Do Pothos Cuttings Really Boost Propagation Success?

It usually starts with good intentions. Someone posts about their struggles to water propagate an indoor plant and various plant influencers and the hive mind will usually responds that the "trick" to success is to place a pothos cutting into the water to speed-up rooting. The proffered advice often includes some mention of the pothos cutting releasing valuable rooting hormones that help drive success.

Simple, elegant, and reassuring. Repeated so often over the past 40 years that it feels like one of those pieces of plant wisdom everyone agrees on.

Except agreement is not evidence, and this advice is not truly helping anyone.

Once you slow the story down and look at what actually happens inside a plant cutting, the pothos-in-the-jar hack stops feeling like established plant science and starts looking like something much more familiar: another well meaning piece of advice that is simply myth.

If the advice is questioned at all, the typical response is, "well, it works for me."

Got Things to Do? This is For You!

• Pothos cuttings do not meaningfully boost rooting hormones in plant cuttings
• Auxins are transported inside plant tissue, not through shared water
• Most cuttings that root with pothos present would have rooted anyway
• Light intensity, oxygen availability, and energy usage matter more
• This myth survives because success is assumed, not proven

How The Pothos Propagation Myth Took Root

The pothos propagation myth, like many other origins of myth, feels convincing because it is built from a few true statements.

• Pothos cuttings do root easily in water.
• All plants use hormones to initiate roots.
• External rooting hormones can help certain cuttings root faster.

Individually, none of these facts are controversial.

The leap to myth happens when those singular ideas get stitched into a story that feels logical but skips a critical step. The assumption is that a pothos cutting releases rooting hormones into the water, that those hormones remain active, and that nearby cuttings absorb enough of them to change their cellular behaviour and abilities.

That might sound plausible, but unfortunately, it just isn't supported by the biological process of how plants adapts cellular purpose and actually work.

What Rooting a Softwood Cutting Actually Requires

Hormone generation is not a favour a plant offers. It is a purely selfish survival response.

When a cutting begins to form roots, it is doing something complex and inherently risky. It is reorganizing the nature and purpose of internal cellular tissues, spending lots of stored energy, and committing to new growth without any guarantee that external conditions will support it. For a plant, it is a necessary gamble in the quest to survive.

Inside the cutting, several things must align for success to happen, and none of them are optional.

Cells near the cut site have to abandon their original role and take on a new one. Tissues once dedicated to water or nutrient transport or structural support must dedifferentiate and reorganize, essentially rewinding their DNA and cellular expression/identity so they can participate in root formation. That shift is metabolically expensive and tightly regulated. It does not happen simply because water is present.

At the same time, localized internal hormone concentrations must rise within that tissue. Auxins need to accumulate in the right place, at the right concentrations, and survive long enough to signal specific cells to begin forming root primordia. Too little, and nothing happens. Too much, or in the wrong location, and the signal chain breaks down. This is a local conversation within the cutting, not a broadcast message drifting in from the surrounding aqueous environment.

All of this change and adaptation has to be paid for.

While roots are forming, the plant cutting has no way to replace lost energy. Photosynthesis is often limited, respiration continues, and stored carbohydrates are steadily consumed. If those reserves run out before new roots become functional, the cutting does not fail dramatically. It simply slows, stalls, and declines in ways that are easy to misinterpret.

Then there is the environment pressing in from the outside.

Light has to be sufficient to slow the carbon drain without pushing the cutting into stress. Water must be oxygenated enough to avoid hypoxic damage to developing tissues. Temperatures need to stay within a narrow range where metabolism proceeds efficiently without accelerating depletion. When any of these factors overwhelm the process, rooting does not stop outright. It becomes weaker, slower, and less resilient.

Root formation, like most growth for a plant, is a balancing act performed under constraint. When it works, it does so because internal signals and external conditions align, not because a neighbouring cutting donated minimal hormonal help.

Auxins such as indole-3-acetic acid act locally within plant tissue, creating gradients that signal specific cells to form roots. They are not meant to drift through water and coordinate growth between separate plants. If rooting hormones worked best through shared water, propagation trays would look very different in commercial greenhouses who propagate millions of herbaceous plants every year.

Why Auxins Are Not Floating Around Helping Neighbours

Auxins are powerful hormones, but they are also very fragile and extremely particular.

Auxins degrade quickly in UV light. They break down in oxygenated water (oxidation). They're only beneficial at specific internal concentrations. They must be recognized inside the right tissue, by cells already programmed to respond. Without that necessary alignment, the hormone has no effect, regardless of how much is present. Kind of like using the wrong key to open a lock. It doesn't matter how many wrong keys you try, the door isn't going to open.

