Monstera deliciosa have a habit of dripping water in the morning.
This is a perfectly natural, healthy process that is NOT an indication that there’s anything wrong with your plant.
It is annoying though.
Right, let’s dive straight in:
What is guttation?
Guttation is the process of excess water being forced out of the edges and tips of Monstera (and other plants) leaves through organs called passive or epidermal hydathodes.
Monstera absorb water through their roots. If they absorb too much water, the pressure in the plant becomes too high, so it can be released through the hydathodes.
Fun fact: hydathodes, unlike stomata, can’t open and close, and are a popular entry point for pathogens.
Botanists don’t actually know much about hydathodes, since there’s been relatively little research done on them, apart from in a few food crops, such as wheat. Research into aroids is extremely lacking (because they tend to be pretty difficult to get to, not particularly useful, and usually inedible).
Is guttation dew or sap?
No, guttation is water being released from the plant out of the holes in the leaf edges. Dew is atmospheric moisture that forms on plants as water vapour condenses on cold surfaces.
Technically, guttation is sap, as it has low volumes of nutrients in it. It’s actually xylem sap, containing sugars and potassium.
However, guttation isn’t sticky sap – it’s pretty much the same consistency as water. If your plant has sticky sap on it, that’s more likely to be the result of extrafloral nectaries, and they’re common on Philodendron.
Extrafloral nectaries are organs that produce sugary sap, intended to attract bugs like ants. There are various theories as to why so many plants (over 90 flowering plant species exhibit extrafloral nectaries) wish to attract ants, but no one really knows. Some people believe plants can absorb nutrients from ant nests, others believe ants will eat pests (in which case, why fill them up on sap?)
As far as I’m aware, Monstera deliciosa don’t produce extrafloral nectaries, so if your Monstera is sticky, it’s probably from an external source.
Is guttation the same as transpiration?
No:
- Transpiration is the process exiting through the stomata, guttation uses hydathodes
- Transpiration happens during the day, guttation happens at night
- Transpiration involves water loss through the leaf face, guttation happens at the leaf edges
- Transpiration works with water vapour, guttation with liquid water
- Transpiration involves pure water, guttation water contains salts and sugars
- Transpiration happens regardless of humidity, guttation occurs in higher humidity
- Plants can stop transpiring by closing their stomata, whereas hydathodes are permanently open
Why do plants guttate?
The main reason plants guttate is so that they don’t explode overnight.
Jokes, jokes. We don’t actually really know.
This is what we do know:
If the air is particularly humid, or the soil is particularly damp, the plant can end up taking in too much water. The usual point of exit would be through the stomata, but stomata are closed at night.
The main purpose of stomata is to facilitate gas exchange during photosynthesis, and since the plant isn’t photosynthesising at night, it makes sense to close them. Open stomata can welcome diseases, so makes sense to close them.
Guttation is thought to be the plant’s way of regulating water pressure at night when the stomata are closed – that’s why you usually see Monstera dripping water first thing in the morning.
However, the amount of water lost due to guttation is minimal, especially when compared to the amount of water that can escape via the stomata.
Scientists believe that guttation and epidermal hydathodes serve another purpose, because the risk involved in having constantly open pores is huge, and the amount of water lost to guttation is minimal.
Why can’t the plant just expel excess moisture in the morning?
Or open the stomata when the pressure builds too much?
Why bother having holes in the leaf edges that could let in disease when plants don’t really need them?
Studies (ok, two, which is hardly conclusive) seem to indicate that guttation can help protect plants from predation and disease by carrying pathogen-fighting proteins in the guttation liquid that also deter herbivores.
Another study showed that if the plant had its hydathodes blocked and therefore couldn’t guttate, the plant’s ability to transpire was halved. Do we know why? We do not. We have no idea. And since I couldn’t find a more recent study than 2014, I don’t think anyone really cares. Never mind.
Is guttation a sign of overwatering?
No. Guttation is extremely common in healthy Monstera that have not been overwatered.
Monstera are less likely to guttate if their soil is dry, and tend to guttate immediately after they’ve been watered.
If your Monstera is guttating, that’s not a sign that it’s been overwatered.
However, if your Monstera is guttating every day, that could be a sign that it’s staying too wet for too long.
The good news is, you still have time to check. If root rot had set in, then the roots will take in less water (because the rotten ones will no longer be functioning) and your Monstera won’t be dripping water.
How do you stop guttation?
It’s best to let your Monstera guttate – remember the study that found that reducing guttation also reduced transpiration and therefore photosynthesis?
However, there are things you can do to reduce it:
The easiest way to stop guttation is to keep your Monstera in a dry environment – so dry soil with low humidity. Make sure the soil is incredibly well-draining, and just moisten the roots everyday with a sprayer, rather than watering them properly. You’d also need to keep humidity low.
Unless you’re extremely diligent at keeping the roots damp, you’ll end up doing more harm than good.
You could try keeping your Monstera in water – mine definitely guttates less in water, but it doesn’t stop completely. Weirdly, plants in semi-hydro guttate just as often as plants in soil.
In the experiments I mentioned before, the scientists either physically blocked the hydathodes or increased the atmospheric vapour pressure deficit – i.e. lowered the humidity.
Should you wipe off guttation?
I don’t, preferring to remove it with my arms as I brush past my Monstera with my morning coffee. It’s not necessary to dry your Monstera’s tears (or sweat, or pee, or however you like to look at it) but the fluid does contain salts that can leave white marks on the ends of your leaves.
I’ve never had an issue with Monstera getting guttation marks, but I have from Alocasia.
Are there any side effects of guttation?
Other than potentially marks on your Monstera leaves and marks on your furniture, I don’t think so. However, since we know so little about guttation, perhaps there is!
However, in the wider world, it’s thought that bees can die from drinking the guttation drops from plants that have been treated with imidacloprid. So if you use systemic pesticides on your Monstera, don’t let any bees near it in the morning (source).
There are also studies that seem to say that allowing guttation water to fall back into the soil can reduce nitrogen uptake by the roots. However, these studies do state that further research needs to be done (source).
So in conclusion:
- Guttation is perfectly natural
- It doesn’t necessarily mean you’ve been overwatering
Before you go, here are a couple of articles you might find interesting:
I enjoyed this article very much Very helpful and entertaining!
Thank you so much! I’m glad you enjoyed it.
Very useful and very funny!
Thank you, glad you enjoyed it!
Great article.
Thanks!
Oh thanks for this!! I bought my first monstera a few weeks ago and gave it a good watering a few days ago, and woke up to what looked dew drops this morning. I checked in case I’d left the window behind it open all night – nope. Water leak from the apartment above? Thank god, no. So reached for trusted Google and found your helpful article. I feel much better now. Have a great day!
I’m glad I could set your mind at ease! Good luck with your Monstera, may it grow big and strong.
I put my varigated monstera outside for a few hours so it could get some “fresh air”. Unfortunately, it was windy and the new, beautifully varigated leaf broke off. 🙁 The plant has been weeping for a day now and I am very glad to have found this. Thank you!
oh noooo what a nightmare! Don’t worry, that scenario is one that wild Monstera will come across all the time, so the plant will survive. You can put the leaf in water – they last a pretty long time.
Sometimes single leaves grow roots and will last even longer, but unless there’s a node there, it’ll remain a single leaf.