Neem oil issues

[rainbowgardener]

In refurbishing my veggie gardens, I sprayed a lot of stuff with Neem oil, against bugs and fungus, including even spraying some quite healthy things preventatively.

I have never used Neem before, but here in wet, humid south I have lost a lot of things to fungal diseases, so I thought I'd try it, since it is frequently mentioned here.

Everywhere I sprayed the Neem, the leaves are badly burned and some are dying. Was I supposed to dilute it? Rinse it off? I feel very bad. I have always said I never spray anything but water. The first time I back down from that, turns out to be a disaster ....

[imafan26]

If you buy concentrated neem, the dilution is one tablespoon per gallon. It is an emulsion so you need to shake the container periodically so it does not separate out too much. Neem will clog sprayers so it is best to use it all up and thoroughly wash out the sprayer and especially the sprayer tip. Neem and other horticultural and botanical oils cannot be used when the heat approaches 90 or plants will burn. There are some plants that will burn with less heat and sulfur and neem cannot be used one month before or after application of the other, or the plants are almost guaranteed to burn. Since most of the pests I would use it on appear in summer, I don't use it much. It gives me a headache so I prefer to use ultrafine oil, milk, or sulfur instead for fungal prevention. Sulfur and the other oils have the same problem in the heat. Neem works well in cooler weather as a preventative but it is not effective as cure.

My friend likes to use neem for everything and it works for him.

Neem can be toxic to fish if it accumulates as it causes kidney failure in fish. Neem is an antifeedant and may cause bee larva that are fed neem contaminated pollen to fail to hatch. Neem should not be used when plants are blooming for that reason.

[applestar]

Oh bummer, rainbowgardener.
I’m sorry to hear that this happened.

Even with the best of intentions, things can go wrong. I think we’ve all had that happen at one time or another....

[imafan26]

Neem is a product that a lot of people like to use. It does need to be diluted. It can be mixed with an emulsifier to help keep it from separating out, but it should still be used in a few hours since it is not stable once mixed for a long time. It will turn orange and clog your sprayer if you keep it too long. It can be used as a preventive fungicide in cool weather and you know it is going to be raining for a few days. It is an antifeedant and it does require contact to smother pests.