well, soil retains water - so if you create a mix that contains soil (I think of that as the soil backing/or base) - then the other components ... the perlite, or bark, or rocks - well that's the extras. :) ... Now if you have a mix without soil - then peat would be the component to 'hold' the water... but if you have soil in there. Doesn't it do it already? why add peat too? I mean, you're talking in a pot - you water it often enough that if you're looking for the absorbtion component in peat - soil kinda' does that. - most often you don't want to much water retention in a pot. - now if you were saying mixing the peat in your garden bed - then I'd be a bit more understanding. Can't stand hosing the yard any more than necessary. I'm NOT an expert. REALLY. And I constantly show where my knowledge is lacking. I try to make sense of these mixes and goodness knows - I'm glad for folks like AL who can reason out how all the stuff works ... cause my mind can only wrap around so much info at once - and then I need my buddies to lead me through it when it gets to complicated. Thank goodness for GW and the good friends I've made here. :)

Unless Emily has confirmed there are actually 2 separate plants and not 2 branches masquerading as trunks, which are connected below the soil line, we probably shouldn't take for granted there are 2 plants. Even if there were 2 plants, it doesn't look at all like there would be the kind of competition between plants of the same species such that one would be genetically vigorous enough to hog resources to the point it would create deficiencies sufficient to manifest a steep decline in the other. I mean, there are no roots crawling over the surface of the soil, and there is no disparity in size that could suggest a larger, taller plant might be shading out its shorter, smaller counterpart - so what competition? It's not unusual for one or 2 roots to be negatively affected by disease while other roots in the same pot or even on the same plant are better able to cope with less than ideal soil conditions. The result is often the death or decline of 1 plant in a group planting or one branch on a tree. Roots do have very specific connections to individual branches such that the death of a root can almost automatically mean the death of one branch. The 1 root to 1 branch connection is so strong in Thuja occidentalis (eastern white cedar) that when the center of old trees rot completely away, you can often observe several live veins growing from thick roots, each supporting only 1 branch. Most observers would think they were observing a ring of unusually shaped trees if they came upon this interesting occurrence in nature. Given the volume of soil available for root colonization, I just can't see it being a case of one plant outcompeting another, if in fact there really are 2 different plants. I'm pretty close to certain the issue is related to root health. Al

if it wasn't because i can see that the soil is wet, i would say it it looks wilted from underwatering. so maybe you're overwatering it and it's got root rot. dieffenbachia are one of those plants that won't forgive you if you overwater it. however, you also have to make sure that it never goes fully dry and you maintain the soil moderately moist for these. that being said, make sure it's in a pot with good hole/s at the bottom to let it breath despite the slightly damp (not soggy) soil. but one thing is for sure, that plant needs more sunlight (indirect) because not only is it only growing small leaves but it has lost all its variegation. if you want to maintain it in a darker part of the house, it needs at least a lamp near it, but at least 6 inches away, because even cfl bulbs can scorch leaves like sunlight.

Could be a sign that it needs water, but if it's only a couple, I'm confused. Agreed, a photo of the whole plant would help. And check if the soil feels dry to the touch