The human tendency to over-water plants | Hacker News Reader

The human tendency to over-water plants

dirtwise.substack.com

220 pointsrichardatlarge106 comments

This comes to me in right time. I recently witnessed a small miracle. There is a dragontree of quite concider able age. Its long mostly leafless branches showing that it has had chaotic life. I got it from friend who rented next door and placed it into small corridor. And then at one point I forgot about it and in the spring sometime it dropped off all leaves. I concidered it as dead. I was really frustrated -- I've killed a creature with my carelessness.

It was like this for months. And since it was quiet corner of a corridor, I forgot it again, let it sink to me and from time to time remind me to become better. I pushed away dealing with it, since my own carelessness was thrown at me and it bit as pain. Until a day, when I saw green leaves popping out of it's tips of branches again -- it's alive. I'm still not sure how it got to life again, since I didn't water it. Maybe the heat of the summer, and it was much heat, and little moisture from air. But it was my salvation.

I need to find the best place and right soil for this honorable plant and of course learn to water it. So this piece of information falls into right soil. Thank you for sharing :)

By dragontree - do you mean Dracaena cinnabari by any chance? While there are other Dracaenas the island of Socotra where D. cinnabari was found is basically an exposed rock off the cost of Yemen ... think sun all day with little water. There's a great paragliding(?) video of the island on Youtube. Check out a native observation: https://www.inaturalist.org/observations/68966536

I think it's Dracaena Marginata I have. Not 100% sure, since it totally lives outside it's normal environment in northern Europe, so it's thin and naked, so visual similarities may be deceptive. :)

Dragon trees - Dracaena marginata - are damn hard to kill. If they don't have water, they don't die - they just stop growing. I actually let a weed grow in the pot of mine because the weed responded much more dramatically to soil conditions.

Like all plants, however, they do need sunlight. Is your corridor well lit?

Not too much. It got some afternoon/evening sunlight. Not too much directly. But I will move it to a better place once I get done with my renovation works.

After you said it, I also started to wonder whether they are die-hards, because what's the chance of wonders, eh? :) Probably the just drop the leaves and stay in hibernation until environment gets better. I'm so glad I didn't get rid of it because of my ignorance.

My dad was visiting recently and watered one of my old dead bonsais and said sometimes you water them and they come back.

That plant didn't come back (yet?), but not a week ago I am planting some new flowers I got on sale and I see that a plant that I had written off as dead a year ago was actually had a green stalk still at least up to the soil line. I've seen plants survive and come back from a lot, but nothing like this. I'm going to keep watering it and hopefully it will grow a new stalk and come back to life!

I hooked up soil moisture meters whose data is exposed in an API, which is read by an arduino board that activates micro pumps from a reservoir after a threshold (customized per plant).

I love the juxtaposition of the simplistic suggestions from the article vs this comment.

It’s not a nightmare, I simply hook up individually customized Arduinos to every house plant!

Totally not like turning your house plants into Borg drones.

Could potentially put them on motors and pick up on stress hormones to allow the plants to move to better location.

Skriders! Entities cut from this very cloth appear in Vinge's "A Fire Upon the Deep," one of the great achievements of human imagination.

https://archive.org/details/fireupondeep00ving

Hexapodia as the key insight.

> where are all your plants?

> We had a fight and they moved out

Real life miniatures for this one-page RPG perhaps? https://diwatamnl.itch.io/bonsai-brawlers

Man I really love Hacker News sometimes

Is it bad that I added an audio storage chip that plays "feed me seymour" over and over until the plant is watered?

Also the juxtaposition of how cheap plants can be and the price of a single arduino setup in this case…

I can get 10 Wemos D1 minis delivered for $20 and 30 cheap soil sensors for around another $20. (Chosen for wifi connectivity which bare Arduino lacks. One micro can monitor many sensors, but most don’t want a bunch of wires everywhere.) It’s often the case that it costs more for the power source than the micro and sensor.

These aren’t Arduino brand arduinos just like your office xerox isn’t necessarily made by Xerox.

the sensing side is reasonably easy, but the automatic watering gets hairy. OP was proposing one pump+reservoir for each plant, which adds up the cost and makes powering the system more demanding. And you probably want some sensing in the reservoirs too so that they don't run dry. Alternative would be to do plumbing to create a water network, but that brings its own challenges especially in residential setting where plants are scattered all over the place.

> and 30 cheap soil sensors for around another $20.

Where do you get them?

AliExpress or anywhere else cheap electronics components are sold. (Haven’t looked, but I’ll bet dx, taobao, banggood, and the others also all have them. Amazon and EBay are often faster and cheap-enough now that ePacket has been nerfed. Search something like “soil sensor 10pcs”; looks like they’re $12-13 for 10 there.)

