This photo–except for the dated bathroom tile–is actually much prettier than what it really it. All the plants in the tub have just been sprayed with insecticidal soap–my remedy of last resort, really–because I have discovered a quite extensive spider mite infestation.
You can’t quite tell, but there are 6 plants here in the tub. And they only look so good because they are still glossy from being sprayed.
This is the window where they reside. That big croton in the photo is in the tub–it’s pretty badly infested. It’s an old plant–I am guessing about 8 years old or so.
The big hibiscus next to it seems okay so far. We’ll see.
And the lemon on the end is probably infested but it’s too big to move. It’s going to have to hang on until I can get it outside.
It’s that point in the season where the insects are really getting into high gear and I am counting weeks until I can bring the plants out. But at least it’s just weeks now and not multiple months.
Gardendaze 
Have you tried nematodes? I have been looking for some for my houseplants (I have tiny black flies in the soil) and there appears to be something for every problem infestation. And I am ordering mine on amazon!
Mite infestations have potential to be worse among the houseplants because the insects that should control such infestations do not proliferate within the home. It is easier if they can go outside for part of the year. It may not eliminate the mite infestation, but it controls it.
Oh yes, once I get them outside–which might occur at least temporarily this week–I can hose them off regularly. That will at least get the undersides of the leaves more easily and disrupt the mite breeding, which is the important thing. Normally washing off is my usual remedy anyway but I thought it might be too unwieldy with these larger plants, even in a bathtub