Hi Jane, That's too bad about your special plant. Here's hoping it recovers. A few years ago, I bought Bonide insecticidal soap to use in the house. Active ingredient was potassium salts of fatty acids. "Ideal for organic gardeners." Milder than what you're talking about. For 3 years now, my plants have been sprayed with Safer's 3-in-1 product - fungicide, insecticide, and miticide, suitable for organic growing. Works for me. Just yesterday, I ordered the 32-oz. concentrate. I use it in the bathroom with the critters shut out. My super-duper awesome ammo, though is 1600 X-Clude. Main ingredient is microencapsulated natural pyrethrum, from chrysanthemums. This year will be the 4th that I've used it. The label says you can use it inside, but a commercial grower who uses it advised against that. The aroma is strong, and I wouldn't use it in the house, even if there weren't critters around. Well, if I could aim fans out the window, close the door, and shove towels underneath. In late summer/early fall, about when you'd be bringing plants inside that have been outside all summer, you spray plants five days apart, 2 sprayings total. Online prices vary wildly, if you decide to check it out. If you go with it, let me know, cuz there are some specific instructions for it to be the most effective. http://www.ghorganics.com/XClude1600.html Here is a link that might be useful: Safer 3-in-1 plant spray

I've owned a Persian lime for about 12+ yrs. Scale has been an annual problem after spending summer outdoors. In the past I've used insecticidal soaps, Ultra Fine all season oil, Organocide, alcohol & Q-tips with limited success (more like a slowdown if anything at all) A couple of years ago, a local nursery shared a little known bug killer: SIMPLE GREEN diluted in a spray bottle 30 parts water to 1 part Simple Green which is the dilution rate listed on the label. (Be sure to use the original Simple Green, they've come out with lots of new formulas in crazy colors). With the plant outdoors or in the shower, spray to the point of runoff on the entire plant. Scale this year is especially bad and I tried Pyola at the suggestion of a friend (it contains both pyrethrins and oils) and that hasn't worked at all. The first time I tried Simple Green, every scale I examined had been killed. I sprayed again 2 weeks later to catch any missed or newly hatched. I did not have scale again until it went outdoors the following summer. IMO Simple Green is a heck of alot safer than malathion and systemics which for me would make the fruit inedible. Amccour, do you get fruit from your Key Lime in zone 5? I never had much luck with getting key limes to harvest; I always thought that I just didn't get enough hours of sunlight early enough to keep any fruit on the tree. I gave it up with the scale before I knew about Simple Green.

Drench the foliage with a mixture of 1 cup of garlic juice, 1 cup of liquid soap in 2 gallons of water. Repeat 3x, one week apart.

The only way to eliminate scale is to treat for it - there is no natural control or predatory insect that will completely address the issue (although they can help). And the recommended method is with a horticultural oil applied at the appropriate timing of the life cycle of the scale organisms. Ants can be more easily deterred if you wrap the trunk in a sticky tape or something like Tanglefoot to keep them from climbing the tree. They are just after the honeydew or the sweet, sticky substance the scale excrete - if you control the scale you will also be controlling the ants.