I have a Chinese Evergreen/Aglaonema Silver Queen, and a lot of the leaves are turning yellow. A few months ago, one or two of them were yellow and eventually fell off, but right now it has 7 yellow leaves and I had already taken 4 or 5 off last week... I thought it was getting too much sun in the afternoon so I moved it away from direct light in the afternoon, but leaves are still turning yellow. Anyone know why this is? The plant is about 5 years old, and I repotted it about a year and a half ago. Do you think it needs to be repotted again? Here's a photo. Thanks! Oh, and ignore the white flower you see on the left side. My Spider Plant is sneaking up on it. lol
I'd ordinarily suspect a watering problem (too wet, too dry, too dry and then too wet, too wet and then too dry), but since the only thing you seem to have changed is the light intensity, I'd guess it's probably reacting to that. (Which could also be, indirectly, a watering thing -- perhaps the soil is now drying out more slowly because the leaves aren't transpiring as much, or water isn't evaporating from the soil as quickly without the sun to heat it up? Are you finding that it's staying wetter longer than it used to?) They don't normally hang on to their leaves forever anyway. I mean, this doesn't necessarily mean anything at all, by itself.
Ok, thank you! No, there's been no change in watering, but I'll pay more attention to the soil to see if I need to water more or less often. Also, lately I see a LOT more sap on it. It's getting kind of leggy, so on the "stem", there have been a lot of beads of sap. Is that normal?
Could be insects (mealybugs, aphids, and scale will all leave droplets of honeydew behind, generally on the tops of the leaves). Guttation might also be to blame, though I'd expect that from the leaf tips, not from the stem. Aglaonemas that are blooming usually get sticky droplets on the outside of the spathe, which I suppose might transfer to the stems if the plant gets moved around a lot or something. Guttation is harmless (though it might indicate that the plant's too wet), and blooming is too, but you should check the plant carefully for bugs. Aphids actually look like bugs and are consequently pretty easy to spot; meaybugs look like white or light gray ovals, with or without tails, if they're singular, and like small cottony masses in the leaf axils and undersides if they're plural. There are lots of types of scale, but the one that I've seen most often on tropical plants is tan and oval, usually a bit translucent at the edges, and tends to favor stems, the undersides of leaves, and occasionally the midribs of leaves. If I've done it correctly, there should be a picture of scale and an image of mealybugs attached to this post. (I've never attached a photo before. ETA: Hey, I got it right.) Check for those before we continue. Might also want to get a picture of the droplets, if you can.
