Spraying Neem on Apples in Hot Weather

Is there a danger in spraying Neem oil for aphids when the outside temperature is 80 degrees and above? If I spray early morning say in 70’s, the oil will still be on the leaves later in the day when it’s 20 degrees hotter.

I tried Tanglefoot- on two trees it eliminated aphids and two others it had no effect on aphids. Am now armed with Neem. Thanks in advance for advice.

Neem works well for aphids but on my trees I notice some leaf damage as the temps got hotter. I’m now using soap water and rinsing it all off in 30 minutes. The high temps do seem to be the culprit even with soap. Good luck, Bill

I’ve sprayed neem mixed with liquid fish in similar conditions – 70 degree morning going up to 90 in the afternoon – without any damage. I used 1.5 tablespoons neem, 2 tablespoons liquid fish and a little bit of dish soap in a 1 gallon sprayer. Smelled pretty bad working in the orchard for the rest of the day.

Does Neem oil need a surfacdtant/spreader like dish soap? Is “a little bit of dish soap” roughly say one tablespoon per gallon?

It depends on what kind of neem you have. For raw neem you need to add some dish soap or it will clog your sprayer. If you are using a commercial neem spray those you can usually just spray on without additive; check the label.


About a tablespoon, yes.

Great question hambone. For me it never dips below 85F in the summer so not an issue—I cannot use neem then.

I have read others say they did not have an issue if applied early in cooler morning such as above, and when the afternoon subsequently heated up. I have read others say it does hurt the plant.

I guess that leaves you with making a small batch and giving it a test. Let us know the results if you do.

I opted to spray Dawn detergent last night near dusk at two tablespoons per gallon and then I washed it off after about ten minutes to prevent any burn issue. Appears to have killed the aphids. Can’t figure why my Tanglefoot rings aren’t working to stop aphids.

Do aphids crawl up a trunk or fly in?

For me with just a few trees this works well. The soap and rinse might get too labor intensive if I had more trees to deal with. Bill

FWIW…I grew tobacco here many years ago ( long ago Maryland was a big tobacco state) and it grew huge and beautiful. The only problem I had was aphids…and it was a very, very bad problem. I remember searching and studying up on the problem and supposedly Lemon Joy worked the best for them. I forget why, but I think the lemon component had an additional helpful function. I also remember reading you should not use Dawn because the grease cutting ingredients are problematic in some way, again and unfortunately I don’t recall why.

I do know the lemon Joy did work, but it formed a soapy slime full of dead aphids. Not a problem for fruit trees at all, but a real pia if you are harvesting the leaf as in the case of tobacco.