They’re cheap to make (basically just a small PCB with a few passives and a connector) and while they don’t last a long time in some soils, they’ll last long enough for you to learn what you want and then decide if you want to change sensors every year or three, go higher quality, or find another way to estimate evapotranspiration and water based on open loop control and monitoring (which is what most people likely end up doing, either technically or by human approximation).

If you (or anyone else) is in, or willing to go to, the edge of Cambridge, MA, I’ll set a couple aside for you for free.

Yes, why doesn’t everyone just do this?

Because Blumat exists, and there's something incredibly elegant in how these things can adjust dripping or pull water from a container without any electronics, and depending on the version either with a single moving part or no moving parts at all.

I’ve tried both blumat and arduino style watering, in the end the water can is the simplest and most reliable. Sometimes technology doesn’t enhance things e.g. the soil moisture sensor gets wet, doesn’t give good readings, hard to calibrate etc. Blumats are very sensitive to tuning mistakes, can dump gallons on a plant in a few hours and don’t distribute the water well but only water one small spot

Can you show details of this

How is that working out for you? I've heard that soil moisture meters can be wildly inaccurate. Have you found one that's reliable?

Finally a good solution proposal. Which components do you use?

Here’s the bulk of it: https://www.amazon.com/dp/B07LCNKC6N

But I use different moisture sensors: https://www.amazon.com/dp/B0896R33V8

And extra wiring/tubing because of my distance requirements

For how much ? Every time I look into getting sensors for my plants the price for something wireless puts me off :/.

You only killed several hundred other plants (in the form of resource extraction and refining) to do this!

Good soil moisture meters are expensive and cheap ones don’t work

My peace lily is the most low maintenance, easy growing plant I have. When it's thirsty it visibly droops, give it a quick blast and a few hours later it's perked back up.

My rosemary on the other hand, I couldn't keep it alive no matter what I tried. Full sun, partial shade, inside, outside, letting the soil dry out, moderate watering, daily watering, I tried it all and none of it helped.

Agreed. My peace lily is great. It wilts when it's thirsty, and otherwise it requires no maintenance.

I once left it for about a month, came back, it had wilted quite a lot. I thought maybe it wouldn't recover. I watered it a normal amount and woke up to it having perked up quite a lot, and in another day it was back to normal.

Definitely a plant I would recommend.

Be careful with lillies if you have cats.

Peace lilies are not actually lilies in this sense, so aren’t especially harmful to pets[1].

[1] https://www.petpoisonhelpline.com/poison/mauna-loa-peace-lil...

things i didn’t expect to learn on hacker news… thanks :)

Spathiphyllum belong to a pretty evil big family and are poisonous as all good Aroids are. You can expect a combination of microscopic crystal arrows tearing flesh and acid being throw in the wounds later for maximum fun.

We have it indoors exactly because that (being poisonous are often left untouched by animals increasing its decorative value). Can kill a cat by asphysia perfectly but this is really unusual. Pets can eventually bite them, once, and learn fast not to do it again. The dangerous part is if they would swallow 'a chunk of burning fire'. Will not happen easily unless your dog or cat is a totally clueless idiot.

Peace lilies and Zebra plants both do this. At our shop, I refer to them as "drama queens" as they do let you know when they need water.

Another interesting one is fittonia (or nerve plant). It recovers readily as well.

My Fatsia Japonica does the same. Stalks will droop over and the thing will look like it has no structural integrity. Water, and tomorrow it's fine.

the structural integrity is indeed provided by the capillary action of the plant tissue drawing up water and stiffening the stems

> drama queens

I say the same thing about my Peace Lily. Actually, her being so dramatic trained me to water all my plants more regularly. Yes I'm admitting that I was trained by a plant lol :D

Succulents are also a good choice, they can tolerate quite a long time without water. The advice for them it let the soil dry completely, and then give a complete soak.

I have mine in a semi-transparent container with no drain, so I can see the soil get darker, and I know when to stop adding water, and since there is no drain it soaks up the water well (i.e. the sponge hydrophobia the article mentions).

Funny, I couldn't kill my rosemary bush if I wanted to. It sits at the corner of the house without water and it grows and grows. In SoCal btw

3 months ago I had a massive, overgrown 7 foot rosemary bush in my backyard drastically cut down to about 3.5 feet. It was so tall it was crushing itself under its own weight.

One summer later and it’s back to around 5 feet. Also in SoCal, it gets watered maybe once a month, if that (whenever I remember). I _wish_ I could stop it.

