13 ms·

Why is houseplant advice so bad?

172 points by richardatlarge 5y ago

stevespang 5y ago
40 years ago I got my degree in Hort Science., almost all my classmates ended up in other professions, as did I. No one did the research to determine that upon graduation companies wanted to pay you $800 a month to manage their greenhouses. Most consumers do not realize that 99% of all houseplants they purchase at nurseries or stores are heavily contaminated with pesticides, in mass mono cultures you have to do this because the pests explode and ravage the "crops". Houseplants bought from stores are mostly a consumer "throw away" culture. I grew rare plants as a hobby and made a few bucks selling them, and still dabble in propagation of difficult to root species, as well as polyploidy conversion. One interest is growing some of the most fragrant flowering plants, such as night blooming jasmine and sambac jasmine, but these species require rainwater or deionized water so as not to turn yellow due to the alkalinity in most municipal water supplies deactivating the soluble iron (or so I thought deionized water was the key).I installed a RO system I bought off the internet for $300 about 10 years ago with timers and solenoids to fill a 55 gallon drum every day. Then, through experimentation I discovered you could simply acidify the water to just below 7.0 with sulfuric acid bought over the internet, or weaker version through local auto parts store. 1 capful in 55 gallons of water of conc. H2So4, let sit overnight. It's dangerous to handle, it can burn your eyes and hands really fast, so perhaps better for newbies to spend more money$$ on vinegar and use a pH meter off Amazon. Also, organics will generally grow plants faster and healthier, such as homemade compost, bat guano or fish emulsion - - - but fish emulsion smells ugly, so only use for outdoor plants. Champion cabbage growers in Alaska use fish meat scraps mixed into soil to compost to grow prize vegetables. The "bagged" soil mixes at local big box stores are mostly crap, like ground up wood chips. Real bales of authentic sphagnum peat moss 50% with sand 50% should be the starting point of a good soilless potting mix, if money is no object, years ago we found 50% sphagnum peat moss and 50% COARSE vermiculite grew the best plants. You need to sterilize or pasteurize your soil/soiless mixes or you risk fungus, root rots. Commercial growers use lot's of toxic soil drenches to combat root rot. If you sterilize, then you can drench with PreStop beneficial fungus (prebiotic) to try to prevent root rots. There are others, but the research I reviewed showed PreStop performed best. Appears the only folks printing huge money with horticulture are those growing marijuana.
cwkoss 5y ago
How often should houseplants be fertilized? Is miracle grow box accurate or do they tell you to use more than you need to get you to use more?
- Palomides 5y ago
  the article specifically calls out asking questions like this, they're impossible to answer correctly
- lathyrus_long 5y ago
  They should be fertilized at the same rate at which the plants are consuming the fertilizer. Professionals will often judge this by measuring the electrical conductivity (EC) of the solution leaching from the bottom of the pot. The fertilizers are mostly ionic (excluding urea, though that becomes ionic after breakdown to ammonia), so that conductivity is roughly proportional to the root zone fertilizer concentration. These meters used to be expensive, but you can get them for a few dollars on eBay, AliExpress, etc. now. Such measurement is now de rigeur in hydroponics. It works in soil-like potting mixes too, though only the most technically sophisticated hobbyists there (e.g., many orchidists) have adopted so far. http://www.yieryitools.com/sale-9685340-high-accuracy-drinking-water-tds-meter-white-with-titanium-alloy-probe.html http://www.yieryitools.com/sale-9685340-high-accuracy-drinki...
Asparagirl 5y ago
I agree with the author that we need to see more examples of larger, older plants to get an idea of what our lil plant bbs could be someday. Fortunately there are some great Facebook groups for different genera, and of course there’s https://www.reddit.com/r/matureplants/ https://www.reddit.com/r/matureplants/
- richardatlarge 5y ago
  That’s a good link: seeing what plants can become really encourages more interest in keeping them healthy
- reydequeso 5y ago
  Recently visited a local botanical garden and saw their mature Ficus lyrata (Fiddle lead fig) and was astounded to see mine at 6 feet tall was merely a juvenile branch on the entire tree. The author has also a good point in that maturing plants is a lot of work and as they become more of themselves they become more than, imo, what people would consider aesthetically appropriate. M.deiciosa is a hot plant right now and maybe in these 5+1 apartments someone will live in one long enough to let it really start branching up and out and taking up a valuable amount of living real estate. It also has these, to my fiancee, 'penile' roots that are to her unsightly. They make me feel more alive seeing the plant thrive and do its thing.
- ramraj07 5y ago
  Reddit is the only major site that still gets away with outrageously shitty engineering. There’s no possible way to follow this link on iOS. The link shows only a link to open in app but they’re so shitty that it opens the app in the app store not the actual app.
  - TheCoelacanth 5y ago
    No way they're the only one that gets away with it. Shitty engineering is practically the norm for major sites.
millzlane 5y ago
In the cannabis world It's because of 'Broscience'.
- richardatlarge 5y ago
  https://www.urbandictionary.com/define.php?term=broscience https://www.urbandictionary.com/define.php?term=broscience
dredmorbius 5y ago
And of course: in what other domains is this issue present?
- brodouevencode 5y ago
  I think that’s the point everyone replying seems to miss. Finding the right question to frame the problem can be as hard as the problem itself.
  - dredmorbius 5y ago
    Far too many read far too literally, yes.
Dumblydorr 5y ago
Been diving deep into lawn care recently. There's a TON, literally hundreds, of products you can spread on your lawn. There's 250 days of the growing season to apply those hundreds of products on. And does it work? Well, this internet comment written by so and so says it does, and their lawn is beautiful, but which of the 15 things they're doing are most pivotal? Or is it multivariate and all the parameters matter and affect and interact with each other? Unfortunately, I believe it's the latter complex case. pH matters a lot, that affects fertilization uptake, but so does soil bacteria and organic matter, lack of bugs and diseases, proper moisture, and the physical act of cutting the grass is an art and skill, not a mere chore. Oof, plants need a lot of variables to be in the right ranges, and with soil and watering and weather, it's a lot of fluctuation on top of it all.
- colechristensen 5y ago
  This is a problem all over, from health advice to cooking to skincare, lawn care, etc. etc. etc. A complex system with many variables and optimum points trying to be solved with anecdotes, magical cures, and "good for you" products.
  - eru 5y ago
    A good place to study human confirmation bias.
  - Larrikin 5y ago
    Atleast with cooking I've collected a few sources that are consistently good. For new recipes I follow them exactly the first time and disregard any source that has had more than a couple not great recipes, specifically any recipe on all recipes that not a sponsored professional chef.
    - tompazourek 5y ago
      When cooking, we often optimize for flavor and texture. But what about digestion and nutrition and how each person has different preferences and a different body? It starts getting very complicated quite fast, so many variables...
kodah 5y ago
Caring for houseplants is quite hard. I have 8 and my friend recently gave up his job to grow Bonsai trees full time. The amount I learned from him was quite interesting, I almost felt dumb by the end. My plants do fine, but they could've been doing way better. For my Bonsais, I didn't know that they should be given filtered water. The Bay area has particularly nasty water, so immediately my plants were getting spots. Second, when you repot in the summers, the soil should be aligned to where you're growing. Third, East facing windows that cliff the sun at the hottest part of the day are imperative. I then asked him, "Wait, I can't leave them in the same spot all year?" and his immediate reply was, "Hell no, not unless you plan to layer shades in front of them, but I bet that's not why you put them where you did." For watering guidance, he said, "Stick your finger into the soil down to the knuckle, if it's dry, water them. If it's still wet, let it dry out." Keeping plants alive is relatively easy; helping them thrive is another matter entirely.
