Neem Oil application damaged my Michelia Alba new growth

yellowthumb(5a Ontario)August 12, 2009

Hi,

I have been reading many good things about Neem oil. So I made a mix of 10ml neem, 1 liter of water and 3 ml of Dawn's dish soap. I applied this mix to all my plants very late in the evening to avoid any sun damage.

After two days, all other plants are fine, except my Michelia Alba and Magnolia champaca. The new growth on the Michelia Alba are mildly damaged. It's having morning and afternoon sun after 3pm. There are brown to black spots on the back side of the leaves. It's hard to see from the upside of the leaves. Not all new growth were damaged. Some not at all. So the damage is not even. The Magnolia Champaca took the hardest hit, maybe because it's located in the full sun. The small leaves are kind of distorted and brown/black on all edges. All small leaves were damaged.

I got my neem oil from a local garden center sold as a leaf shine. Our weather is kind of warm and humid those days.

I just finished reading a good post by Al on the house plant forum.

Is there anything wrong with my neem application?

YT

Thank you for reporting this comment. Undo
kevin_mcl(S Ireland)

I suspect your mixture was a bit on the strong side.
I saw similar symptoms once when I used far too much dish soap as a sticker in a one gallon sprayer for roses. Usual recommendations for using dish soap is a half to 1 teaspoon per gallon - or a couple of drops in a liter. I have also read some good things about neem oil but it also likely - that to avoid being fried, oils of any kind should be used very sparingly on plants subjected to full sun.

    Bookmark   August 12, 2009 at 5:59AM
Thank you for reporting this comment. Undo
meyermike_1micha(5)

Be care yellowthumb!

I think there is a warning on the bottle for certain plants that are not that tolerant of certain oils, along with many hairy and thin leaf plants such as violets, and succulants.

Do a test spot on a leaf that you will not miss if it should fall off.

I always mix neem a bit weaker in strength than the instructions call for, and it still does a great job. I too have lost a many leaves and buds, especially on my citrus do to the mix being to strong.

Did you know,that even too much dish soap can burn certain plants too.. Fyi, there is a residue left behind if too much is applied. I usually wait a couple of hours for the neem to work, and then give all my plants a good rinse of warm water. This way I have not lost a single leaf or bud from neem anymore. I can't tell you how many gardenia buds I have saved by rinsing after spraying, all the while giving the neem a chance to kill the mites attacking them. And how many I lost just leaving the neem on without a good rinse. It works...

I hope you are well and your summer is still going strong..;-)

    Bookmark   August 12, 2009 at 2:07PM
Thank you for reporting this comment. Undo
tapla (mid-MI z5b-6a)

My post suggests that you only use cold-pressed neem oil. I'm guessing your product was not, and it was the vehicle that did the damage. I've never had anything damaged when I apply as you described, using the cold-pressed product.

Al

    Bookmark   August 12, 2009 at 5:15PM
Thank you for reporting this comment. Undo
yellowthumb(5a Ontario)

Thanks everybody.

It maybe too strong on the soap side. Given the soap is super concentrated. After mixing, I can see there are lots of foams. Guess too much soap.

Is it a good idea to rinse after applying neem? I thought it's the neem that deters the insects as a anti-feeding agent. If you washed it off, it may not be as effective.

I asked the dealer about the neem oil being cold pressed or not. No answer. I guess not. Cold pressed is much more pricey to produce than steamed.
I just ordered the dyna-gro neem oil and Dr Brooner's organic peppermint pure castile soap. This is the soap that recommended by many others.

Here is the instruction from dyna-gro site.

"Mix 1 1/2 teaspoons of neem oil per quart of water (1 oz per gallon) to make a spray mix. Add
about 1/3 teaspoon (1 1/3 tsp per gallon) Dyna-Gro Pro-TeKt, liquid dish soap or other surfactant
to get the oil to emulsify in water."

I am going to try 5ml of neem, 1 ml of dish soap (or till the foam starts to form) and a quart of water.
I am wondering anybody used the pro-tekt as the surfactant.

Thanks everybody
YT

    Bookmark   August 12, 2009 at 6:47PM
Thank you for reporting this comment. Undo
lathyrus_odoratus(5A-IL)

I would suspect that Dawn was part of the problem. It's a detergent, not a soap. It will strip the plant's protective surfaces right off. Other people who have used it have defoliated entire plants.

