Well, I coundn't find anything on the net about using horticultural oil to deter thrips. There's a web site I didn't check though, Sacramento Rose ? something. I can't remember exactly what it was but it seems to me like they had a lot of stuff about diseases and pests on roses. I used it several years ago to identify some problems I was having with my roses when I was first starting out.

And like almost everything else you need to find out about these days, the answer is somewhere on the web. But on the off chance that you don't find anything about using oil for thrips, maybe you could test it out on your roses and then let us all know how successful you were.

As organic cures go, I know this group is usually gng ho for anything that's quick, easy, and organic. Cheryl

luv, see my post on this page about thrips on roses. I am a believer in beneficial nematodes now. I found the main source of the thrips (a new abutilon tree). I cut it down and bagged it in plastic. The roses were still infested. I ordered some beneficial nematodes from a company named hydro-gardens.com and sprayed them in at dusk. Even just a few days later there was a marked decline, and two weeks later I could not find any. Still none. I have a gardenia bush which is a thrip magnet and is presently blooming. Not one thrip on it. I can't believe it. I truly recommend it. As a disclaimer, I do trim the spent roses almost daily and bag them in plastic. However, I don't see any thrips on them.

I did spray with the horticultural oil and it did absolutely nothing except to make the foliage and little buds dry up and burn.I even waited for overcast days and still it did very bad things to my plants. I will order some of those nematode guys and try them out. Thanks for the info!
Molly

Thrips sure are discouraging. When I did a websearch last year, there was a site that said that they (thrips) didn't like soggy ground under the bushes, and that there is a three week life cycle, that must be dealt with. The site suggested a mulch of soggy (pre wet) newspapers, out past the dripline, and keep wetting it. Set it out, in the spring, which seems to be when bugs come out/activate to join their hosts. Someone had very good, but not perfect, success with this. Hmm, maybe there'll be fewer thrips in New England this year. For those with a long wet spring, please keep us posted.

Oh, heck, thats what I get for posting in the middle of the night. Thrips, I meant Midges. They came home in bagged root plants, from big box stores, hardware, discount, and job lot. I'm just not sure which problem came from which store. The root knot nematodes came from ocean state job lots, but that's no problem here as it was too cold and those bugs, all died. That root had a baseball sized dead growth.
One, and one only, of the nurseries, in Cheshire, had witchy growths, too. ick.