- omegaworks 5y ago
  >The Bay area has particularly nasty water Isn't Hetch Hetchy water some of the cleanest?
  - whyenot 5y ago
    Yes it is and it's perfectly fine for house plants. TDS (total dissolved solids) is usually below 30 PPM, at least for me. But, there are parts of the Bay Area with less pure water.
    - omegaworks 5y ago
      Oh I didn't know there was such a disparity. Is there a water quality map somewhere?
      - lathyrus_long 5y ago
        Each utility should report water quality. For most of San Jose, it's https://www.sjwater.com/sites/default/files/2021-06/ccr.pdf https://www.sjwater.com/sites/default/files/2021-06/ccr.pdf The parameters relevant to plants (EC, pH, chloride, etc.) are usually in the secondary standards, rather than the primary standards most important for human health. San Jose groundwater is terrible, EC ~ 700 uS/cm out of the tap. I wrote https://hydromisc.github.io/hydromisc/doc/nutrient-calculator.html https://hydromisc.github.io/hydromisc/doc/nutrient-calculato... to model the custom fertilizer blend that I'm developing now, since the cal/mag in the water plus the phosphate from the acid I use to neutralize the carbonate significantly shift the nutrient profile. That's obviously beyond typical houseplant practice, but professionals growing in non-soil media (nurseries, vegetable growers, etc.) do roughly the same.
fargle 5y ago
I dunno, the advice I get from my houseplants always seems spot on...
EastOfTruth 5y ago
house plant care is not that hard to automate (talking about water/feeding)... of course if you are doing bonsai culture, you will have to manually trim it (but I grew bonsai pepper plants with minimal care... no fruits yet though)
throwaway984393 5y ago
Caring for a houseplant is like caring for a baby. There are things that work, and things that don't, but not necessarily for your baby. You won't really know what's going on unless you pay close attention to it. And if it seems unhappy, you won't really know how to make it happy until you try a few things out. Baby advice and houseplant advice isn't "bad", it's just subjective. also: my houseplants don't get big because I don't take care of them! the ones I left outside "to die" have grown substantially... i even left a bunch of succulents outside, that were sitting in pots with no drainage, overflowing with water for 6 months.... they're fine. they "should" be dead as doornails. shrug
- kurthr 5y ago
  Had friends in Hawaii. They had such beautiful indoor orchids that I commented on their green thumbs... to which their response was, "Oh no, we kill them inside and then put them outside to recover and bring back in the ones that are blooming".
- aidenn0 5y ago
  Fortunately my babies have survived much better than my houseplants. My wife and I managed to kill a succulent arrangement by underwatering it.
  - porknubbins 5y ago
    What bothers me is the advice you find all over the internet that "you are probably overwatering your plants" is only correct if you assume the reader knows nothing about plants and just keep them soaking all the time. Overwatering is NOT a Hofstadter's law where it happens even if you try to correct for it. Reality is container plants are a pretty complex system that an amateur is likely to mess up but not always in a particular direction, and the answer is to be anal about watching all the time.
monopoledance 5y ago
Tl;dr: Lots of houseplants die. The end. Anyway, since you are here: You may kill your plants with tap water. Plants evolved to get demineralized rainwater. The salts of tap water will build up in the soil, slowly poisoning the plant. Additionally the pot is also the plant’s potty: It disposes excess minerals and waste through the roots, and expects the rain to flush it away. It’s best to water your plants with demineralized water, but you can also use (old) boiled and cooled down water, which lost at least some CO2 and consequently fell out calcium. In any case, if you water your plant, do so thoroughly, until water comes out at the bottom. Let it collect for a few minutes and then dispose it. Do not let it reabsorb! This will help the plant getting rid of salts and also helps not getting the soil soaking wet. Btw. this is also why irrigation is a problem for food security. Using straight underground water for crops in hot regions will only work for a few years, until the soil is dead for good…. Edit: Oh yeah, and IIRC the snake plants leaf tips are crucial for growth. They may be hurt from handling in the store and will consequently not grow in length anymore. Not sure it has anything to do with watering at all. My snake plant got “store leaves”, which haven’t changed at all over the years, got brown just at the very end, and new leaves, which are almost double the length and totally healthy. Maybe a brown tip is just the normal display of a leaf without a head (cell). Fun fact: Did you know snake plants store “sun energy” at daylight, and then do the rest of photosynthesis at night? So they do not lose water due to evaporation as much, when opening their pores for gas exchange! Pretty cool, eh?!
- Factorium 5y ago
  Doesn't that also flush out any fertilizers added to the soil?
  - monopoledance 5y ago
    Yes, but that's a good thing. You are much more likely to burn your plant with fertilizer, than starving it. If you think about the typical environment most plants adapted to, you will not have a year's worth of N2, P, ... supplied once a year, but a constant, very low exposure through rain and continuous organic decay/production processes in the soil and above. For the most part, plants rely on osmosis, the capillary effect and evaporation to transport nutrients. Salt levels, including fertilizer, modify the osmotic costs and limits.
zeteo 5y ago
I've read the part about roots several times and don't understand it. Is there some intermediate level of actionable advice between "water once a week" and this? If anyone can explain it to me in a way that makes sense to a programmer it would be much appreciated. I do have multi-year surviving house plants but worry about their roots. > This comes about by having the roots well distributed in free-draining soil so that water and oxygen can feed the plant. From this you can infer there might be a problem If water runs right through the pot, and/or you squeeze the pot at its base and it’s rock solid. If so, take the pot off and have a look. From this you can also infer that, repotting into a much larger pot will just leave the roots buried in a mound of cold, wet soil, far from any roots. You might also see that a root-bound plant might not even need to be repotted, or can be repotted back into the same pot.
- richardatlarge 5y ago
  For many indoor plants, soil acts as a porous environment for roots to hang out in, where there’s humidity and air. Too much soil act as nothing but a wet blanket, too root-bound and the roots are not held in soil at all, so are poorly fed. Water only to rehydrate the soil, not to keep roots chronically wet
- adriand 5y ago
  Honestly don't worry about it. If your plants are growing and seem healthy, they are fine. Just ensure your plants have a pot that is appropriate to their size. Off the top of my head and based on my current plants, I'd say a plant that's 1 to 2 feet tall needs a pot around 6 inches in diameter and maybe 8 inches tall. 2 to 3 feet, 10 inches and similar height. 4 to 5 feet, 12 inches and 12 to 16 inches tall. Past that, and you don't need any advice on plants.
- lathyrus_long 5y ago
  I also found that advice about as confusing as all the other consumer-targeted houseplant advice. If you've got some time to invest, then I believe you'll find that advice for professional growers makes a lot more sense, much more quantitative and backed by trials and chemical or biological mechanisms. I quite like: https://www.fs.usda.gov/treesearch/pubs/46345 https://www.fs.usda.gov/treesearch/pubs/46345 That's a guide to operating a nursery, developed by academics seeking to distill the scientific state of the art into something practically useful with basic equipment. Specifically as to judging how much to water, I go mostly by weight. Thoroughly wet the medium until water runs from the holes in the pot, and then don't water again until the weight drops below some fraction (e.g., 20%) of that maximum. You can use a scale, or judge by hand with practice. You can also wait until the plants show drought stress. For example, they might visibly wilt, or succulent leaves and herbaceous stems may go from turgid to limp. That's probably not optimal, but it's better than overwatering. Finally, you can also pot in media with very low water holding capacity, like a blend of normal potting mix and perlite. This makes it near-impossible to overwater, but the tradeoff is that frequent (e.g., every few days) watering then becomes mandatory.
yumraj 5y ago
