Normally, a plant produces more energy (photosynthate - sugar/carbohydrates) than it needs to keep its systems orderly. Whenever it has a surplus of energy, the plant makes new cells in which the energy is stored - that is how the plant grows. If your plant is stalled (as far as growth is concerned), it is either making just enough energy to keep its systems orderly, or not enough. In the case of the later, not enough, it would be shedding parts - usually leaves, but entire branches are often shed by plants that branch.

The 2 things that come to mind when growth conspicuously stalls are: root congestion (rootbound), poor root function due to soil compaction or an unfavorable amount of air and water in the soil - usually too much water, or root disease.

'Growth' is a measure of the plant's increase in dry mass. Often, a plant might have branches or stems that are extending, but the plant might not be technically 'growing' if it's shedding the same amount of dry mass it's producing by way of extension (stems/branches getting longer). That's why I didn't consider a deficiency of nutrients or light as the reason your plant stalled. Low light might stop growth, but it doesn't stop extension. Plants will continue to extend until they have depleted all their energy reserves, even in the dark; and, the plant has mechanisms in place that allow it to 'steal' nutrients from other plant parts to fuel new growth.

We can eliminate root congestion as cause for the stall because we know the roots didn't suddenly become decongested, which pretty much leaves poor root health or function as the underlying issue; but, that's not to say there aren't compaction or root congestion issues ready to take over the position of 'primary limiting factor' after you resolve any root health/function issues. That's how plants work. Resolving the primary limiting factor issue makes something else the NEW primary limiting factor.

Over-watering is the most logical suspect. The root system's finest roots do the lion's share of the plant's heavy lifting. Over-watering and the accompanying lack of oxygen kills the finest roots and limits the root's ability to function normally. The plant has chemical messengers that keep 'plant central' informed about the relationship between root and shoot volume. Root growth always precedes top growth, so, when roots die from poor conditions in the root zone, the plant's messengers tell it to focus energy allotments on the roots only, until the volume of healthy roots can provide water/nutrition for any increase in top volume.

My best guess is, you over-water, which kills roots and stops top growth. Then, before enough air returns to the medium to allow normal root function, you water again. If something happened to extend the interval between waterings, you would expect to see at least extension growth. Taking a vacation or skipping a watering when you thought you watered would produce a positive result if you're over-watering. Also, the low humidity that occurs indoors with central heating operating can notably decrease the appropriate interval between waterings, which would also be a positive if you're over-watering.

You can get your watering under control by using a 'tell' to 'tell' you when it's appropriate to water. More about using a 'tell' just below.

See this for an outline you might find useful.

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 air (oxygen) in the soil to drive root
function. Many off-the-shelf soils hold too much water and not enough
air to support good root health, which is a prerequisite to a healthy
plant. Watering in small sips leads to a build-up of dissolved solids
(salts) in the soil, 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

Thank you for the response! My watering strategy for the Dracaena is to wait until the leaves, which are normally standing upright like they are in the picture, droop. That's usually once a month in winter and twice a month in summer when the house heats up. I knew next to nothing about plants in middle school when I did the repotting, and the pot I chose back then has no drainage holes (which is why I'm considering a new pot and new soil) so I lean towards underwatering and wait for visible signs of thirst. The roots appear to be working fine, since it's a very noticeable difference between drooping (all leaves pointing down, but not completely limp) and upright (like the picture) and the transition between the two takes six to eight hours.

Is waiting for it to be visibly thirsty like that hurting it? Should I be checking more regularly and watering before it gets to that point? And should it be fertilized regularly? As far as I know (mom may do things when I'm not looking...) it's never received anything except tap water (I know that's not the best for it, but it doesn't rain much and I can't really afford bottled water).

Is waiting for it to be visibly thirsty like that hurting it? Yes, but not as much as keeping the soil overly moist could or would. We have a tendency to believe that, because plants A and B TOLERATE consistently wet soil, they like or prefer it. The reciprocal of that, because plants C and D TOLERATE going completely dry between waterings, the plants prefer it. This leads growers to believe all sorts of misconceptions about media/soils, watering habits, fertilizing strategies, ..... . Ideally, your plant would like to be watered just before it starts to suffer drought stress, so, before leaves lose turgidity and wilt occurs. Should I be checking more regularly and watering before it gets to that point? If the pot your plant is in had a drain hole, the answer would be yes. Since it doesn't, you're better to wait for wilt to occur or use a 'tell' to 'tell' you when the soil is dry, and water then. It's not ideal, but in your case (pot with no hole) the lesser of two evils is the better strategy And should it be fertilized regularly? Yes, but the 'yes' needs to be qualified. Many if not most growers will advise you shouldn't fertilize during the winter, but that's a horticultural myth born of the fact that most growers are growing in water-retentive soils that force the grower to water in small sips, this, to avoid the negative effects that occurr when media hold an excessive amount of water for extended periods. When you water in small sips, the practice ensures "all" salts not used by the plant from fertilizer solutions and tap water remain in the soil when water evaporates from the soil - nowhere else for them to go. An excess of salts in the soil A) makes it more difficult for the plant to take up water, and B) causes a skewed ratio of nutrients in the soil, which leads to both toxicities and deficiencies. Where I would normally advise you to use a medium you can flush with each watering (without having to worry about the negative effect of an excessive amount of water I mentioned above), you can't do that w/o a drain hole in the pot. You should probably withhold fertilizer until the plant is in a pot with a drain hole. As far as I know (mom may do things when I'm not looking...) it's never received anything except tap water (I know that's not the best for it, but it doesn't rain much and I can't really afford bottled water). Tap water is fine, but it can be high in dissolved solids (minerals) like calcium, magnesium, iron, sulfur, ..... . Because these minerals are left behind in the medium when water evaporates, it's best to flush the soil regularly to rid it of the accumulation of these dissolved solids.

You might wish to consider drilling a hole in your pots, adding a (water) collection saucer under the pots, and adding some blocking between the pot and collection saucer so the effluent exiting the drain hole has no pathway back into the soil. IOW, the pot shouldn't, at any time, sit in the water that exits the drain hole.

This might be helpful, too.

Al