Don't be fooled into making a positive association between something like cinnamon and thrips. I dont mean that as a criticism, but I have had a thrips problem for about 3 months now and in spite of me doing very little to try to stop it, the numbers remain very low and sporadic. If I'd done something like spray the plants or hang up yellow cards, I would have easily assumed it has kept them under control, yet in reality, it would have been a false assumption, because so far they haven't really exploded beyond finding the odd one here and there.
..If you get what I mean.
Oh, btw, thrips controls:
- ladybirds and their larvae <-this definitely works to some extent I think, I had some ladybirds appear and they must have been eating something.
- Amblyseieus cucumeris (forgive my spelling!) <- should work, its the commercial solution
- sand (possibly)
- reflective mulch (possibly)
- picking them off by hand <- this is all I've actively done so far
- using the weird vacuum cleaner contraption I invented on another post <- havent had enough thrips to test it fully yet but it should work on adults!
- the cold <- by this I mean nearly freezing temps
- almond/vanilla essence on a sticky blue or yellow card <- this did absolutely nothing for me at least, other than catching a ladybird. doh.
last resort
- soap based spray <- won't kill the ones in the soil.
HTH
oh, p.s. just noticed you ordered pirate bugs, should do the trick although I think they bite people so I'd watch out for that? Keep the greenhouse temp up too...the reason I couldn't use them yet is because they need >16C to be effective.