After bringing plant home, it was happy and growing. I then noticed some of it's newer leaves starting to turn yellow and die. After close examination, I noticed something happening under the leaves (white in color? .. I didn't think it was mites). Since I wasn't sure what it was, I washed the leaves in soapy water instead of using an insecticide. I haven't seen any sign of the underside looking like before, but the leaves seem to be losing their rich color and I don't want it to die! It is still in the original dirt, which seems to be more moss than soil. Should I just replant it? Could I be over watering it?
It gets good light, not sun.

Thank you much!

Welcome How about a picture of your plant? How long have you had it? Are you growing it outside or indoors? They like lots of water, so I doubt you could be overwatering. I have mine in just regular potting soil, so you might consider re-potting.

If outside, it's probably going dormant, as the nights have been really too cool for most Alocasias, I think. (you are only about 20 miles north of me) Nothing to worry about, it will jump up again once it's warm. Definitely bring it indoors or protect it for the next two nights that are supposed to dip into the 40's!

If indoors, again I think you might want to re-pot into good potting soil. If you plan to move it outdoors for the summer (they love it!) put it in a fairly big pot and wait until the nights are above 60deg. They are heavy feeders, so if you haven't given it any fertilizer, that's what it needs! Don't forget the fresh potting soil might have fert already added so check what the package says. IF it says something like "feeds plants for 3 months" then you can also give your plant a drink of soluble fert, something like Miracle Gro to green it up again, and give it a boost. After that, only give it soluble fert if it starts looking pale again. After the 3 months (or less . . . in warm wet weather) fertilize with a good balanced time-release product.

The white on the backs of the leaves was probably some sort of insect infestation, scale or spiraling whitefly. The soapy water treatment you used was just the ticket! Keep an eye on it, though as they might come back. Just wiping with a sponge with soapy water will usually keep it under control.

ash898: Can you upload a photo so that we can see the plant? Yellowing leaves can mean too much water; does the container have drainage holes in the bottom? If it's growing in Sphagnum Moss only with improper drainage, the moss could be staying too wet. The white stuff on the undersides of the leaves could be mealybugs and soapy water should take care of them but might not get any remaining eggs that haven't yet hatched. I use Isopropyl Alcohol for mealies which works really well and if there aren't many of them you can q-tips, dip them in the alcohol and wipe the mealy bugs. I'd recommend removing the plant from it's pot and completely rinse all moss or soil from the roots and re-pot in a well draining potting medium.

I agree with dyzzypyxxy, Alocasia's go dormant when the temp's are cool. I'm on the east coast of Florida, way NE of your area and my one or two Alocasia are dormant now but will pop up again when we have continuous warmth. I've never fertilized mine, maybe Elaine can share what type of fertilizer should be used for these beauties.

Oh, and by the way Welcome to ATP, you'll love it here!