How Much Neem Oil is Too Much

[EarlyBird]

Hi Folks,

Newbie here.

Having overcrowded my tiny community garden plot with six beautiful, thriving plants in a space which probably should only contain 3-4, I've had aphids and white flies.

I added some lady bugs, and while some have stuck around, they didn't seem to decimate the aphid population in the way I had hoped, so I went to the spray bottle of neem oil.

I am surprised that the branches which received the neem oil, though seemingly having culled many of the bugs, have also harmed the branches, making them withered and yellowed. So, I'm going to lay off the need spray.

But...is there is a matter of "too much neem oil"? And if so, how is it best used? Thanks.

[fonseca]

Did you spray it during the daytime? I always spray in the evening, or early enough in the morning that the plants will be dry before the sunlight gets intense. Never spray any kind of oil during the day.

I've never used more than 3 TBS per gallon, normally 2. The only plants I have ever burned include roselle and ice lettuce, never tomatoes.

[EarlyBird]

Thanks for the reply. Most of my spraying has been in the early morning. I wonder if the prepared spray is too concentrated, or if I've simply sprayed too aggressively. A garden mate of mine told me that the plants "breathe" through their foliage and I may have smothered the branches.

[zipcode]

For tomatoes 5% is about the limit. Depends on the age of the leaf as well. And actually depends on the variety also, I had one with unusual almost hairless leaves that was burned even at 3%.

[EarlyBird]

Good to know. I'm clearly over-doing it. Thank you.

[fonseca]

I have read that neem is the least clogging of all horticultural oils, but clogging the stomata could be an issue with regular spraying. I don't spray more than twice a week, and ideally I spray something else in-between, like compost tea.

Also if you are using a premixed neem product, what else is in there? Chemical solvents to keep it in a liquid state at cooler temperatures? You can get a quart of cold-pressed neem for around $20, a 1 gallon pump sprayer for $10, and natural dish soap for a few bucks. A quart of neem oil lasts me years.

[Gerardo]

Cold pressed neem is the way to go. Clarified hydrophobic extract from HD/Lowe's not equal

[zipcode]

Originally Posted by fonseca

I have read that neem is the least clogging of all horticultural oils, but clogging the stomata could be an issue with regular spraying. I don't spray more than twice a week, and ideally I spray something else in-between, like compost tea.

Also if you are using a premixed neem product, what else is in there? Chemical solvents to keep it in a liquid state at cooler temperatures? You can get a quart of cold-pressed neem for around $20, a 1 gallon pump sprayer for $10, and natural dish soap for a few bucks. A quart of neem oil lasts me years.

That's about the price here as well (europe). I thought it would be cheaper in usa. I find it expensive.
With 1 liter of neem you make 20l of solution. If you have mites and need to spray often and a decent amount of plants (I don't, I only have some), 20l is not that much.

[ginger2778]

Originally Posted by EarlyBird

Hi Folks,

Newbie here.

Having overcrowded my tiny community garden plot with six beautiful, thriving plants in a space which probably should only contain 3-4, I've had aphids and white flies.

I added some lady bugs, and while some have stuck around, they didn't seem to decimate the aphid population in the way I had hoped, so I went to the spray bottle of neem oil.

I am surprised that the branches which received the neem oil, though seemingly having culled many of the bugs, have also harmed the branches, making them withered and yellowed. So, I'm going to lay off the need spray.

But...is there is a matter of "too much neem oil"? And if so, how is it best used? Thanks.

Plain old soapy water spray will kill whiteflies and aphids easily, not much chance of a burn or a clog.

[gorbelly]

Originally Posted by EarlyBird

I added some lady bugs, and while some have stuck around, they didn't seem to decimate the aphid population in the way I had hoped

Lacewing eggs are a much better bet if you're looking for a biological option.

Or plant small, open flowers (herb flowers, alyssum, yarrow, etc.) near plants that get attacked, and the predators and parasitoids will come flocking.

[EarlyBird]

Thanks. I'm going to start planting those flowers ASAP.

[dono117]

has anyone mixed neem oil and daconil at the same time for tomatoes, peppers, etc.

[carolyn137]

Originally Posted by dono117

has anyone mixed neem oil and daconil at the same time for tomatoes, peppers, etc.

It's a definite NO, to mix anything with Daconil, ever.

I got tired of having to spray Daconil one week,next week spray liquid fertilizer, etc. but gave it a second thought as to mixing Daconil with anything.

So I looked at the Daconil bottle,the concentrate,not the premixed stuff, and saw where I could call if I had any questions. Both Ortho and Bonide distribute Daconil, I think it was the Ortho place I called, asked my question and luckily got connected with a man who was then head of their research unit.

And he told me that the dilution for Daconil, the concentrate,had been titrated to ensure complete coverage of the attachment sites on the upper leaf surface, so as to blocking them so that fungal foliage pathogens couldn't attach. Specifically the 2 most prevalent fungal foliage pathogens are Early Blight and Septoria Leaf Spot .And that if you added anything else the Daconil could bind to that,thus not enough molecules of chlorothalonil (Daconil) to be enough for good protection.

I learned my lesson.

Carolyn

[ginger2778]

Originally Posted by dono117

has anyone mixed neem oil and daconil at the same time for tomatoes, peppers, etc.

Yes. Don't do it. Major clogging and clumping, serious mess. If you do, you will be sorry.