Elimination of Scale?
 

When I moved my orchids (~40 plants) outside this summer, I noticed that a scale problem that I thought I had dealt with had spread to several plants. Before I move into a new greenhouse this fall, is there any way to completely eliminate it or should I start over with all new plants?

If you can use a systemic pesticide like orthene or something with MERIT in its ingredients panel, this will completely wipe out all sucking and chewing insects from your plants, be sure that you can give them the humidity they need to fight off mites though, these pesticides do not kill mites, for those either keep up the humidity or use a miticide.