The plant is in pretty good condition, it is normal for old roots to rot off and die. Provided the plants grows new roots at regular intervals all will be well. You need someone to tell you how often to repot Phalaenopsis. Tell us where you have the plant and the temperature ranges there, to provide clues re. No flowers.

I'm not sure what you are seeing that I'm not seeing. The roots look fine. Why did you unpot it? Was something going on above the soil line that didn't seem right? The plant looks ok to me as well, so I'm curious. It looks like a very healthy root system... You know, one of the earliest things I read about Hoyas was to not disturb their root system unnecessarily. I've grown a lot of succulents over the years as well, and when you repot a succulent, you can whack away at the roots and do no harm. But I was always told when you repot a Hoya, it's best to disturb the rootball as little as possible - just plop it in a bigger pot and add soil and let it settle in. It takes a LOT of messing to get every bit of soil off a rootball, so I would expect it to go dormant for awhile now. Of course, that may have already happened just because of the change in environment... Denise in Omaha

Phosphorus and potassium are both very helpful for roots (both according to what I've read and what I've experienced with potassium—and according to what I've read with phosphorus, but I imagine it's true). Too much nitrogen can be bad for roots, as can too much water, too little ventilation, diseased soil, etc. When I started plants indoors, I used to give them potassium sulfate, and they would get awesome roots pretty fast. I also did this for cuttings rooted in soil, and for transplants, and it was helpful. I didn't experiment with phosphorus much until I stopped starting seeds indoors. I'm not saying that potassium and phosphorus do what hormone rooting powder is supposed to do, but at least potassium is still helpful for cuttings rooted in soil (it helps them to absorb more water and be less prone to shock—and at least by the time they do root, it helps the roots). I found it to be extremely helpful (both for seedlings and cuttings, but avoid soils with big chunks of partially composted wood chips). I took loads of cuttings in early 2015 with a very high success rate (e.g. tomatoes, watermelon, muskmelons, cucumbers, peppers, tomatillos, etc.) If you give cuttings bright light too soon after you take the cutting, it can stunt and/or wither and/or kill them. Give them at least a day or two of dimmer light. I did pretty large cuttings every time, though (between 3 and 16 inches). Maybe the reason people tend to use younger shoots is to avoid the light issue—but you can definitely take longer cuttings involving older growth. I'd usually take maybe an 8-inch tomato branch, put it in a cup with Nature's Brand seedling mix (with basalt rockdust and some kind of maybe natural 10-10-10 fertilizer added—it was a safe kind for seed-starting and taking cuttings), plant the stem near to the bottom of a 20oz foam cup, and water with water that has a good dose of potassium sulfate in it. Then I'd keep it out of bright light for a couple days, and then put it in bright fluorescent light, or a south window. They generally took a few days (~4 to 8) to root and start growing (for tomatoes; some other things took longer). You don't need hormone rooting powder for the plants I rooted (although you might for some species). If you believe in rooting things in water, it takes some faith to try rooting in soil, but it really is easier (especially in the long run). It's way faster, too. You can have a nice plant in no-time. Just be careful about damping off—you really need to avoid that (it afflicts both cuttings and seedlings). Fresh soil, clean containers, plenty of light (especially 2700k fluorescent light, for some unknown reason, and brighter south window sunlight), ventilation, and a high soil line can help to avoid damping off disease. I'd do a few things differently if I were to take cuttings now (I'd probably experiment with using wood ash instead of basalt rockdust and potassium sulfate, and I'd do some judicious pruning of the old leaves before transplanting the rooted cuttings to the garden; I wouldn't add 10-10-10 fertilizer, because I think it caused more mold or something, although the plants did enjoy it). I would add a small fan to my growing area, and maybe use heat mats where helpful (while keeping the air cooler than I had it). I'd probably give more attention to fewer plants, instead of packing loads of them in close proximity. I'd probably use smaller foam cups (and not start my plants so early). The wood ash could help pests/diseases not be as much of a problem. I used the same soil and amendments for seedlings as I did for cuttings.

update -- this morning I looked again, pulling up all roots -- the roots were barely there anymore! I couldn't find any of the small tan/brownish bugs I saw yesterday, but I did see a winged bug running around (fortunately not flying.. yet), and oddly a few small threadlike white worms. I bagged the whole thing in a sealed trashbag and am deciding what to do. I'd love to save a cutting or two, but not at the risk of infecting other plants.. would rinsing off a cutting or two be enough? Any advice on how to preemptively treat other plants that may have been exposed? I was going to try and pick up some beneficial nematodes this weekend as I read those may help small infestations. Advice is appreciated!