Treating scale on large, very-leafy plants?

What is your suggestion to get rid of scale on my peace lily.


I have used Neem Oil, diluted with water and that killed my Boston fern, the Pothos reacted well but that was for Mealy bugs.
I have used rubbing alcohol diluted with water, the palms reacted badly. All of this info came from others who claim to have used these treatments.

I do not want to kill them before the bugs do it. I have a peace lily in my bedroom, 6' tall, 7' in diameter, afraid to put in on the terrace outside. Another smaller Peace Lily I have was looking like it needed a pick me up so Iput it outside and it got scale in 1 week.

Hi Larry to ATP.

I have used insecticidal soap to kill scale, but it can take repeated treatments. You can also find systemic treatments. (check the UC Davis link)

Here is some info on Spathiphyllums and scale. I hope this helps.

http://en.allexperts.com/q/Hou...

http://homeguides.sfgate.com/p...

http://www.ipm.ucdavis.edu/PMG...

edited to fix link)

Larry, if you don't have a lot of plants, just removing the scales by hand works for me. Then spray with a soapy remedy of some kind.

Scales are protected by their little 'shells' from a lot of the soapy insecticides, but the nymphs (young 'uns) don't have shells yet so they can be killed by insecticidal soap. You may need to repeat the soap application a few times to take care of new hatchlings.

On a larger scale (no pun intended ) a horticultural oil spray is recommended, as it will virtually smother both the adult scales with shells and the nymphs. But don't let your plant be in the sun if it has an oil spray on the leaves, or the leaves can burn. Keep it in the shade until you wash the oil off (wait a few days for it to work, of course). If you wash it off with a soapy spray that will again reinforce the treatment, to kill off newly hatched bugs.

I have completely given up on using any systemic insecticides, as it seems the bugs get resistant to them very quickly. Just like antibiotics, we've over-used them to the point that they are nearly useless now. It just takes a few bugs to survive the initial application, and when they breed, the resistance is passed on to all the new generation bugs. Some bugs' generations are counted in weeks!

Gee Larry, I lived in zone 10 Florida (Jupiter area) & used straight alcohol on my pygmy date palm to get rid of scale & it never missed a beat. I have often used straight alcohol on many plants & never had any problems with anything reacting badly. In fact, I have a friend down there who just used alcohol in a spray bottle on ferns to get rid of mealy bugs & the ferns were fine.

Hey, that sounds like a great use for some of that bottle of cheap vodka that's been in our cupboard forever . . .

I should have said straight rubbing alcohol. I suppose the *other* kind would work too.

Seriously now, alcohol works for the scales with the little shells too? I've used it for mealybugs, but not for scale.

Maybe they get drunk and fall off . . ??

I rub it on with a soaked paper towel & most of them just come off in the process. Sometimes, I will have to scrape a few with my fingernail. I wet the paper towel down good too & then just run it all over the leaves to get any of the "crawlies" while I'm at it.

I am a big fan of rubbing alcohol! The only time I've ever had a negative response to it was on either tomato or dahlia seedlings (I forget which now) that were sitting near the rear window in my greenhouse when I went after some wasps in that window with my trusty spray bottle of alcohol. They got a bit of overspray from my enthusiastic attack and some of the leaf tips got a bit brown; but I think that was more from the combination of sun plus alcohol, rather than the alcohol alone.