Spathiphyllum dislike cold and people messing with their roots when repotting. Apart of that they are low maintenance and also known to remove toxics like formaldehyde and trichlorethylene from the air in labs and rooms.

Rosemary needs dig deep in the soil or in a big clay pot. Die in a day with their roots cooked if left in small plastic black pots. They need also full sun, but not when you buy it. Only after they develop its roots and pass the shock of being moved from a greenhouse to scorching sun. Big Rosmarinus plants have a bigger rootball and are much easier to keep alive.

I got a peace lily in March after my father passed away and it has been so much trouble to keep it going. I'm really sad about it.

First I didn't realize I was overwatering it and introduced root rot into the system. The online guides recommended repotting with fresh soil and carefully yanking on all the rotted roots so as to remove as much of the rotted material as possible.

They also recommended a very gentle scrubbing with a tiny bit of dish soap with the expectation that the plant will be shocked for a while but recover. I did all this and it did help somewhat.

Then the following months the area was very sunny with 90 degree F days. I didn't realize it at the time but I was killing the plant by overheat.

2-3 weeks of this and after realizing what was happening, I moved it into the basement near a tiny window with indirect sunlight (~69 degree F all day). This worked for a while but now as I take a step back and look at the plant, it is a mess. It is definitely still alive but does not seem healthy at all. Multiple leaves have yellowed, some have either yellow or black spots on it. All of the beautiful White Seed like things have turned pitch black and are disintegrating.

I am now just not sure what to do, I just keep watering it with 1 water bottle's worth of water every three days or so but it seems like it is a mess that I can't recover from.

I feel you. My son may be in this position one day. Don’t give up on it! I’ve kept multiple peace lilies in offices and homes for years. They are dramatic, but also forgiving. What you’ve done so far sounds helpful. I’d suggest:

* More light, but indirect. They like well-lit rooms as long as the sun doesn’t shine on them. They do like 70º better than 90º. * Let the soil dry a little between waterings. Stick your finger in the soil to see if it’s damp. If it is, water in a few days. * It’s ok to overwater them until water runs through the pot, but be sure the pot doesn’t sit in that water. * Prune off all the dead material. The blooms always look disgusting when they die.

Lastly, get it a friend or two. Get another couple peace lilies and care for them the same way. It’ll help you understand how they behave.

I've been there. I received a peace lily seven years ago when my brother passed away and I had a hard time keeping it healthy. I tried keeping it inside and all it was doing was dropping leaves. I tried putting it near a window to no avail. Its death seemed inevitable.

Then I tried putting it outside. What I've learned is that while they do not do well in direct sun, they do like light. Lots of it.

I've read that a southern window is the best window for a spath. The reasoning is simple: for folks that live in the northern hemisphere, the most amount of indirect light will enter from the south. And wouldn't you know it -- our south wall has no windows!

I live in Tennessee and I now keep mine outdoors during the growing season. It sits in a pot on the deck underneath the canopy of a large river birch. Even during the 90+°F days, it does well. The back of our home faces west, so it can catch a few direct rays late in the day as the sun sets over the horizon, but it is strategically located so that the deck railing and a nearby crape myrtle filters enough of that scorching late afternoon sun to make it happy.

I bring it indoors once the overnight lows start to dip to around 40°F. Over the winter, it drops about a third to a half of its leaves. I put it back out for a few days at a time in the early spring as weather allows. Once the frost danger has past, it stays outdoors. The leaves rapidly multiply and it puts out about 5-6 blooms around July.

If you can, try putting it outside. I am sure that the boost in photosynthesis will help it more than anything.

I give mine a pint of water every week or two. If it wilts I water it regardless. It's been happy in a bright room near a sunny window in the UK for 10 years. Current pot is around 10" diam and 10" high for comparison.

If ever in doubt I let it tell me - it's all about the wilting, if it starts to wilt, give it water, if it's not wilting, you can wait, if you haven't seen it wilt for a while, might as well let it dry some more to avoid root rot. I also trim off dead flowers and leaves just to give the other leaves more light but I don't think that matters.

Yellowing and leaf decay in fall is a common symptom of cold. Needs a warmer place.

Yeah, I have a balcony that's a plant kill zone (north facing high rise in Australia, so lots of sun, the odd 40 degree (100 farenheit) day, aircon outlet there pushes it up much hotter still.

Peace lilies have been surviving (not thriving, but surviving) there for 8 years now, but I've tried and killed rosemary three times now. I suspect overwatering is the cause.

All of these in pots, btw, because balcony - suspect that the rosemary would be easier in the ground.

Yeah I have one of these, its so overdramatic when it's thirsty.

We over-water because we fear the watering isn't enough, we care for the plant. Just like parents' unconditional love for their children.

