. You may also occasionally find it referred to as "raw" neem or "crude" neem oil.

Neem oil is most often used in an aqueous (water) suspension as a foliar spray or soil drench. Commonly, it is diluted to about a .5 to 2% solution, but the suggested ratio for use in container plant culture is 1 tsp. per quart of warm water. A drop or two of dish soap (castile or olive oil soap is best) helps keep the oil emulsified. The mixture is then applied as a mist to all leaf and bark surfaces and as a soil drench to the tree's root system. It should not be applied as a foliar spray on hot days or in bright sun as leaf burn may occur. Remember to agitate the container frequently as you apply and do not mix anymore than you will use in one day. Neem breaks down rapidly in water and/ or sunlight.

Some users of insecticides feel the need to observe the instant results of their efforts in order to be convinced of the effectiveness of what they are using. The application of neem derivatives does not provide this immediate gratification. There is virtually no knockdown (instant death) factor associated with its use. Insects ingesting or contacting neem usually take about 3 - 14 days to die. Its greatest benefit; however, is in preventing the occurrence of future generations. It is also interesting to note that in studies it was found that when doses were given, purposefully insufficient to cause death or complete disruption of the metamorphic cycle, up to 30 surviving generations showed virtually no resistance/ immunity to normal lethal doses, so it appears that insects build no ‘resistance’ to azadiractin.

I have been using neem oil for five years as both a preventative and fixative and have had no insect problems on my container plants. Applications of cold-pressed neem oil are most effective for use on mites, whitefly, aphids, thrips, fungus gnats, caterpillars, beetles, mealy bugs, leaf miners, g-moth, and others. It seems to be fairly specific in attacking insects with piercing or rasping mouth parts. Since these are the pests that feed on plant tissues, they are our main target species. Unless beneficial like spiders, lady beetles, certain wasps, etc., come in direct contact with spray, it does little to diminish their numbers.

Neem oil does have an odor that might be described as similar to that of an old onion, so you may wish to test it first, if you intend to use it indoors. I've found the odor dissipates in a day or two. As always, read and follow label instructions carefully.

Neem oil can be purchased from many net or local sources. My favorite brand is Dyna-Gro, pure, cold-pressed neem oil. If you have trouble locating a source, you can contact me via the forum or directly.

Al

I was wondering if it harms worms or roly poly's (pill bugs, wood louse) or ants. I may keep the plants that are sensitive to everything seperate until I can do a test. I have euphorbias and orchids I would worry about and broms, tillandsias and ferns and cordylines, but I don't see any pests on them, so segregation until the spraying is done would be alright. So no problems with aroids/scheffs and their aerial roots?

What sold me on neem was being able to use it on figs without worrying about poisoning myself. Does anyone use neem on fruits trees and berries outdoors?

Thank you for the information about mixing it weakly being ineffective, at least that's how I understood it. For most of my plants, I just wanted a preventive for mites or any insect population that I still haven't noticed.

The alcohol version would make for quick evaporation. That can be cold to the foliage on a large scale, but like you said, instant knockdown.

Hmmm, you guys have given me alot to ponder.

i use it on figs with no adverse effects.

after reading all these great posts, let me clarify my previous post to say that my experience with neem is just that, my own personal experience.

the brand i use is Fertilome Triple Action Plus. it is 70% clarified, hydrophobic neem oil, 30% "other" and this brand is labeled for organic gardening, so i am assuming that the "other" is an inert ingredient. there are several plants listed on the label that may be injured in some way or another, but not killed.

"Does anyone use neem on fruits trees and berries outdoors?"

Neem is widely used in other countries & is a part of many cosmetics and medicines, including those taken orally. It is even mixed into bags of grain (rice) to help eliminate insect damage to foodstuffs. It continues to gain more widespread use in the US, even being applied to food crops to reduce pest populations via aerial applications (crop-dusting).

Since the alcohol is mixed with water, it markedly slows the evaporation rate, so I don't think that chill is much of a consideration.

Al

Tracks - you can bet there is an emulsifier carrying the neem oil in that product because neem doesn't mix with water. It is either a surfactant or a solvent and the very likely source of any problems you may have encountered. Usually, products like that have SOME of the benefits of neem oil, but are sorely lacking in the azadirachtin, which is the best part of neem oil. It gets destroyed during extraction via steam or solvents. I've tried other products labeled as containing neem, and have found them to be rather ineffective and to have unwanted effects on the foliage of some plants as well.

As I think I mentioned above, I've been using neem oil for more than 15 years, and haven't had any problems. That isn't to say it's not possible, because I sure don't claim to have one of everything, so haven't used it on any many of the plants you guys grow, but so far, all's well. I think it would be too bad if we took your bad experience with the product you're using as representative of everything 'neem' - like throwing the baby out with the bathwater. I hope you give it another look too, by trying the pure, cold-pressed oil next time you need it.

I find it very effective to treat the plants I over-winter indoors (the houseplants that summer outdoors) with neem 2 weeks before I bring them in, and again the day before I bring them in. I rarely have insect issues of any type indoors, and if I do, it's usually late in the winter & only a minor problem that is soon remedied when the plants go out.

