If you read the responses to folks requesting advice on how to care for plants that are native to the rain forests of the world there will almost always be one or more responses recommending not to water the plant very often. That would appear contrary to nature since in the rain forests of the world it rains daily for as long as 8 to 9 months each year. One of the plants that often receives this advice is the beautiful Peace Lily (Spathiphyllum) which according to science is frequently found living either in water or on the fringes of a pool of water. A common answer when someone asks why their plant won't "flower" is to suggest the plant is likely too wet and then to suggest the plant only be watered when the leaves droop. I've read the same advice for jungle cactus such as Epiphyllum and Zygocactus species. True, these don't often live in the wettest portions of the rain forest but they are only found in nature in a rain forest! I found an article recently suggesting orchids should never be misted because the water will destroy the flowers and rot the leaves? I wanted to write the author and ask if she had ever been to a rain forest in Panama, Costa Rica or Ecuador where orchids are in bloom all the time? How in the world would Ma Nature make it rain for 9 months and not get water on the flowers or leaves? I frequently read similar advice saying to keep these plants in low light when many of the most popular rain forest plants are constantly trying to climb a tree to reach brighter light. I'd like to understand the reason that advice is given as well. I read the same thing for species that are members of families such as Philodendron, Anthurium, Epipremnum (Pothos), Monstera and many others. I am currently working on a proposal to a garden magazine for an article on the care of popular plant species that originate in the rain forests of the world. I've written many articles on related subjects in the past but keep running into a puzzling question in conflict with nature in the advice often given. I can't figure out where some of that advice started or why it persists since it often doesn't work. So I can better address the reasons why growers offer such advice I'd really appreciate your feedback. Your assistance will be much appreciated.
I can't count the times I've been told that the biggest cause of houseplant death is overwatering. I suppose that could be true. Eh, I've always noticed people underwatering houseplants, then the overkill comes from letting them sit in drained water. My own sister uses the tried and tested method: she waits until the leaves wilt to water her African violets. So sad. The only plants I've lost to overwatering have been outside during hurricanes. I'm subtropic. Of course, even tropical rain forest plants can sometimes be killed by saturated soil that gets compacted and then the roots rot in standing water and you get that lovely hydrogen sulfide wafting by. Not sure what the answer is, but it probably is along the lines of "generalities are near useless."
I have no idea how these things get started, Steve, but here's my best guess - people are trying to give advise in sweeping generalities, so that what works for say, African Violets, will also work for a Philodendron. In terms of the Spathi, the plant itself is extremely adaptable. In my hikes and whatnot I have seen it growing in a very wide range of conditions, from riparian and fully root-submerged in standing water, right through to dry soils that would only get moisture filtering down from the canopy (and let me tell you, in the primary forest, that's not much even in a heavy rain!) Because Spathiphyllums can tolerate periods of dryness, it seems to have followed that they should when grown as houseplants. I'm willing to bet it has something to do with the composition of the soils that they're generally sold in, which are nowhere even close to the soils where they're found naturally.
Great comments. I have an idea where this idea originated but I want to read a bunch of responses before offering what I have observed. Regardless, it does seem strange that once a plant is removed from the rain forest it should no longer love water at least in the eyes of a "house plant" grower. Just yesterday I read a post recommending not to over water Monstera deliciosa which is a plant that lives right on the banks of streams. Lots of people certainly do pass along what they've been told even if it has no basis in nature or science. And Beth, you already know my belief regarding the soil! Should make an interesting article anyway. Thanks!
I'll also point out that I grow Dieffenbachias in full sun, which is against every shred of traditional ''indoor Dieffs'' wisdom out there. They love it.
Unlike the tropics, we have a winter, when tropical plants do not grow at all. This is when they don't need water, and watering can be bad for them. If they come through winter and start to grow again, then they need water.