Orchids are notoriously hard for us, we’ve managed to kill several of them. I guess mostly due to over watering.
- curiousllama 5y ago
  Orchids are notoriously hard in general, to be fair
adriand 5y ago
I have, and have had, numerous thriving houseplants. My largest plants right now are about five feet tall. I also have three orchids that do wonderfully, a selection of cacti, etc. I do still kill plants from time to time but it's rare. In any case, I don't really agree with much of the advice in this thread. In order, the most important things IMHO are: 1) Caring: you actually have to care about the plants. This requires that you notice how they are doing and if they aren't "happy", taking action to try and improve their environment. 2) Light: if the light is bad, you're screwed. People keep talking about overwatering but not providing plants with enough light is just as bad and probably worse. Plants indoor get far less light than they do outdoors. If you have a very sunny room, in most cases the only way plants will do poorly is by totally neglecting to water them. 3) Water: not particularly difficult. With most plants you only need to water when the soil is completely dry. What I would especially suggest you do if you are starting out with houseplants is to purchase plants that show, by virtue of their foliage drooping, if they don't have enough water. The leaves of a peace lily will droop. The leaves of devil's ivy will start looking floppy. I've noticed that my spider plant's leaves seem to become paler. Some plants (e.g. ones that look like palm trees) will lose their foliage, starting at the bottom. In any case, if you have a plant like this, it is visibly telling you it needs water, so it's not hard to comply. It can also serve as a sort of canary in the coal mine for your other plants. That's honestly about it. I repot the occasional plant, and sometimes I do a little light fertilizing. But if you have a plant that is doing poorly, my advice in almost all cases is simple: ensure it gets more light, and don't water it until it's totally dried out.
frazbin 5y ago
Biggest problem for indoor plants is lack of light. Get a cheap photometer and check. Eyes are terrible at judging light intensity.. if the plant never gets light sufficient for basic metabolism, it will die sooner or later. Bare minimum full shade is like 10000 lux.. indoor lighting often doesn't get above 1000.
- onecommentman 5y ago
  And the good news is 4 foot LED tube lights are cheap, inexpensive to run and easy to mount with just two-sided tape. It’s a simple DIY project to mount LED tubes on the underside of a table and put that table on top of another table…and you can grow whatever you like. Plants won’t just survive but actually thrive and flower. Doesn’t look half-bad either.
martyvis 5y ago
The Aussie national public broadcaster, the ABC, has the fantastic Gardening Australia show that has been going for 32 years (in its current format). It's not too pretentious and is full of great technical pragmatic tips from knowledgeable professional horticulturalists and experienced amateurs. You might like this series on indoor plants as we call houseplants. https://www.abc.net.au/gardening/the-great-indoors--containers-and-potting-mixes/12920438 https://www.abc.net.au/gardening/the-great-indoors--containe...
Scoundreller 5y ago
This fellow cuts through a lot of the bullshit on his blog/newsletter. https://www.gardenmyths.com/ https://www.gardenmyths.com/ Unfortunately, there’s often a lack of good evidence except from industrial agriculture.
tdrdt 5y ago
I think one of the biggest misconceptions about plants is: they only need water (and light). Yes plants need water, but they can't grow on water alone. They need all kinds of minerals that are in the soil. When those are gone the plant will die. When you repot plants you add fresh soil so you also add minerals. But when you don't repot you need to add those minerals once in a while. Tip for aquarium owners: a lot of plants benefit from the 'dirt' in dirty aquarium water. An also lesser known fact is that there is a huge symbiosis between bacteria, fungi and the roots. So in fact you also need to keep them alive.
- crooked-v 5y ago
  > Tip for aquarium owners: a lot of plants benefit from the 'dirt' in dirty aquarium water. There are some interesting-looking mini-aquaponics systems out there that could be useful for anyone who already knows how to take care of a fish tank.
- lathyrus_long 5y ago
  If you like aquaponics, then take a look at Goliad Farms. He raises greenhouses full of tropical fish, relying entirely on plants to remove ammonium from the water. And yeah, that root zone microbiome is complex, though somewhat different in containers than in nature. In soil-like potting mix, you're generally guaranteed to have nitrifying bacteria, so ammonium fertilizers are still generally safe to use. (Ammonium can easily become toxic to plants; but soil bacteria oxidize it to nitrate, which plants tolerate in higher concentrations.) Stuff like sulfur to amend soil pH doesn't necessarily work in containers though, since you don't necessarily get the bacteria that oxidize that to sulfuric acid. Nitrogen-fixing bacteria for legumes may also not be present unless deliberately inoculated. The plants would die without that microbiome in nature, but with human help it's not mandatory. Many hydroponic methods run with a root zone that's as sterile as possible, and the only major change required is to supply most (~90%) of the nitrogen as nitrate.
dvh 5y ago
My 2 huge plants (ficus benjamina, 15 years old, grown from 1 tiny branch, and aglaonema, ~40 years old and survived one freezing): https://pbs.twimg.com/media/FC7tsGGWEAkInx1?format=jpg https://pbs.twimg.com/media/FC7tsGGWEAkInx1?format=jpg
- richardatlarge 5y ago
  Nice plants!
TwoNineFive 5y ago
What's that you say? Off topic? Yea I agree, but... As a systems and network administrator I know that the vast majority of outages are human initiated. Maintenance gone bad. Simple mistakes such as unplugging the wrong cable. Stupid stuff. Sometimes thresholds such as disk usage or other resources get exceeded or a part just wears out and breaks, but usually it's us stupid humans fucking something up with our own hands where it would have been just fine if you had left it alone. So there's your servers are houseplants advice. Stop touching them. Stop doing stuff. Leave it alone. Of course that's impossible. We have to get new plants installed and have to find that equilibrium they like to thrive. But when you find it, leave them the fuck alone and don't break it.
timdaub 5y ago
The most bewildering tip I always see and often hear recited is that a plant likes it to be moved/rotated. Like wtf, which plant gets rotated in nature??? Generally, some people like to think they know better what the plant needs than itself. I went from being talked in to overcaring to the probable most careless approach. My plants get water when the soil is dry. That's it. Gladly, I also ended up stopping to interfere with e.g. how they grow and I've now noticed that they started to look "wild" and healthy. Done right, it's a beautiful display of nature.
- sufiyan 5y ago
  Something I learned to do is to only water the leaves (ie make them wet). And if the soil is very dry, to pour water directly to the roots. My reasoning being that rain unless it is heavy, doesn't actually reach the soil directly and then there is the matter of water coming out through the openings in the pot if there is too much of it. I don't know why this works for me.
  - vladvasiliu 5y ago
    > only water the leaves Doesn't this get a lot of water on the ground? Or do you keep your plants in a dedicated area, where water wouldn't be much of a bother? In my case, the plants are in the living areas, on hardwood floors, where I usually walk. I'd hate to get my feet wet every time I walk next to them.
    - sufiyan 5y ago
      Yes you are right in that I have a dedicated place for them. You could try using water sprays instead.
- tgb 5y ago
  I assume rotating isn't for the health of the plant but for giving it a more symmetric and fuller appearance.
  - 5y ago
nottorp 5y ago
> To get an even better answer, ask a better question: ‘I water my sansevieria (snake plant) about once a week, and it’s not in direct sun. I’ve had it for six months and it was nice when I got it. But now the tips are brown, what am I doing wrong?’ Hmm where have i seen that before... oh, here: http://www.catb.org/~esr/faqs/smart-questions.html http://www.catb.org/~esr/faqs/smart-questions.html
- brodouevencode 5y ago
  As I was reading this all I could think was that this should be popped up before any stackoverflow post is allowed to be submitted.
spaetzleesser 5y ago
When it comes to houseplants you just have to ask my mom and you will know everything that’s to be known. If there is a problem she needs maybe 10 seconds to take a look and give you the solution.

