You’ve done your best to keep your Dieffenbachia happy – so why does it look like it’s crying? If your plant seems to be oozing drops of moisture, it’s natural to wonder whether something is wrong with it. This odd behavior is common in Dumb Canes, but is it cause for alarm?
Don’t worry – a little water dripping from your Dieffenbachia’s leaves is normal and doesn’t necessarily indicate a problem with your plant. This phenomenon is called guttation, and it occurs even in perfectly healthy Dumb Canes. Its actual function is up for debate among botanists, but it seems to have something to do with how these plants regulate the balance of moisture and minerals inside their bodies.
You should check to make sure the fluid isn’t excessively sticky. If it is, it could be a secretion from harmful insects rather than guttation. No matter what, be careful not to get it in your mouth or eyes; the fluids inside a Dumb Cane contain irritating chemicals. We’ll explain how guttation works in more detail below, along with some related care tips.
Why Do Dieffenbachias Weep?
Houseplant owners unfamiliar with guttation will often refer to it as “weeping”, “crying”, or “sweating”. Of course, your Dieffenbachia doesn’t have tear ducts or sweat glands, so where are these mysterious droplets actually coming from?
Guttation occurs when your Dumb Cane has a high internal pressure due to the amount of moisture or the concentration of nutrients inside its tissues. To relieve some of that pressure, the plant releases some fluid from a structure called a hydathode. These are specialized pores that tend to cluster at the leaf margins, which is why the drops on your Dieffenbachia typically show up at the tips and edges of the foliage.
This process is different from transpiration, the evaporation of water from the stomata (the tiny pores on the surfaces of leaves). Transpiration is how plants pull water and nutrients up from the roots; it happens during the daytime, and it’s faster in hotter and drier conditions. Guttation, on the other hand, tends to occur when the stomata are closed for the night, or when the air is humid enough that moisture can’t evaporate quickly.
The liquid that your Dumb Cane releases during guttation isn’t pure water – it’s a substance called xylem sap that’s found in the tissue your plant uses to transport moisture through its body. Note that this is different from phloem sap, the thick, sticky stuff that most people picture when they hear the word “sap”. Xylem sap contains very few sugars – it’s mostly water, minerals, and plant hormones.
Guttation is also different from dew, which is formed when water vapor condenses out of the air onto plants and other cool surfaces, typically during the night or the early morning. It’s easy to confuse the two, though – in fact, the beads of moisture that show up on grass stalks in the morning, which most people assume are dew, are often really droplets of sap from guttation.
Dew doesn’t generally settle indoors, so unless your Dieffenbachia is right by an open window, the moisture you’re seeing is probably from guttation.
Is Your Dumb Cane Weeping Because You’re Overwatering?
As a caring houseplant owner, you’re probably a bit concerned by any unexpected behavior from one of your green pals. And if you’re familiar with the problems of overwatering and root rot, all that talk about excess internal moisture may not have calmed your nerves.
Though some guides on plant care suggest that guttation is due to excessive soil moisture from overwatering, the science doesn’t seem to back that up. Many indoor gardeners have observed guttation in plants that are otherwise completely healthy. If anything, it seems to be correlated with high humidity, which is good for tropical plants like Dieffenbachia.
If your Dieffenbachia is dripping water but shows no other indications of overwatering – such as yellowing, browning, or wilting foliage – then it’s probably fine.
That said, it’s never a bad idea to take an inventory of your care practices. After all, if high humidity is causing your Dumb Cane’s guttation, it could also increase the risk of overwatering – moisture in the potting mix takes longer to evaporate when the air is humid.
Pay attention to the conditions in your Dieffenbachia’s pot, and never give it more to drink until at least the top two inches of the soil have dried out. For a little more accuracy, you can probe all the way down to its roots with a soil moisture meter or just an unglazed wooden chopstick. If it’s still soggy 5 or 6 days after the last watering, you might want to move the plant to a brighter location or transplant it into a potting mix with better drainage.
As a rule, it’s better to water in the morning than in the evening, because the plant will have more time to absorb and dissipate the moisture through transpiration. And you should hydrate your Dumb Cane less often during the darker, colder parts of the year. It’s not growing as quickly, so it doesn’t need as much water.
Mineral Salts and Your Sweating Dumb Cane
Because the sap that Dumb Canes release during guttation often contains mineral salts, it may leave behind small deposits of crusty white material when it dries. In most cases, this is harmless. You can always wipe it off with a wet cloth if you find it unsightly.
If you’re seeing large amounts of this residue, it could be a sign that your Dieffenbachia’s potting mix contains an overly high concentration of mineral salts. This is usually a result of long-term fertilizer use, though it could also be due to watering your Dumb Cane with mineral-heavy tap water.
Salt buildup in the potting mix can damage your Dieffenbachia’s roots, so if you suspect this is happening, you might want to flush the pot out with distilled water. Pour water slowly into the soil, letting it soak through and drain out the bottom. Keep going until you’ve washed enough through the container to fill it up four or five times over.
Minerals, Mealybugs, and Dripping Dieffenbachias
The combination of white salt spots and droplets of fluid can sometimes resemble an infestation of mealybugs. These nasty critters, which look like little bits of white fluff, anchor themselves to your plant and suck out its juices. They’re harmful to your Dumb Cane’s health, and they excrete a clear, sugary fluid called honeydew which can serve as a breeding ground for mold.
Under a magnifying glass, you should be easily able to tell the difference between a crusty patch of salt and a mealybug, which looks a bit like a pill bug covered in flour. Honeydew is also much gooier than xylem sap.
If you do find a clear, sticky fluid on your Dieffenbachia, you may have an infestation of mealybugs even if you can’t easily spot any of the actual insects – they like to hide in small crevices within the foliage. Scale, a closely related type of insect pest, also produces honeydew, as do aphids.
We have a detailed article on battling common Dieffenbachia pests, but here’s the short version: pry off any bugs you can spot with a q-tip soaked in rubbing alcohol, then spray down your plant with a solution of warm water, mild liquid soap, and neem oil.
Use ⅓ teaspoon of soap and 1 teaspoon of neem per liter of water, mixing in the soap first to help the oil emulsify. Then spray your Dumb Cane from top to bottom and let it dry off. You’ll probably need to repeat these treatments every few days for at least a couple of weeks to get all the bugs.
There’s no need to panic just because your Dumb Cane is shedding a bit of water. Kudos to you for paying attention to your plant’s condition, though! That’s the most important virtue for a houseplant owner to have. Keep observing and learning from your Dieffenbachia, and you’ll be able to help it flourish into a mature, healthy, beautiful plant.