This too is an unfounded idea that is commonly accepted by growers. I grow over 300 species of tropical plants in my atrium in Northwest Arkansas. Even though they do slow their growth in winter almost none go dormant and stop growing. The few plants I can think of that go into any form of dormancy are some of the Alocasia species as well as the occasional Amorphophallus species. It is true most of these plants don't produce their reproductive flowers and or inflorescences (groups of flowers) during the cool or cold months but they don't do that in nature either. Actually, my plants are kept cooler in the winter than they would in a home but they still grow and don't go dormant. This photo was taken in February of this year and you won't find any detectable "dormancy" in anything. The temperate inside the atrium the day this was taken was about 60 degrees F. During the winter I still water 3 days per week for 2 full minutes each day. Nature does slow down on the water in the winter of South America (which isn't like our winter) but the plants are still in a very humid environment. The humidity is the key to their getting water since many just absorb it through their roots which are for the most part exposed to the air since they grow as epiphytes (epi-FITS). But they still need the water. I know the answer to solving this but would very much like to hear why others believe what they have learned to accept before I make any comments. Part of what I would love to teach others is these "myths" are something growers made up, believe and pass along. If a grower treats a tropical plant as it grows in nature it will grow just like it does in nature. It strongly appears the plants in our homes slow their growth because we force them to slow down due to a lack of water and likely by providing reduced light rather than anything nature has imposed due to their being taken out of their natural hemispheres. If anyone were to visit a good botanical garden such as the Royal Botanic Garden Kew in London or the Missouri Botanical Garden in St. Louis during the winter the plants look largely the same minus some of the flowers. They don't slow their growth to any degree even though it is still winter outside the building and that is because the garden staff treats them just as if they were living in the rain forest. Still, the sun is much lower on the horizon in both London and in St. Louis but the plants just don't care. The answer lies in the soil as Beth hinted. Thanks for the input, this will make a great few paragraphs to approach in the article but there just isn't anything in science to back it up.
What Lorax says about the great diversity of growing conditions in the wild for plants known to be rain forest plants holds true for me in the subtropics of Florida. I've been on many botany hikes where we've found wetlands plants growing in xeric uplands, or plants that need a chill period to fruit or to germinate but somehow managed to grow in a warm mesic forest. Plants do adapt. Heaven knows we've all seen some granny with a decrepit Philodendron scandens with curling leaves and attenuated growth trailing over the patio door. It lives, but it hardly thrives. I can't dig up any clear references on it, but I heard long ago from a forester that the ubiquitous St. Augustine lawn grass in Florida is bred from a vigorous grower and seeder found in St Johns County (St Augustine, of course!). Since I was obliged to have a spot of lawn, I wanted the original subspecies. No can do, because some big turf conglomerate owns as much of it as could be found, and deemed it too easy to propagate. Much better to hybridize a thick turf grass that will spread with the right conditions, but won't reseed. You don't see St Augustine grass in wild places as you would Bahia and centipede grasses. Requires too much water for one. I doubt smaller nurseries are invested in giving us misinformation to promote further sales, but Big Agro sure is. Big Retail probably is. Heck, small retail sometimes is. I bought some Cymbopogon citratus at a grocers because it had the vestiges of roots at the swollen base of the stems. Rooted very easily for me, but people I referred to that store can't buy it with viable roots now because the proprietor knew what I was doing and cuts them off a couple of inches higher.
My dad loved St. Augustine grass! We grew it in Dallas and then I grew it in Florida when we lived in Miami. The stuff won't grow in Northwest Arkansas since it is too cold or I'd have it here for sure but you are certainly right about water! I'm still trying to figure out the best approach to explain why so many of these "old wife's tales" about tropical plants are just plain wrong but all this input is helping to build an outline for the article. I just spent an hour photographing my own "rain forest" and as I sat there I wondered why it is so easy to make these plants really grow and prosper but so difficult to get home growers to believe what I try to explain. I water "less" in the winter but I never stop watering and in most cases neither does Mother Nature. Once you "believe" something it is often very difficult to allow yourself to understand the people that taught you really knew very little about Mother Nature and the way she grows her plants. Please keep the comments coming, and thanks!
For those that still don't think tropical plants need water in the winter please take a look at some of our latest photos here: http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=58903
In northwest Arkansas, you're virtually in the subtropics anyway! So far south, that winter daylight isn't much shorter than summer daylight. Up here at 55°N, winter daylight lasts less than half the length of summer daylight, and if it is cloudy, light intensity even at noon is very low (sun 11.5° above the horizon). So even if plants are kept warm, they're still not growing much if at all, and don't need much water. Also worth bearing in mind that although tropical rainforest may have very high rainfall, it also very often has very sharp drainage, so plants don't stay in waterlogged soil after the rain.