40 years ago I got my degree in Hort Science., almost all my classmates ended up in other professions, as did I. No one did the research to determine that upon graduation companies wanted to pay you $800 a month to manage their greenhouses. Most consumers do not realize that 99% of all houseplants they purchase at nurseries or stores are heavily contaminated with pesticides, in mass mono cultures you have to do this because the pests explode and ravage the "crops". Houseplants bought from stores are mostly a consumer "throw away" culture. I grew rare plants as a hobby and made a few bucks selling them, and still dabble in propagation of difficult to root species, as well as polyploidy conversion. One interest is growing some of the most fragrant flowering plants, such as night blooming jasmine and sambac jasmine, but these species require rainwater or deionized water so as not to turn yellow due to the alkalinity in most municipal water supplies deactivating the soluble iron (or so I thought deionized water was the key).I installed a RO system I bought off the internet for $300 about 10 years ago with timers and solenoids to fill a 55 gallon drum every day. Then, through experimentation I discovered you could simply acidify the water to just below 7.0 with sulfuric acid bought over the internet, or weaker version through local auto parts store. 1 capful in 55 gallons of water of conc. H2So4, let sit overnight. It's dangerous to handle, it can burn your eyes and hands really fast, so perhaps better for newbies to spend more money$$ on vinegar and use a pH meter off Amazon. Also, organics will generally grow plants faster and healthier, such as homemade compost, bat guano or fish emulsion - - - but fish emulsion smells ugly, so only use for outdoor plants. Champion cabbage growers in Alaska use fish meat scraps mixed into soil to compost to grow prize vegetables. The "bagged" soil mixes at local big box stores are mostly crap, like ground up wood chips. Real bales of authentic sphagnum peat moss 50% with sand 50% should be the starting point of a good soilless potting mix, if money is no object, years ago we found 50% sphagnum peat moss and 50% COARSE vermiculite grew the best plants. You need to sterilize or pasteurize your soil/soiless mixes or you risk fungus, root rots. Commercial growers use lot's of toxic soil drenches to combat root rot. If you sterilize, then you can drench with PreStop beneficial fungus (prebiotic) to try to prevent root rots. There are others, but the research I reviewed showed PreStop performed best. Appears the only folks printing huge money with horticulture are those growing marijuana.

