Only the Good Lord will know for sure exactly what caused your problems, but the fact that your problems are isolated to a limited number of plants all in the same location, should tell you something.

I have reviewed your link re: the use of Neem Oil as a preventative.

I personally do not believe it is an effective way to prevent pest infestations anymore than chanting for rain will produce rain. I think any product that will PREVENT pests, will likely do more harm to the plant or the people who consume the fruits of these plants.

Neem Oil is great and organic and natural and all that, but we're not talking about peppers and squash and hardy food bearing plants. We're talking special herbs here that are far more sensitive and finicky.

Neem Oil is hard on full grown plants as well as young tenderlings and as with anything, you only give these kinds of plants something when they need it.

Timing is everything with these flowers you are growing and there is no benefit really to giving these plants anything they DONT NEED.

This is where most people fuck up their shit. They give their plants unneeded stuff.

Try and avoid this type of mistake at all times.

If you sprayed the neem as directed, and you thoroughly covered the undersides of the leaves, odds are certain you got some stem drainage running down.

Use neem oil ONLY if you have SPIDER MITES. It should be a LAST RESORT item on your list of pest control but certainly NOT as a preventative, in my opinion.

Johnson & Johnson's Baby Shampoo and water is the best in my book. Or, anything else that contain essential fatty acids from soap.

The author of your article also refers to neem oil as being "systemic", meaning if watered into the soil, it will enter the plant and travel that way...yet, immediately advises you drench the shit outta the leaves.

HUH?

Again, neem oil is ok if emergency situation of pest infestation dictates it, but only then.

And with these plants, its that way with everything.

P.S. There are many masters who grow and clone and make all kinds of wonderful fragrant flowers with rock wool. EVERYTIME.

Good luck.