Perhaps Michael. During the summer the sun sets at 9:00PM. Right now it is gone by 5:30PM so we've lost almost 5 hours of sunlight every day since June. Your observation about the rain forest is partially correct. There are many areas in Brazil and Ecuador where the plants stay fully submerged to almost fully submerged for months. Spathiphyllum is one of the species home growers always tell their friends not to water until the leaves droop and the plant is begging for a drink but in the forest it lives in water or on the edge of a bog all the time. I actually grow it in water and know quite a few tropical growers that do so as well! I read a post on one forum yesterday saying Philodendron don't like water and the very next post said they should only be grown in water. Neither is correct but if people have been given such advice by a "friend" they will follow it until the plant dies and then ask "why"??? The big thing that home growers don't want to hear is they should not use off the shelf potting soil unless they fix it first. The stuff is like mud and tropicals need drainage as you said. I've tried to explain many times the off the shelf soil must be amended with bark, Perlite, charcoal, finely sliced sphagnum moss, compost and other amendments. That is precisely what we did before we began to plant anything and the results are reasonably obvious. Other than plant them we do nothing other than water and a little fertilizer. Tropical plants are tropical and love water. It rains almost all the time in the tropics and when it isn't raining it is still humid. They just hate soggy soil. We grew our plants just like this in our living room for many years before I decided to build the atrium but all we did was amend the soil and keep them quite damp. I just wish I could get that across to all the fine folks that ask why their plants aren't doing well but ignore the advice. I don't make it up, I just learn it from the professionals that run the best botanical gardens in the country. I have never had a green thumb but I can follow good advice. The world is full of bad plant advice but people want to believe it. Just look at a few photos and decide for yourself if you should follow the "old wife's" or the advice of Mother Nature. http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=58903 Perhaps someday!
One point I'd like to make and that is that growing plants in containers does not yield the same results as growing them in the ground or in beds. Even the best draining conventional nursery pot can still keep many tender tropicals too wet to avoid rot. I've seen this firsthand in my own growing. Would that it were as simple as water plentifully; such an approach would have left me with very few Alocasias in my collection, and much fewer Anthuriums and Philodendrons as well. Many factors are involved in the survival of tropical rainforest plants, from the soil medium composition to soil microbiota, to associated or companion plants. Also, soil vs. air temperature and insolation or lack thereof are important as well. So it is not just a simple case of "old wive's tales", which often have a grain of fact at their core. You really need to know the year-round environment of a plant grown optimally in native habitat (i.e. the median of the growing range), information which is sadly lacking for most of the horticulturally desirable varieties and species. LariAnn Aroidia Research
I certainly can't argue with you. Still, we have several hundred large specimens (only a few Alocasia other than Alocasia odora) in the fast draining mixtures I mix individually for each plant and all are watered by the auto timer in the same way. I have them segregated in three zones one of which is wetter, one moderate and one a bit drier. Right now we're watering for 2 minutes three days a week but in the summer we water forup to 8 minutes every other day and on really hot days we water twice daily. The temperatures never drop below 55F and the humidity stays above 85% all the time. In fact, the humidity is so high we had to do several thousand dollars worth of wood repair and replacement just last month. As can be seen in the photos which were taken just days ago the plants don't appear to object. However, I understand that every grower needs to monitor their own plants for proper soil moisture. The part that concerns me is when growers begin to advise to rarely or not water at all in winter or wait until the plant "begs" for water by drooping its leaves. I read it all the time and it simply makes no sense. By the way, your Alocasia robusta cross loves it in there! Two fairly large leaves already and another on the way.
Photopro, i'm with you on the winter growth and that plants still carry on growing despite a cold snap, my Strelitzia havent had any new growth all summer but as soon as it has got cold in our unheated conservatory they have started putting up new branches, it was almost as though they were waiting for it. My Ficus Robusta Black prince which must be 7 feet tall now also has carried on growing despite the cold weather we have had here, it was -5 two nights ago and it must have been just above freezing in the conservatory but its happily growing away, my Delonix too just to name a few plants and trees that are only supposed to grow in a hot climate. Funnily enough my Passiflora seeds, Brugmansia and Stapelia seeds have all sprouted during this cold spell on the window sill of the conservatory. I constantly try to defy the so called traditional wisdom by growing plants that people tell me have no hope of surviving a UK climate, my citrus is doing very nicely thank you out in the garden and in their 3rd year too. This has been an interesting thread and given me much to mull over. Thanks Nath I forgot to mention that i too continue watering regularly in winter despite the colder climate.
Thanks Nath! I am hopeful the word is getting out that tropical species still grow during the winter and need to be treated differently than many have been taught. At least my personal email has begun to indicate that folks on other forums that I don't participate in have begun to come to some of the same realizations. Although we see the fastest growth in our Exotic Rainforest atrium during the summer I often sit in in there and am amazed how good it looks in the middle of winter. I think the plants do in fact appreciate being treated as if they were still in the forest. I hope you continue to see good growth!