cwkoss 5y ago

How often should houseplants be fertilized? Is miracle grow box accurate or do they tell you to use more than you need to get you to use more?

Palomides 5y ago
the article specifically calls out asking questions like this, they're impossible to answer correctly
lathyrus_long 5y ago
They should be fertilized at the same rate at which the plants are consuming the fertilizer. Professionals will often judge this by measuring the electrical conductivity (EC) of the solution leaching from the bottom of the pot. The fertilizers are mostly ionic (excluding urea, though that becomes ionic after breakdown to ammonia), so that conductivity is roughly proportional to the root zone fertilizer concentration. These meters used to be expensive, but you can get them for a few dollars on eBay, AliExpress, etc. now. Such measurement is now de rigeur in hydroponics. It works in soil-like potting mixes too, though only the most technically sophisticated hobbyists there (e.g., many orchidists) have adopted so far. http://www.yieryitools.com/sale-9685340-high-accuracy-drinking-water-tds-meter-white-with-titanium-alloy-probe.html http://www.yieryitools.com/sale-9685340-high-accuracy-drinki...

Asparagirl 5y ago

I agree with the author that we need to see more examples of larger, older plants to get an idea of what our lil plant bbs could be someday. Fortunately there are some great Facebook groups for different genera, and of course there’s https://www.reddit.com/r/matureplants/ https://www.reddit.com/r/matureplants/

richardatlarge 5y ago
That’s a good link: seeing what plants can become really encourages more interest in keeping them healthy
reydequeso 5y ago
Recently visited a local botanical garden and saw their mature Ficus lyrata (Fiddle lead fig) and was astounded to see mine at 6 feet tall was merely a juvenile branch on the entire tree. The author has also a good point in that maturing plants is a lot of work and as they become more of themselves they become more than, imo, what people would consider aesthetically appropriate. M.deiciosa is a hot plant right now and maybe in these 5+1 apartments someone will live in one long enough to let it really start branching up and out and taking up a valuable amount of living real estate. It also has these, to my fiancee, 'penile' roots that are to her unsightly. They make me feel more alive seeing the plant thrive and do its thing.
ramraj07 5y ago
Reddit is the only major site that still gets away with outrageously shitty engineering. There’s no possible way to follow this link on iOS. The link shows only a link to open in app but they’re so shitty that it opens the app in the app store not the actual app.
- TheCoelacanth 5y ago
  No way they're the only one that gets away with it. Shitty engineering is practically the norm for major sites.

millzlane 5y ago

In the cannabis world It's because of 'Broscience'.

richardatlarge 5y ago
https://www.urbandictionary.com/define.php?term=broscience https://www.urbandictionary.com/define.php?term=broscience

dredmorbius 5y ago

And of course: in what other domains is this issue present?

brodouevencode 5y ago
I think that’s the point everyone replying seems to miss. Finding the right question to frame the problem can be as hard as the problem itself.
- dredmorbius 5y ago
  Far too many read far too literally, yes.

