Maybe once I'm a more advanced orchidician I'll understand how to use it better. I am considering its usefulness as a top dressing on my 'chids to help keep humidity up; it's around 20% humidity in my home, dry as a bone. I'm worried it'd cut down on air circulation and cause root rot (again!) on them.

Sounds like well-reasoned advice to me. Fall and winter are times when you want to disturb roots minimally, though potting up is fine if roots are excessively tight. If you DO pot up, though, be extra cautious about how you water. Your plant will probably sulk for a while after the trauma, then grow rather slowly until the vernal equinox fully wakes it up, so over-watering will be something to actively avoid. Al

Try using a "tell" to tell you when it's time to water: Using a 'tell' Over-watering saps vitality and is one of the most common plant assassins, so learning to avoid it is worth the small effort. Plants make and store their own energy source – photosynthate - (sugar/glucose). Functioning roots need energy to drive their metabolic processes, and in order to get it, they use oxygen to burn (oxidize) their food. From this, we can see that terrestrial plants need plenty of air (oxygen) in the soil to drive root function. Many off-the-shelf soils hold too much water and not enough air to support the kind of root health most growers would like to see; and, a healthy root system is a prerequisite to a healthy plant. Watering in small sips leads to avoid over-watering leads to a residual build-up of dissolved solids (salts) in the soil from tapwater and fertilizer solutions, which limits a plant's ability to absorb water – so watering in sips simply moves us to the other horn of a dilemma. It creates another problem that requires resolution. Better, would be to simply adopt a soil that drains well enough to allow watering to beyond the saturation point, so we're flushing the soil of accumulating dissolved solids whenever we water; this, w/o the plant being forced to pay a tax in the form of reduced vitality, due to prolong periods of soil saturation. Sometimes, though, that's not a course we can immediately steer, which makes controlling how often we water a very important factor. In many cases, we can judge whether or not a planting needs watering by hefting the pot. This is especially true if the pot is made from light material, like plastic, but doesn't work (as) well when the pot is made from heavier material, like clay, or when the size/weight of the pot precludes grabbing it with one hand to judge its weight and gauge the need for water. Fingers stuck an inch or two into the soil work ok for shallow pots, but not for deep pots. Deep pots might have 3 or more inches of soil that feels totally dry, while the lower several inches of the soil is 100% saturated. Obviously, the lack of oxygen in the root zone situation can wreak havoc with root health and cause the loss of a very notable measure of your plant's potential. Inexpensive watering meters don't even measure moisture levels, they measure electrical conductivity. Clean the tip and insert it into a cup of distilled water and witness the fact it reads 'DRY'. One of the most reliable methods of checking a planting's need for water is using a 'tell'. You can use a bamboo skewer in a pinch, but a wooden dowel rod of about 5/16” (75-85mm) would work better. They usually come 48” (120cm) long and can usually be cut in half and serve as a pair. Sharpen all 4 ends in a pencil sharpener and slightly blunt the tip so it's about the diameter of the head on a straight pin. Push the wooden tell deep into the soil. Don't worry, it won't harm the root system. If the plant is quite root-bound, you might need to try several places until you find one where you can push it all the way to the pot's bottom. Leave it a few seconds, then withdraw it and inspect the tip for moisture. For most plantings, withhold water until the tell comes out dry or nearly so. If you see signs of wilting, adjust the interval between waterings so drought stress isn't a recurring issue. Al

If someone is trying to override a plant's natural rhythms by controlling day length (actually it's the length of the dark period) it will be necessary to eliminate all sources of natural light. Case in point. I grow tropical trees indoors under 6500K LEDs on timers set to 16/8. Of the 6 windows in my basement, 5 are covered and the 6th is behind a clothing storage rack that nearly blocks all light passing through the window such that I cannot comfortably move around the basement unless I have the grow lights on or other lighting is switched on. Still the plants, even dormant or quiescent plants, know perfectly well when the Vernal Equinox is nigh, which is clearly evidenced by their wanting to begin growing in earnest. I think, since I'm always more interested in discussing what's best for the plant, it's rather meaningless to debate how much one might be able to deviate from acting in the best interest of the plant and still get away with it. More often than not, 'grower convenience' and 'best for the plant' are mutually exclusive, which is why I almost always view things from the plant's perspective with little regard for what the grower's druthers. When growers are provided good information backed by sound reasoning, they generally don't require being talked into doing right by the plant. I tend to never repot out of season, only exception being when I'm very sure an intervention is required because it's highly unlikely the plant will survive until the timing is more opportune for repotting. I'll leave it to each individual grower to decide what care regimen is more appropriate, but to me it seems a prima facie case that working to avoid additionally stressing plants already low in vitality in favor of waiting until the plant is at its strongest AND entering the most robust phase of the growth cycle, is much to be preferred to 'do what you want, when you want'. Finally, trees and herbaceous plants prioritize their parts, but perhaps it's better to say that the strength of energy sinks (where plants allocate food/energy) has a distinct pecking order: Energy is first allocated to respiratory function, i.e. to maintenance of living tissues, then, to production of fine roots, followed by flower and seed/fruit production, then primary growth (extension of both roots and shoots), then secondary growth (thickening), and finally, the synthesis of defensive chemicals. If you repot a plant out of season, it can take months for the plant to return to the state where it is synthesizing protective chemicals; whereas, it takes only weeks after serious work like repotting and hard pruning is completed after giving careful consideration to timing. "To every thing there is a season, and a time to every purpose under the heaven: A time to be born, and a time to die; a time to plant, and a time to pluck up that which is planted;" Al