For a soap, use Murphy's or maybe Ivory. Don't use any detergents. Or, try using one of the saponin based items like EarthJust Assist or Coco-wet.

    Bookmark   August 12, 2009 at 6:55PM
Thank you for reporting this comment. Undo
yellowthumb(5a Ontario)

Thanks.

I thought Dawn was a soap. I guess it's pretty hard now to get any real dish soap from any grocery store anymore.

I have the coco-wet, are you sure it can be used as a sufactant?

    Bookmark   August 12, 2009 at 8:30PM
Thank you for reporting this comment. Undo
yellowthumb(5a Ontario)

I just did a research on coco-wet, yes, it's a all natural surfactant from spray-n-grow. I guess this should be safer to use on plants than soap based surfactants. I already have a small bottle on hand, this is perfect.

    Bookmark   August 12, 2009 at 9:10PM
Thank you for reporting this comment. Undo
yellowthumb(5a Ontario)

I just got a quart of dyna-gro neem oil, even enough to cook for a family of two. I am wondering what's the shelf life of neem oil. Dyna-gro recommends putting into room temperature to prevent solidification. But others recommend putting into a refrigerator. How you guys store it?

    Bookmark   August 12, 2009 at 9:44PM
Thank you for reporting this comment. Undo
tapla (mid-MI z5b-6a)

Fridge until I need it. Then zap it. Then back in the fridge 'til I need it again.

Al

    Bookmark   August 12, 2009 at 10:01PM
Thank you for reporting this comment. Undo
lathyrus_odoratus(5A-IL)

Oh, I never thought about that, but oils do get rancid relatively quickly. I'll move mine to the fridge....hubby will love that! I have mix components all over the dining room, plants starting in the hallway, African Violet leaves rooting in plastic bags on the fireplace mantel and now Neem in the fridge. Sure, this is how everyone lives, isn't it?

    Bookmark   August 14, 2009 at 12:48AM
Thank you for reporting this comment. Undo
rhizo_1 (North AL) zone 7

I have insect specimens in our freezer. :-O

    Bookmark   August 14, 2009 at 1:02PM
Thank you for reporting this comment. Undo
justaguy2(5)

I have insect specimens in our freezer.

You are such a nerd ;)

    Bookmark   August 14, 2009 at 1:08PM
Thank you for reporting this comment. Undo
justaguy2(5)

Oh, I never thought about that, but oils do get rancid relatively quickly.

While this is purely anecdotal, I have a quart of Dyna Grow Neem Oil on my shelf that is 3 years old and is still fine. I just went and gave it the smell test ;)

    Bookmark   August 14, 2009 at 1:15PM
Thank you for reporting this comment. Undo
meyermike_1micha(5)

Me too.....

The same thing! Dyna Grow Neem Oil...
Thank God it is still good. Since I picked that stuff up, the price of a smaller bottle now cost 2x more the the oringinal big bottle I have..Sheesh

The smell test past for me too.:-)..

    Bookmark   August 14, 2009 at 3:15PM
Thank you for reporting this comment. Undo
lathyrus_odoratus(5A-IL)

Hmmmm - maybe the type of oil it is prevents it from getting rancid. Even better. No need to stress hubby over this....I'm sure I'll stress him over something else instead :-)

    Bookmark   August 14, 2009 at 11:52PM
Thank you for reporting this comment. Undo
yellowthumb(5a Ontario)

It's probably a good idea to put it in a fridge. Just to keep all the active ingredients as effective as possible.

    Bookmark   August 15, 2009 at 12:28AM
Sign Up to comment
More Discussions
Question about too much dryness in my container garden
I have several Behlen food-grade stocktanks (1x2x6)...
catherinet
PVC liner OK for growing food?
A contractor friend of mine made me a planter box to...
gourdo1
Pine Bark Fines Substitute?
I'm having trouble finding pine bark fines for the...
johnweh
Help! My slash pine seedlings in containers are turning yellowish
I have several hundred slash pine seedlings I put in...
Florida Native
Aglaonema - help
I bought this red aglaonema couple of months back....
bluehaven_gweb
© 2015 Houzz Inc. Houzz® The new way to design your home™