I was really hoping for more input on this subject but it appears it is time to wrap this one up. Since most people don't really want to bother with ever watering their plants, many people go into a garden store and a very rich potting soil that stays soggy all the time. As a result you may eventually kill your plant. Many plant species can literally drown in mucky soil! For some unexplained reason many growers believe the rich soil makes a plant grow better! Typical "potting soils" just don't work for the vast majority of tropical plant species since most grow in trees, not in soggy soil. The roots of many tropical plants are designed to*collect rain water during the wet season and suffer through the dry season. But even in the dry season a specimen can collect enough water from the humidity around their exposed roots to survive. * Although house plant growers commonly believe tropical plants do not need water in winter that belief is simply a myth. Tropical plants live in very humid conditions and are capable of gathering water directly from the air even during the drier portions of the year when it doesn't rain on a daily basis. Dew and fog are very important contributors to the water available to a tropical rain forest plant species and homes don't have dew or fog! If we deny the plant the water they crave they only suffer and will never be able to display their natural beauty. In the temperate rain forest the amount of water available from the dew alone is estimated to be between three to five percent of the total annual precipitation! As a result, your tropical plants need water year round but it is wise to reduce the amount offered during the winter. We water every week of the year averaging four days a week in summer and three days per week in winter. As can be seen in the photos in this thread the plants love water. Despite the belief of far too many growers, growing tropical plants is much more than whether you should water once a week, every other week, or every other day! It is not just about the water content of the soil! The advice to water only once a week and keep the top two inches of the soil dry is not particularly good advice! Many aroids and other plant species grow well in very wet soil providing the soil is properly mixed! Instead it is about how fast the water flows through the soil, or the lack thereof. Lack of fast water flow causes a lack of oxygen, anerobic fermentation and saprophytes which turn into pathogens. Saprophytes are organisms including fungus or bacteria that grow on and draw nourishment from dead or decaying organic matter which often includes soggy wet soil. The pathogens attack the roots and cause them to rot so all of the advice to "slow down on the water" is really about how to control the pathogens. Fermentation and saprophytes often occur in muddy soil that will not not allow the roots to breathe but they don't necessarily occur in water which is why we can cause a plant that is about to die to grow new roots in clean water. As a result, it is necessary to use soil mixes that allow the roots to breathe and will not remain soggy. I've attempted in many threads to explain the necessity of mixing proper soil for plants but the advice is often ignored since it requires some "work" on the part of the plant's keeper. The reason plants rot is not the amount of water given to the plant, it is how long we force them to sit in muddy oxygen poor soil! These are rain forest plants and are literally drowned for months at a time! If you could visit a rain forest you would quickly learn the soil is composed of leaf litter, decaying wood, compost and the charcoal left behind when a part of the forest burns. If we'll just listen to Mother Nature we can all make our plants grow as they should in nature. That is precisely what I attempt to explain when I recommend mixing soil, not just buying a bag at the store. Over time we've developed a soil mixture for most of our aroid and tropical species. We use this mixture on the advice of the aroid keepers at the Missouri Botanical Garden in St. Louis. The goal of this mix is to allow the roots to freely find places to extend and grow without constantly finding wet places where they will rot. This mix will remain damp but drain quickly. Rather than using a rich, soggy soil and watering only once a week (or less), use a soil that holds moisture well but drains quickly. With the help of botanical garden researchers we've developed a soil mixture*for most of our specimens that works great. People who visit our artificial rain forest are often amazed at the size of many of our specimens which grow much faster and larger than they often do in a home. The exact mixture is not critical but we use roughly 40% potting mix combined with 20% high quality peat moss, 20% orchid potting media containing charcoal, hard wood and gravel), and the balance cypress mulch mixed, with 10% Perlite™ and finely shredded pieces of sphagnum moss. We often add extra charcoal such as aquarium charcoal or hardwood charcoal to help purify the soil and sometimes volcanic rock If you are concerned about your soil remaining wet just add more orchid mix, cypress mulch, Perlite and sphagnum moss. We grow many different species in this basic mixture and some of our specimens have reached their adult or near adult size and regularly produce a spathe and spadix (inflorescence). The goal of our mixture is to cause the water to flow through the soil quickly, remain slightly damp, but never soggy. The roots of our plants attach to the bark just as they do in nature*on the side of a tree. Most growers call a mix similar to the one we use a "jungle mix". Again, I welcome your input. We also openly invite anyone living or visiting in MidAmerica to visit our private botanical garden. There is never a charge. *
A potted plant is much like your lungs. When you pour water in the pot the air inside the soil is displaced so the old air inside leaves the pot. In effect it has "breathed out" just like your lungs. If the upper soil layer completely dries the "lungs" of the pot cannot work (develops "reverse asthma") and can no longer draw in another breath of fresh air. As a result the top layer of a potted plant's soil should not be allowed to dry. Once the soil dries out it creates a "blanket effect" which prevents the depleted oxygen in the soil from escaping and fresh air from replacing that which has already been used. Once the soil dries the moist layer below the dry upper few inches can no longer easily "breathe" in. In order to re-oxygenate the roots the often recommended dry layer must be kept from ever forming since it actually prevents the capillary effect of wet surface evaporation when damp soil is exposed to air. As a result the entirety of the soil needs to remain evenly damp so the roots of the plant can continue to draw in fresh oxygen. Otherwise, root rot is even more likely to begin.