Dumblydorr 5y ago

Been diving deep into lawn care recently. There's a TON, literally hundreds, of products you can spread on your lawn. There's 250 days of the growing season to apply those hundreds of products on. And does it work? Well, this internet comment written by so and so says it does, and their lawn is beautiful, but which of the 15 things they're doing are most pivotal? Or is it multivariate and all the parameters matter and affect and interact with each other? Unfortunately, I believe it's the latter complex case. pH matters a lot, that affects fertilization uptake, but so does soil bacteria and organic matter, lack of bugs and diseases, proper moisture, and the physical act of cutting the grass is an art and skill, not a mere chore. Oof, plants need a lot of variables to be in the right ranges, and with soil and watering and weather, it's a lot of fluctuation on top of it all.

colechristensen 5y ago
This is a problem all over, from health advice to cooking to skincare, lawn care, etc. etc. etc. A complex system with many variables and optimum points trying to be solved with anecdotes, magical cures, and "good for you" products.
- eru 5y ago
  A good place to study human confirmation bias.
- Larrikin 5y ago
  Atleast with cooking I've collected a few sources that are consistently good. For new recipes I follow them exactly the first time and disregard any source that has had more than a couple not great recipes, specifically any recipe on all recipes that not a sponsored professional chef.
  - tompazourek 5y ago
    When cooking, we often optimize for flavor and texture. But what about digestion and nutrition and how each person has different preferences and a different body? It starts getting very complicated quite fast, so many variables...

kodah 5y ago

Caring for houseplants is quite hard. I have 8 and my friend recently gave up his job to grow Bonsai trees full time. The amount I learned from him was quite interesting, I almost felt dumb by the end. My plants do fine, but they could've been doing way better. For my Bonsais, I didn't know that they should be given filtered water. The Bay area has particularly nasty water, so immediately my plants were getting spots. Second, when you repot in the summers, the soil should be aligned to where you're growing. Third, East facing windows that cliff the sun at the hottest part of the day are imperative. I then asked him, "Wait, I can't leave them in the same spot all year?" and his immediate reply was, "Hell no, not unless you plan to layer shades in front of them, but I bet that's not why you put them where you did." For watering guidance, he said, "Stick your finger into the soil down to the knuckle, if it's dry, water them. If it's still wet, let it dry out." Keeping plants alive is relatively easy; helping them thrive is another matter entirely.

omegaworks 5y ago
>The Bay area has particularly nasty water Isn't Hetch Hetchy water some of the cleanest?
- whyenot 5y ago
  Yes it is and it's perfectly fine for house plants. TDS (total dissolved solids) is usually below 30 PPM, at least for me. But, there are parts of the Bay Area with less pure water.
  - omegaworks 5y ago
    Oh I didn't know there was such a disparity. Is there a water quality map somewhere?
    - lathyrus_long 5y ago
      Each utility should report water quality. For most of San Jose, it's https://www.sjwater.com/sites/default/files/2021-06/ccr.pdf https://www.sjwater.com/sites/default/files/2021-06/ccr.pdf The parameters relevant to plants (EC, pH, chloride, etc.) are usually in the secondary standards, rather than the primary standards most important for human health. San Jose groundwater is terrible, EC ~ 700 uS/cm out of the tap. I wrote https://hydromisc.github.io/hydromisc/doc/nutrient-calculator.html https://hydromisc.github.io/hydromisc/doc/nutrient-calculato... to model the custom fertilizer blend that I'm developing now, since the cal/mag in the water plus the phosphate from the acid I use to neutralize the carbonate significantly shift the nutrient profile. That's obviously beyond typical houseplant practice, but professionals growing in non-soil media (nurseries, vegetable growers, etc.) do roughly the same.

fargle 5y ago

I dunno, the advice I get from my houseplants always seems spot on...

EastOfTruth 5y ago

house plant care is not that hard to automate (talking about water/feeding)... of course if you are doing bonsai culture, you will have to manually trim it (but I grew bonsai pepper plants with minimal care... no fruits yet though)

throwaway984393 5y ago

Caring for a houseplant is like caring for a baby. There are things that work, and things that don't, but not necessarily for your baby. You won't really know what's going on unless you pay close attention to it. And if it seems unhappy, you won't really know how to make it happy until you try a few things out. Baby advice and houseplant advice isn't "bad", it's just subjective. also: my houseplants don't get big because I don't take care of them! the ones I left outside "to die" have grown substantially... i even left a bunch of succulents outside, that were sitting in pots with no drainage, overflowing with water for 6 months.... they're fine. they "should" be dead as doornails. shrug

kurthr 5y ago
Had friends in Hawaii. They had such beautiful indoor orchids that I commented on their green thumbs... to which their response was, "Oh no, we kill them inside and then put them outside to recover and bring back in the ones that are blooming".
aidenn0 5y ago
Fortunately my babies have survived much better than my houseplants. My wife and I managed to kill a succulent arrangement by underwatering it.
- porknubbins 5y ago
  What bothers me is the advice you find all over the internet that "you are probably overwatering your plants" is only correct if you assume the reader knows nothing about plants and just keep them soaking all the time. Overwatering is NOT a Hofstadter's law where it happens even if you try to correct for it. Reality is container plants are a pretty complex system that an amateur is likely to mess up but not always in a particular direction, and the answer is to be anal about watching all the time.

monopoledance 5y ago

Tl;dr: Lots of houseplants die. The end. Anyway, since you are here: You may kill your plants with tap water. Plants evolved to get demineralized rainwater. The salts of tap water will build up in the soil, slowly poisoning the plant. Additionally the pot is also the plant’s potty: It disposes excess minerals and waste through the roots, and expects the rain to flush it away. It’s best to water your plants with demineralized water, but you can also use (old) boiled and cooled down water, which lost at least some CO2 and consequently fell out calcium. In any case, if you water your plant, do so thoroughly, until water comes out at the bottom. Let it collect for a few minutes and then dispose it. Do not let it reabsorb! This will help the plant getting rid of salts and also helps not getting the soil soaking wet. Btw. this is also why irrigation is a problem for food security. Using straight underground water for crops in hot regions will only work for a few years, until the soil is dead for good…. Edit: Oh yeah, and IIRC the snake plants leaf tips are crucial for growth. They may be hurt from handling in the store and will consequently not grow in length anymore. Not sure it has anything to do with watering at all. My snake plant got “store leaves”, which haven’t changed at all over the years, got brown just at the very end, and new leaves, which are almost double the length and totally healthy. Maybe a brown tip is just the normal display of a leaf without a head (cell). Fun fact: Did you know snake plants store “sun energy” at daylight, and then do the rest of photosynthesis at night? So they do not lose water due to evaporation as much, when opening their pores for gas exchange! Pretty cool, eh?!