But it hurts them when it's too much and it's never intentional.

So true.

I hope you're talking to someone professional about it. ;-) /jk

This is even more the case with cacti and succulents, otherwise you just literally spoil them.

From what I learned, the article has some bad tips and is overly verbose...

Do NOT let your plant sit in water over night. You need a good soil mix, which does not compress and regulates moisture. Water plenty, true, but dispose the water collected underneath the pot. Plants rely on flushing out excess salts and so on with rain (which is also why artificial watering will ruin soils in agriculture over time). Letting them sit long in the soup will disable this process and overtime the soil will kill the plant, e.g. starting with yellow-brown leaf tips.

Just put a finger in the soil to check humidity. Water when two thirds feel dry. works for most plants.

The hard part about watering plants is the "not every day; not rarely" schedule. A 3-4 days period is just shit for forming a habit.

As others have said, e.g. a dramatic plant like a Peace Lily can remind you to care for your plants. But use the finger to check the other plants to make sure they are dry enough.

Or get a snake plant (Beamtenspargel). They are really hard to kill.

One of the things this guide is missing is to consider the kind of soil you’re using. I love Haworthia, a kind of succulent. However if you try to give them the succulent soil from a big box store, your first watering (even to a bone dry soil) will likely be fatal simply because the soil will retain too much water. Plants sensitive to too much water also need soil that retains very little water, sometimes even a medium with no soil at all (also called a gritty mix)!

Yep I too err on the dry side by using

1. Planters with several holes that I drilled 2. Soil that I mixed for better drainage

A thirsty plant is better than rotten plant

I can't be bothered to water different plants on different schedules, so I water everything once a week. Instead I vary the amount of water and if plants look wet I skip them for that week. Seems to work.

I use an app on my phone called Planta [1] that creates a water, fertilize, mist, clean and prune schedule for my plants which I tend to follow. You add your plants to the app, it asks a couple of questions such as which type of pot is the plant planted in and which room* is it located in.

I share the same account on the app with my wife and we can stay logged in simultaneously, which helps to keep track.

The app is only free for the watering schedule, the rest are premium features which you need to pay for.

* You can create rooms and describe the sun light exposure of those rooms.

[1] https://getplanta.com/en/about

I learned this this year when I started from zero to about 40 species of plants.

Most of them are either succulents or semi-succulents (like peperomias).

It took me some time to really understand how little water they need.

Now most my succulents and peperomias live in a substrate that is basically small rocks of which some have ability to wick and soak a little bit of water.

Once the plant is established, I put the pot with the plant in an inch of water for couple of minutes once a week and this seems to be enough for most succulents.

I thought about overwatering plants and I think this comes from me trying to be good to them. Plants need water and so by giving water I feel like I am being good to them. It takes some willpower to overcome this tendency.

An article that doesn’t only tell you what to do, but goes out of its way to explain the reasons and discusses your doubts before you even knew you had any. Well written.

Living in a Northern country with limited sunlight, I've found that generally it's best to err towards too little watering than the other way around most of the year. I've killed many plants by watering them too much in winter when there's lack of light, but most my of my plants have survived quite severe drought when I've been away during summer.

Kind of makes sense right? Sometimes it doesn’t rain for weeks but the plant still has to survive. Then it rains for a whole day and plant is completely soaked, still survives.

I guess the biggest problem plants have is that humans want to interfere with their natural cycle :P

Aspidistra performs well in very low amounts of light. Can be left dry for a long time also. Except for the alien's egg shaped flowers is a little boring but is a survivor.

In any case the solution if you tend to over-water can be to stop it... or to keep over-watering. Just find plants that like having their feet soaked. You can't over-water a Zantedeschia if the temperatures remain warm. If you forget it and let it dry it just will go to sleep for a while and will flower better. You can't over-water a Cyperus.

Tangential: Last year I dug out a plot of soil, put a mesh fence around and under it to keep animals out, mixed in some fertilized dirt from the hardware store with the ground soil when I put it back in, and put some assorted seeds spaced around in it (tiny hole with a few seeds, I forget my exact spacing), all allegedly planted at an acceptable time and in the right climate zone. I watered it according to what the internet said was correct, a deep soaking every 4-5 days I think.

Nothing grew but the peas. Eating those few peas felt like the scene from that Disney movie where Donald Duck is slicing one bean into nearly invisible portions for everyone.

I don't know what I did wrong but all that physical exertion for nothing has soured me on gardening a bit. This year I just gave up and threw some pre-potted plants in the ground and they all thrived but it feels like cheating.

Can anyone weigh in? Is growing from seed just something best left to real farmers?

