So let's start by asking a question - where did the scale come from in the beginning? From the environment...from the air, from outdoors, "out of the everywhere into the here." Meaning, the bugs are already around you. You did well to control them on your houseplants, now don't worry so much. If you want to put the plants outside, go right ahead. There are predators out there that control them most of the time. The reason you saw ants in your plants (oh gosh, I said a funny) is that the ants were feeding on the honeydew excreted by the scale, much like aphids, aphids and scale being in the same order of insects.

Yes, you should discard the potting medium the infested plants were in, because of the possible presence of eggs. Also the pots that you used should be thoroughly washed and disinfected with a dilute solution of bleach. You should do this with old pots before putting in new plants anyway.

How about telling us what kind of plants you're talking about...and the type of scale, if possible.

They are citrus plants and were just under the patio so i guess the scale just came from somewhere outside. It wasnt on the plants when i got them 2 years ago. So if i plant them in the garden should i continue spraying them because of the scale or leave them alone? I will definitely discard the potting mix and wash those pots though.

I would keep an eye on them, keep checking for insects, as you should with all your plants, and spray them only if you see bugs actually coming back.

great...thanks theficuswrangler ill keep checking them and plant them in the garden :) .............with the ants...i think they live under the pavers on the patio...i am worried if i put different plants there they will come back and bring the scale with them? how do i stop that from happening? as i do want to put other plants there :S

Ants. Oh lord I hate ants. I've been battling ants in my house all winter, got them out of the kitchen, and they came back 10 times worse in the bathroom. I generally don't worry much about ants in my potted plants, I suppose there are a few but it's no problem. If you want to keep them out of your patio plants, there are probably several things you can try - Maybe some other folks can offer suggestions. Maybe you could start another thread asking just for advice in thwarting ants.

YES!! i have been battling them since we moved into this house...thank god we are renting and didnt buy it! They come in just after the big rains and we just cant get rid of them. I will do some research and then perhaps make a thread asking people. Thanks for your help :)

You won't get rid of ants outside, more will just move in from the neighbourhood. The main thing is to keep an eye on the plants and deal with scale as soon as it shows up. Because it's the wet season ants are on the move upwards, they will seek out higher sheltered spots, pots on a patio or verandah are idea homes. You can use Amdro, sold in Bunnings, Elders, or Landmark, etc., but it is expensive, although very effective. Some ants don't touch it, like Green Ants.

The thing you'll have to watch outdoors with citrus is leaf miners. They tunnel in under the skin of the leaf. If you see distorted/deformed leaves that's probably it.

Hmmm i will keep an eye out for leaf miners then too...thanks :)

Amdro is not labeled for use near food plants.