Factorium 5y ago
Doesn't that also flush out any fertilizers added to the soil?
- monopoledance 5y ago
  Yes, but that's a good thing. You are much more likely to burn your plant with fertilizer, than starving it. If you think about the typical environment most plants adapted to, you will not have a year's worth of N2, P, ... supplied once a year, but a constant, very low exposure through rain and continuous organic decay/production processes in the soil and above. For the most part, plants rely on osmosis, the capillary effect and evaporation to transport nutrients. Salt levels, including fertilizer, modify the osmotic costs and limits.

zeteo 5y ago

I've read the part about roots several times and don't understand it. Is there some intermediate level of actionable advice between "water once a week" and this? If anyone can explain it to me in a way that makes sense to a programmer it would be much appreciated. I do have multi-year surviving house plants but worry about their roots. > This comes about by having the roots well distributed in free-draining soil so that water and oxygen can feed the plant. From this you can infer there might be a problem If water runs right through the pot, and/or you squeeze the pot at its base and it’s rock solid. If so, take the pot off and have a look. From this you can also infer that, repotting into a much larger pot will just leave the roots buried in a mound of cold, wet soil, far from any roots. You might also see that a root-bound plant might not even need to be repotted, or can be repotted back into the same pot.

richardatlarge 5y ago
For many indoor plants, soil acts as a porous environment for roots to hang out in, where there’s humidity and air. Too much soil act as nothing but a wet blanket, too root-bound and the roots are not held in soil at all, so are poorly fed. Water only to rehydrate the soil, not to keep roots chronically wet
adriand 5y ago
Honestly don't worry about it. If your plants are growing and seem healthy, they are fine. Just ensure your plants have a pot that is appropriate to their size. Off the top of my head and based on my current plants, I'd say a plant that's 1 to 2 feet tall needs a pot around 6 inches in diameter and maybe 8 inches tall. 2 to 3 feet, 10 inches and similar height. 4 to 5 feet, 12 inches and 12 to 16 inches tall. Past that, and you don't need any advice on plants.
lathyrus_long 5y ago
I also found that advice about as confusing as all the other consumer-targeted houseplant advice. If you've got some time to invest, then I believe you'll find that advice for professional growers makes a lot more sense, much more quantitative and backed by trials and chemical or biological mechanisms. I quite like: https://www.fs.usda.gov/treesearch/pubs/46345 https://www.fs.usda.gov/treesearch/pubs/46345 That's a guide to operating a nursery, developed by academics seeking to distill the scientific state of the art into something practically useful with basic equipment. Specifically as to judging how much to water, I go mostly by weight. Thoroughly wet the medium until water runs from the holes in the pot, and then don't water again until the weight drops below some fraction (e.g., 20%) of that maximum. You can use a scale, or judge by hand with practice. You can also wait until the plants show drought stress. For example, they might visibly wilt, or succulent leaves and herbaceous stems may go from turgid to limp. That's probably not optimal, but it's better than overwatering. Finally, you can also pot in media with very low water holding capacity, like a blend of normal potting mix and perlite. This makes it near-impossible to overwater, but the tradeoff is that frequent (e.g., every few days) watering then becomes mandatory.

yumraj 5y ago

Orchids are notoriously hard for us, we’ve managed to kill several of them. I guess mostly due to over watering.

curiousllama 5y ago
Orchids are notoriously hard in general, to be fair

adriand 5y ago

I have, and have had, numerous thriving houseplants. My largest plants right now are about five feet tall. I also have three orchids that do wonderfully, a selection of cacti, etc. I do still kill plants from time to time but it's rare. In any case, I don't really agree with much of the advice in this thread. In order, the most important things IMHO are: 1) Caring: you actually have to care about the plants. This requires that you notice how they are doing and if they aren't "happy", taking action to try and improve their environment. 2) Light: if the light is bad, you're screwed. People keep talking about overwatering but not providing plants with enough light is just as bad and probably worse. Plants indoor get far less light than they do outdoors. If you have a very sunny room, in most cases the only way plants will do poorly is by totally neglecting to water them. 3) Water: not particularly difficult. With most plants you only need to water when the soil is completely dry. What I would especially suggest you do if you are starting out with houseplants is to purchase plants that show, by virtue of their foliage drooping, if they don't have enough water. The leaves of a peace lily will droop. The leaves of devil's ivy will start looking floppy. I've noticed that my spider plant's leaves seem to become paler. Some plants (e.g. ones that look like palm trees) will lose their foliage, starting at the bottom. In any case, if you have a plant like this, it is visibly telling you it needs water, so it's not hard to comply. It can also serve as a sort of canary in the coal mine for your other plants. That's honestly about it. I repot the occasional plant, and sometimes I do a little light fertilizing. But if you have a plant that is doing poorly, my advice in almost all cases is simple: ensure it gets more light, and don't water it until it's totally dried out.

frazbin 5y ago

Biggest problem for indoor plants is lack of light. Get a cheap photometer and check. Eyes are terrible at judging light intensity.. if the plant never gets light sufficient for basic metabolism, it will die sooner or later. Bare minimum full shade is like 10000 lux.. indoor lighting often doesn't get above 1000.

onecommentman 5y ago
And the good news is 4 foot LED tube lights are cheap, inexpensive to run and easy to mount with just two-sided tape. It’s a simple DIY project to mount LED tubes on the underside of a table and put that table on top of another table…and you can grow whatever you like. Plants won’t just survive but actually thrive and flower. Doesn’t look half-bad either.

martyvis 5y ago

The Aussie national public broadcaster, the ABC, has the fantastic Gardening Australia show that has been going for 32 years (in its current format). It's not too pretentious and is full of great technical pragmatic tips from knowledgeable professional horticulturalists and experienced amateurs. You might like this series on indoor plants as we call houseplants. https://www.abc.net.au/gardening/the-great-indoors--containers-and-potting-mixes/12920438 https://www.abc.net.au/gardening/the-great-indoors--containe...