Most recreational gardeners I know that grow from seeds, including myself, start the seeds inside and then plant them outside. That doesn’t explain your initial lack of plant growth, but it is a useful technique.

Well, growing seeds definitely requires more efforts and care, for instance I had 3 or 4 failed attempts with extremely vulnerable tobacco seed, which was very counter-intuitive since adult plants are quite sturdy. Pea seeds are ultra-sturdy, that's why you succeed.

BTW, seeds would like to have some assistance, like soaking them before planting, then planting them at fake soil (eg. wet cotton wool)

Also, I highly recommend peat bricks for seedlings like https://www.growbarato.net/24393-large_default/peat-foam-eco...

Pre soak is not nessisary or often helpful. I think https://www.gardenmyths.com/ had an article on that at some point

A lot of seeds don’t need frequent watering to germinate. One heavy water to start and then keep it damp, not wet. If the ground is too cold many seeds will just rot. Seed trays make it easier to manage the temperature and water. Beans in particular like one watering when planted and no more until they germinate.

4-5 days is not enough watering for outdoor vegetables. Seedlings need watering every day or better 2x a day. Use hose or sprinkler drip irrigation doesn’t work with seedlings

Also timing is critical you need to plant at the right time for your local area otherwise seeds will .

Light level is important too, full Sun IS best but requires constant irrigation for best results.

Research a lot ask your neighbors and keep trying

Try reading https://www.gardenmyths.com/. There are some decent YouTube channels like urban farmer curtis stone but YouTube is kind of a slow repository of info. You need to watch a lot of videos to learn bits

Since I've made my raspberry pi plant watering pump my indoor plants have be growing very consistency with much bigger leaves. It's also an added bonus that I don't have to worry about my plants when I'm traveling. To make things simple the pump is directly powered by the 5v usb port. The only downside right now is that since the pump is triggered by the usb port of the pi, by default the usb power is turned off, this is achieved by turning off the entire usb controller and turning it back up using a cron job when the plants need to be watered (3secs every 3 days). There is no setting to turn off the usb controller when the pi boots by default, it can only be turned off once the pi is fully booted. This is fine as long as the pi stays running. However, since in California we've been having power outages, which cause the pi to reboot and water the plants for an extra 10 seconds or so every time.

The watering scheule isn't the nightmare, the insects are.

mosquito dunks

i've found springtails are nearly indestructible

On a side note, those are cool when filmed in super slow mo/close up, saw YT video

hah, feast your eyes my dude https://www.youtube.com/watch?v=7iPosKLguoU

apparently these are Lepidocrytus Springtails https://bugguide.net/node/view/928438/bgimage

Oh damn, I actually thought they looked like silverfish

I'm thinking of a different insect, it looks more like a ball/can jump really high

The problem I had with my indoor garden were the gnats, so mosquito dunks killed em off

My bell peppers [0] are growing hehe

[0] https://i.imgur.com/jUNnWIi.jpg

Which is great since they are beneficial

I've read that, but I've also read that it depends on what's available for them to eat, and they'll also chew on roots if they need to.

I'm rather busy person, yet I'm enjoying watering my plants, it is a part of being plant owner.

The only possible problem arises when I leave my house for several weeks and then intravenous droppers comes to the rescue.

I agree that watering only when the soil is completely dry is best. It's really hard to tell when that is with large plants thou. I have a massive monstera and a mid sized ficus. I can't pick these up to check their weight. Why are there no smart plant meters? Something I push into the soil and sends me a notification when the soil has completely dried out?

I've used those analog two prong moisture meters, but I'm looking for something that can just sit in the pot permanently..

There are, like the Xiaomi Mi Flora sensor (I think) or something like April Brother soil moisture sensor.

I have given up on those though because they're to expensive to put in every pot, and if they're not in every pot then I might as well manually check all the pots.

the two prong ones are resistive, and the exposed metal does indeed corrode quite quickly when in use.

there's also a single-prong capacitive type, only very marginally more expensive, with all metal parts covered in plastic film, which can sit in the soil indefinitely.

A convenient prong you can push into the soil is your finger - if it comes out with soil particles stuck to it, the plant doesn't need watering.

I do that quite a bit, but I have pots which are 12 inches deep. I want to know when the bottom has dried out.

Moisture meters aside, I use plants as an example of the “expert problem”. Experts give advice that seems helpful, but only if you have intuition already.

“Completely dry” (or “plant is not hefty”) is not helpful to a beginner. There is basically a continuum of dryness, and with large plants, there’s a gradient as well (as you mention).

Paraphrased conversation I have had: “How much should I water this plant?” “Some, but not too much”