Getting a little off topic here: I have to say that a huge part of IPM, in my opinion, is your/our ability to keep our plants healthy all year, including in the winter, which is not always an easy thing to do. I do understand plant physiology and have a pretty good grasp of what it takes to keep plants healthy, and I can say w/o the slightest hesitation that in the end, your soil (light levels, too) is the most important factor determining whether or not your plants will grow well and resist insects and disease within the set of cultural conditions you are able to provide.

Al

tapla, i didn't want to give the impression that i had a bad experience and wouldn't use it. i used it this morning in fact! the particular plants that i mentioned in my first post seem not to like much of anything "foreign" sprayed on them but it is usually contained to leaf drop or flower discoloration/drop.

i do love neem and have excellent results with the product that i use. i would love to try the cold-pressed neem and will check into it. however, finances will be a primary concern. the better the stuff, the more costly...but isn't that always the way? lol

edited to ask a question: tapla, the dyna-gro you are referring to, does it say Leaf Polish on the label? i'm trying to find the right one.

This message was edited Nov 6, 2009 9:49 AM

Al, I got the turface yesterday, I have sphagnum long fiber, I have perlite (supposed to be coarse, but it's mixed), what kind of tree did you use in your pretty soil mix? Anything else? I lost the thread about "Al's basic blend".... I have a variegated scheff rooted cutting that will be my first trial....

http://www.biconet.com/botanicals/dynagroneemoil.html

I am guessing that this is the product he means. I got some from someone selling essential oils and stuff. It was a little cheaper per 8 oz, and I am hoping it is the crude natural cold pressed 100% that is was declared to be...

i found it on amazon. 62.78 for 1/2 gallon concentrated and free shipping.

Good deal. I got my 8 oz for $9 shipped so yours was cheaper, but I never tried it so wanted a small one to start.

The product 3js linked to is exactly what I use. I don't think it says 'leaf polish' on it, though I know some people use it for that. I buy it 8 0z at a time, because a little goes a long way.

3js - are we talking about a discussion from another thread? See your Post #7247358 upthread. I'm confused. ;o)

Al

Yes, sorry. I will go find it. I was trying to gather ingredients so I can build a growing medium like your pretty one :).

Oh yeah - the pretty dirt ......

Al

Doesn't the neem have a shelf life? I heard keep it pretty cool, like the fridge, and still it has 1.5 to 2 year shelf life.

good question. i keep mine in the garage.

I keep it in the beer fridge in the basement ..... only pull it out and allow it to come up to room temp when I need it. The container I have now is over 5 years old & seems to work just fine - doesn't smell rancid, either.

Al

How long would it take a plant to exhibit stress from neem treatment if it was gonna?

just a guess, but i would say within a day or two you would see leaf problems IF you sprayed when the sun was out. otherwise, i guess it would depend on what kind of stress you were referring to but as tapla stated above, i doubt you will see much stress of any kind if it's properly applied. i will be using my liquid castile soap as my soapy agent.

mine arrived a couple of days ago so next week i will be trying the "good stuff"!
thanks to tapla!

a question for tapla...have you found it to be of value in lessoning weevil damage at all? my gardens suffer tremendously from the Little Leaf-Notcher Weevil. the notches i don't mind but it is a root weevil and destroys plant roots with a vengeance. in addition, it chews the soft new tissue of certain plants, particularly roses.

i have tried so many organic products the past two years and have gone back to the neem now.

It's supposed to be effective on weevils, and remember it's a powerful anti-feedant, but I've seen a grand total of 1 weevil here, so ........ wait - that must mean it IS working. ;o)

Al

thank you.

it is so weird. we've been here 5 years and the first 2 i used neem all the time. the third year i started seeing weevils (hundreds of them) and assumed the neem wasn't working so i switched to many other things. i was at the end of my rope when i started trying to remember what was different the first 2 years. well, it was the neem and i didn't give it a chance the third year.

i am really praying that this is the answer. thanks again for turning me on to the good stuff. i just didn't realize there was that much difference.

Thank you.... I sprayed Mon night using 1 tsp per quart warm water and several drops Murphy's. I sprayed orchids, broms, aroids, gingers, lantana's, cordylines, begonias, coleus, gesneriads, cissus, ficus, scheffs, dracaenas, euphorbia (pencil one, and the devils backbone), aloe, geraniums and hibiscus, I don't see anything too bad. Leaf drop on the pencil succulent, ready to open phalaenopsis buds dropped, and maybe rabbits foot fern didn't like it. Nothing serious. Those things may have been caused by my teenager building a roaring fire and having it around 90 in there the night before. I used Murphy's Oil Soap as the sticker/surfactant. The smell was tolerable and I found a couple infestations since spraying, so I must have made them unhappy :).

How often should I spray until I have all the problems resolved, and then probably monthly as a preventative measure?

I found some scale on a fig and scheff. I went over them by hand yesterday and then applied Murphy's, alcohol and warm water since I had just sprayed neem. That is the primary worry so I don't have to rub every inch of leaf, petiole, stem, and trunk again :).... Oh, and I found some mealy bugs. I haven't seen mealy bugs for 20 years, but I found some on a flax plant, very well hidden.... They are on my hit list next :)...