Any auxins that may leak from a pothos cutting into a jar of water would be diluted almost immediately.

To put that in perspective, effective root initiation inside a cutting requires localized auxin concentrations in the micromolar range, roughly 10⁻⁶ to 10⁻⁴ molar, and often much higher when rooting hormones are applied directly to the cut surface. In English this means that effective auxin signalling operates at concentrations thousands to millions of times higher than anything that could persist in shared water after dilution and degradation.

A jar of water with a pothos cutting in it is simply not able to change much. Imagine putting a single drop of food colouring into a hot tub. The coloring is there, but the water isn't going to change colour in any meaningful way.

Any hormones leaving the pothos cutting are dispersed into hundreds of millilitres of water, reducing its concentration by orders of magnitude. UV Light and dissolved oxygen further degrade these auxins rendering them even less effective. What remains, if anything remains at all, is measured in very minute trace amounts that fall far below the threshold required to initiate root formation in another cutting.

In other words, even under generous assumptions, the numbers do not work. The signal is too weak, too diluted, and too unstable to matter.

That is why commercial rooting hormones are applied directly to the cut site of hard to root woody plants and never added to shared water resources. Plant biology demands a local spike, not an uber-faint background presence. Think sunlight compared to starlight.

Why Pothos Cuttings Often Look Like the Heros

Pothos earned its own propagation reputation honestly. It just did not earn it the way this propagation myth tries to suggest.

Pothos tolerates water propagation well because its nodes readily form adventitious roots, its tissues cope better with low oxygen conditions found in water, its carbohydrate reserves are generous given its tissue structure, and its growth rate is forgiving under lower light intensity.

That combination makes pothos look unstoppable.

• It roots quickly while other cuttings often hesitate.
• It maintains chlorophyll counts while other plants yellow.
• It survives long enough to become part of the story.

If you took probability and statistics courses, or chose science over PE in high school, then you should know that correlation does not imply causation.

Why This Pothos Cutting Myth Feels Like Proof

This pothios myth sticks because it aligns perfectly with how people evaluate plant success.

Most houseplant cuttings can root without help, especially if environmental conditions are optimal. Dropping a pothos cutting into the jar feels like you're doing something, so when roots appear, your intervention gets credit. When nothing was added, the same success feels passive and less worth remembering. These are psychological aspects that many marketing strategies exploit for gain.

Timing plays a role too. Rooting does not follow a strict schedule. A difference of a few days might feel meaningful and significant when you've taken direct action, but the timing likely falls well within normal variation ranges.

What Actually Improves Water Propagation

If you want better results, there are no shortcuts. There are only constraints.

The cuttings that root fastest and transition best tend to share the same conditions: enough usable light to support carbon balance, temperatures around 20–25°C (68–77°F), clean oxygenated water rather than stagnant low oxygen jars with occasional water top-ups, mature nodes with adequate energy reserves, and a transition into a similarly structured substrate.

None of those variables are improved by adding a pothos cutting. None.

Why This Myth Matters More Than It Seems

On its own, the pothos myth is harmless.

The real issue is what it encourages. It shifts attention away from measurable conditions that can be managed and controlled by the plant parent and toward perceived tricks and hacks. It encourages people to wait for the magic to happen instead of adjusting light, temperature, or oxygen availability, and actually making something more likely. It replaces biological understanding with popular, but false reassurance.

That is how plant care myths persist for decades, and why the PHA was formed.

The Bottom Line on the Pothos Myth

Adding a pothos cutting to a water propagation jar feels actionable. It sounds helpful when you're telling people how well it works with the false confidence the masses have helped cement in your care routine.

It unfortunately just does not hold up when you look at the facts surrounding how hormone concentrations work within plant tissue, and how existing cells transform with exacting standards to create new meristematic tissue.

There is no demonstrated mechanism, no supporting research, and no meaningful advantage for using a pothos cutting to improve rooting success. If you ever find any, please pass along the link.

The myth survives because pothos root easily, not because it helps anything else do the same.

If you want propagation success that lasts, focus on light energy, environmental conditions, and seedling transition.

FAQ

Has any research shown pothos helps other cuttings root?
No. There are no peer-reviewed studies supporting cross-cutting hormone effects in shared water.

Can auxins move through water at all?
They can, but not at stable or biologically useful concentrations for this purpose.

Why do commercial growers not use this method?
Because it offers no control and no consistent benefit.

Why does it sometimes seem to work?
Because most cuttings root anyway.