I'm rather fond of impatiens -- they bloom like mad with the least bit of help (at least from my experience). Anyway, we got quite a bunch of young ones to plant in time for summer but two days later, they've developed white spots on their leaves. I thought they might be mildew but they don't look "powdery" at all. More like these white spots are eating the leaves and thinning them out from within the spots. The back of the white spots (back of leaves), they are brownish-purplish. Is anybody familiar with this? Because I planted them all over the place and now I'm afraid whatever this is will spread to our other plants and I am particularly fond of an apple tree in our backyard (if this does happen to be powdery mildew -- i hear it's quite contagious???). I wouldn't want that to get whatever this is!

Thanks in advance for any replies!

- bix