I'm thinking fungal infection due to poor drainage, but we need more info to be sure. What kind of drainage does the pot have & what sort of potting mix are you working with? Does the pot have drainage holes? An absence of rocks in the bottom? Sufficient air around the roots? How often are you watering?

I bought pots with drainage holes. I'm using miracle grow potting mix. No rocks at the bottom.

Thanks for the awesome tips! I will definitely put them to use.

I am not following. We have what we call pathos growing in aquarium water. No soil. No drainage.

But I was still wondering, why new cuttings that don't have roots look like the pictures above after about a week? My cuttings in water do fine if I let them callous a little after cutting them from the mother-plant. I'm having problems with cuttings with no roots and planting them in soil.

What kind of soil is it? From outdoor garden?

I'd unpot it all, wash off the roots, discard the old mix & start anew. Using Cactus & Succulent mix, combined w/ Perlite (equal parts of each), should make a better beginning.

@carolina, rooting in soil is difficult. You need to be sure that the cutting has a root nub of an aerial root. You need to coat the cutting with either cinnamon powder or rooting hormone to stop fungal rot from killing the cutting before it can get established. And you have to control the humidity religiously. I've only had -- marginal -- luck with rooting herbs in damp soil in an almost-sealed ziploc, and even then it wasn't great success. I think my indoor temps were too warm, as this was the height of summer and we get 2 full months of killing heat (highs above 100F).

I will say though that pothos can live happily in nothing but water and occasional fertilizer. They're tree-dwelling epiphytic vines in the wild and don't really need dirt at all, just tree-borne forest detritus and water. Good luck with the rooting experiments!

The roots that grow in water adapt to the water. They are different than roots that start in soil. Roots of all plants in soil must have oxygen. The stems are diseased from too much moisture. Pothos are a plant I think of as drench and drain plant. So you water really well, and then let the plant go dry down about 25% of the pot. For me this means when it's dry to the touch and I use a chopstick and stick it down to the roots, if it comes out dry = water, if it's moist at all = wait a day or two. Healthy plants need this dry time as much as they need water. When you water, lift the plant and feel it's weight, to use as a reference for how it feels when wet. Now when, it feels dry to the touch lift again. Soon you will get a feel for the weight and the look of the plant and know when to water and will not need the extra step with the chopstick. Keep in mind it will dry more quickly while growing over spring/summer. Plants use more water when they are growing, so you cannot schedule watering all year, it will change. Never get comfortable trusting a schedule, you always have to make the judgement if it is thirsty or needs to be left alone. I think that the care we often find for pothos makes them sound like they want more water than most plants. That's not so in my house. If your soil remains very wet in 4 or 5 days, the soil is holding too much water and needs to be grittier.

So, from what everyone has said...I need to repot my plants, a soil that provides more oxygen, test soil dryness with a chopstick or skewer, and use rooting hormone to stop fungal rot.

Any advice to help pothos to grow new leaves?

How much and what kind of light is it getting?

There isn't advice specific to helping grow leaves.

We've given advice to try to help you help the whole plant. Respectfully, what you'll need beyond what was just recommended is time & patience.