There isn’t a sure-fire way to get watermarks on leaves. Sorry.
Tbh, I’m more likely than not to just…leave them, because they’re not hurting anyone, and getting rid of them can do more harm than good.
But if you do want your leaves to look pristine, there are some things to can try.
By the way, my spellcheck keeps insisting that water mark is all one word, which it isn’t. We’re talking about water residue on plant leaves, not adding something to an image to make it harder to forge. But sometimes the red line gets to me, and I accidentally ok it.
Why does my plant have water marks on its leaves?
There are a couple of reasons that your plant has water marks on its leaves:
Mineral deposits have built up in the leaves
Most water (apart from distilled, I think) has some minerals dissolved in it. If there’s too much building up in the plant, they’ll expel them through the stomata.
This is fairly unavoidable, but some plants do it more than others. Pilea peperomioides almost always have some mineral deposits on the underside of the leaves, and white streaks on the leaves.
If this is happening to you a lot, and you think it’s having a negative effect on your plants, then it might be worth switching to filtered or rainwater.
DON’T use a water softener or something like that. You’ll end up poisoning your plant with the salts that they use.
You’re spraying water on your plant
One of the problems with misting your plants is that you’re (probably frequently) pouring water on your plant. Because you’re only spraying a tiny amount, the water isn’t always heavy enough to run off, so water settles on the leaves. Best case scenario is water rmarks on the leaves, but you can also end up with fungal or bacterial infections (the plant that is, not actually you) that will thrive in moist environments.
What do hard water marks on plant leaves look like?
I’m not bragging here, but I don’t have any plants that have bad water stains at the moment. The water in this part of Yorkshire is pretty soft, so we only really get them on new plants.
The best I could find was this Synonium Mottled, which only has quite faint water marks. It’s those little white spots.
WAIT!
I forgot about the most water mark-y plants of all – fuckin HOYA.
Here you go:
Will watermarks on leaves cause damage to the plant?
In general, no. If the watermarks are so bad that they’re stopping your plant from photosynthesising properly, you’ve probably already poisoned it by watering it with very mineral heavy water.
Water marks aren’t very aesthetically pleasing, but the plant doesn’t care how it looks.
If you have a plant with delicate leaves, bear in mind that some ‘cures’ for water marks on leaves will do more damage than the marks themselves, so don’t try this out on any plants that you’re super attached to, and always test it out on an inconspicuous leaf first.
The good news here is that in my experience, hard water deposit stains tend to show up more quickly and obviously on plants with thicker, more succulent leaves, which will be able to handle more of a through scrubbing than, say, a maidenhair fern*.
*That being said, my maidenhair fern DOES have mineral deposits on the end of its leaves, but I just leave them. For one thing, it’d take hours to clean off each individual leaf, and the plant is so delicate I’d end up doing way more harm than good.
How to remove water marks from plant leaves
In short, you’re going need to dissolve the mineral deposits using some type of acid. Lemon juice, lime juice or vinegar will all do fine.
A note before you begin: you may notice that if you wipe down your plant with a damp cloth, the mineral deposits will disappear. You’ll get all excited that you’re done, only for the plant to dry and the deposits to reemerge. You will need to use something to actually remove the deposits.
I would start by adding a few drops of your acid of choice to some water, and gradually increase the dosage if the marks aren’t shifting.
I’m not a huge proponent of using distilled water, BUT this is one of the few times I definitely think it’s worth using, purely because you’ll be pretty sure you’re not making the issue actively worse whilst you’re trying to make it better.
Gently wipe your plant’s leaves with the water/acid solution, paying attention to the areas that are most stained. Then make sure to clean the leaves because we don’t want them being damaged by the acid.
In an ideal world, you’d spray them down with a shower hose or something, but again, you could end up adding more water stains, so wiping them down with a clean cloth is probably more sensible.
If you do choose to hose your plant down, be sure to dry it properly.
I hope this was helpful to those of you that hate seeing water marks on your leaves. As I said, the watermarks shouldn’t harm your plant, so leave them be if they don’t bother you.
That being said, if you notice an increase in water marks it might be worth looking at changing the water you use, or reducing misting (if that’s something you do). If you do want to mist your plants, use distilled, or at least filtered water, and you’ll reduce the chance of getting hard water stains.
Thanks for the suggestions. My issue is mineral buildup is from an external source. I added a little waterfall to help increase humidity and add a little tranquility in a cluster of plants. I had it running full blast and when I went to water I was shocked to find my Calathea musaica (Goeppertia kegeljanii) and a Birds-nest Fern (Asplenium antiquum) absolutely covered with an opaque layer of white. I guess I’m going to be using filtered water (maybe even distilled) in the water feature from now on. Meanwhile, a few of my plants will get spa days with the solution and cotton balls
Oh no! There’s a garden centre near me that have this same issue – all the plants end up covered in the mineral build-up. Filtered water is probs the way to go.