Scoundreller 5y ago

This fellow cuts through a lot of the bullshit on his blog/newsletter. https://www.gardenmyths.com/ https://www.gardenmyths.com/ Unfortunately, there’s often a lack of good evidence except from industrial agriculture.

tdrdt 5y ago

I think one of the biggest misconceptions about plants is: they only need water (and light). Yes plants need water, but they can't grow on water alone. They need all kinds of minerals that are in the soil. When those are gone the plant will die. When you repot plants you add fresh soil so you also add minerals. But when you don't repot you need to add those minerals once in a while. Tip for aquarium owners: a lot of plants benefit from the 'dirt' in dirty aquarium water. An also lesser known fact is that there is a huge symbiosis between bacteria, fungi and the roots. So in fact you also need to keep them alive.

crooked-v 5y ago
> Tip for aquarium owners: a lot of plants benefit from the 'dirt' in dirty aquarium water. There are some interesting-looking mini-aquaponics systems out there that could be useful for anyone who already knows how to take care of a fish tank.
lathyrus_long 5y ago
If you like aquaponics, then take a look at Goliad Farms. He raises greenhouses full of tropical fish, relying entirely on plants to remove ammonium from the water. And yeah, that root zone microbiome is complex, though somewhat different in containers than in nature. In soil-like potting mix, you're generally guaranteed to have nitrifying bacteria, so ammonium fertilizers are still generally safe to use. (Ammonium can easily become toxic to plants; but soil bacteria oxidize it to nitrate, which plants tolerate in higher concentrations.) Stuff like sulfur to amend soil pH doesn't necessarily work in containers though, since you don't necessarily get the bacteria that oxidize that to sulfuric acid. Nitrogen-fixing bacteria for legumes may also not be present unless deliberately inoculated. The plants would die without that microbiome in nature, but with human help it's not mandatory. Many hydroponic methods run with a root zone that's as sterile as possible, and the only major change required is to supply most (~90%) of the nitrogen as nitrate.

dvh 5y ago

My 2 huge plants (ficus benjamina, 15 years old, grown from 1 tiny branch, and aglaonema, ~40 years old and survived one freezing): https://pbs.twimg.com/media/FC7tsGGWEAkInx1?format=jpg https://pbs.twimg.com/media/FC7tsGGWEAkInx1?format=jpg

richardatlarge 5y ago
Nice plants!

TwoNineFive 5y ago

What's that you say? Off topic? Yea I agree, but... As a systems and network administrator I know that the vast majority of outages are human initiated. Maintenance gone bad. Simple mistakes such as unplugging the wrong cable. Stupid stuff. Sometimes thresholds such as disk usage or other resources get exceeded or a part just wears out and breaks, but usually it's us stupid humans fucking something up with our own hands where it would have been just fine if you had left it alone. So there's your servers are houseplants advice. Stop touching them. Stop doing stuff. Leave it alone. Of course that's impossible. We have to get new plants installed and have to find that equilibrium they like to thrive. But when you find it, leave them the fuck alone and don't break it.

timdaub 5y ago

The most bewildering tip I always see and often hear recited is that a plant likes it to be moved/rotated. Like wtf, which plant gets rotated in nature??? Generally, some people like to think they know better what the plant needs than itself. I went from being talked in to overcaring to the probable most careless approach. My plants get water when the soil is dry. That's it. Gladly, I also ended up stopping to interfere with e.g. how they grow and I've now noticed that they started to look "wild" and healthy. Done right, it's a beautiful display of nature.

sufiyan 5y ago
Something I learned to do is to only water the leaves (ie make them wet). And if the soil is very dry, to pour water directly to the roots. My reasoning being that rain unless it is heavy, doesn't actually reach the soil directly and then there is the matter of water coming out through the openings in the pot if there is too much of it. I don't know why this works for me.
- vladvasiliu 5y ago
  > only water the leaves Doesn't this get a lot of water on the ground? Or do you keep your plants in a dedicated area, where water wouldn't be much of a bother? In my case, the plants are in the living areas, on hardwood floors, where I usually walk. I'd hate to get my feet wet every time I walk next to them.
  - sufiyan 5y ago
    Yes you are right in that I have a dedicated place for them. You could try using water sprays instead.
tgb 5y ago
I assume rotating isn't for the health of the plant but for giving it a more symmetric and fuller appearance.
- 5y ago

nottorp 5y ago

> To get an even better answer, ask a better question: ‘I water my sansevieria (snake plant) about once a week, and it’s not in direct sun. I’ve had it for six months and it was nice when I got it. But now the tips are brown, what am I doing wrong?’ Hmm where have i seen that before... oh, here: http://www.catb.org/~esr/faqs/smart-questions.html http://www.catb.org/~esr/faqs/smart-questions.html

brodouevencode 5y ago
As I was reading this all I could think was that this should be popped up before any stackoverflow post is allowed to be submitted.

spaetzleesser 5y ago

When it comes to houseplants you just have to ask my mom and you will know everything that’s to be known. If there is a problem she needs maybe 10 seconds to take a look and give you the solution.