Steve, as a late starter in the game I read your advice avidly, and your explanation of the top layer not being allowed dry out makes a lot of sense. We managed to kill two Alocasia cupreas and everyone said "don't water them in winter". Last winter a new one in the hothouse was watered only by the misting system, so the top layer (only) would have got watered. Now look at it! A final query: what about the plants that die down completely in winter, like some Calatheas, Amorphophallus, Costus and Alocasias and the Anchomanes difformis? Enough going on underground for them to need more water than the mister gives to the top couple of centimetres?
Alocasia cuprea is one of the most difficult of all species to keep alive so you are obviously doing it right now! Since Alocasia cuprea is from Borneo I suspect it grows in leaf litter. The species is found mostly on slopes and is it is not common. The habitat would appear to indicate a fast draining medium that is not overly wet but also one that doesn't dry out. As the quote beneath my signature always says "Listen to Mother Nature. Her advice is best!" it is very important to understand where a specimen originates in nature and then learn how Mother Nature grows the plant. Some species live almost totally in leaf litter. Amorphophallus is certainly one in many parts of its native habitat while in others a few species grow in a fairly heavy mud. The difference is those that live in the thick soil experience both an extreme wet season and an extreme dry season. As a result it is always best to try to learn how the plant is grown by nature. I always slow down on the water during winter but I never stop. We only water with an overhead misting system as well which makes the soil stay even from the top to the bottom of the pot. For those that don't have a misting system the old "garden bucket" with fine holes does much better than a glass of water just dumped into the pot! Misting on a regular basis is also highly advisable. I would suggest anyone that wishes to grow a new species go to some of the scientific sources and learn how it grows in the wild. Sources such as the Missouri Botanical Garden's TROPICOS have a page called "specimens" in the heading for each species. If you click that then go down the specimens list you'll often see a specimen number to the right of the page. If you then click that number you will frequently read a botanists description of the growing conditions for the plant. Other than that I always suggest doing some good homework on the species and find out where it grows in nature. Then I do a weather pattern search for the country or area to see what information I can dig out. Even in those countries that have a "wet" and "dry" season there may be high humidity year round! It doesn't take a lot of research to figure out how the plant does in nature. As for Amorphophallus, some species including Amorphophallus titanum need to be grown in extremely fast draining mixes but once the plant goes dormant should receive no water at all. I've found that many botanical gardens will freely share this information with an interested grower if asked. Just by asking I now have a list of more than a dozen botanical scientists and gardens that answer such questions on a regular basis. For Amorphophallus check the Berlin Botanical Garden. Although I will never consider myself an "expert" I am always glad to help any collector find good info by asking the real experts. Just ask it here or send a private note. Lots of growers love to keep "secrets" but I just love to see plants thrive. By the way, if the question pertains to a plant that isn't an aroid please drop me a note as well if posted here! I specialize and often don't read posts that don't pertain to the plants I enjoy learning about. I'm really glad you are having success with your A. cuprea!
It has been brought to my attention that some on this forum believe I am talking down to people when I recommend methods that differ from commonly held beliefs. I just hate to see the same questions asked again and again with responses that may not address the real problem the grower wishes to solve. It would at least appear if the methods always worked the questions would soon cease. I cannot believe an aroid grown in a pot in a home is any different from any other aroid. They all need the same treatment they would receive from Mother Nature which includes fast draining soil that needs to stay damp, humidity and good light. All can be provided in a home just like they are provided in my atrium. However, if any grower prefers to use another method please feel free. I just hate to see plants die of root rot and spend many hours every year trading information with many of the most successful growers, botanists and botanical gardens in the world. All the best advice I have ever received indicates these plants need consistently moist soil that drains very quickly. When you give them a good soil mix, water more frequently, and provide good light you see major growth along with inflorescences once the right season approaches. Still, the way you grow your plants is up to you so I am leaving this thread for others to complete. I wish you good growing and great success with your plants! Just listen to Mother Nature.........she knows more than any of us about her plants!
Keep up the good work Steve, There a a lot of us who are not experts at all. And will have more questions.
steve, i didn't find this particular thread condescending, merely passionate and informative. i have a few aroids myself and i find your threads very useful. that said, yes, some of your posts (on different threads) have a slightly patronizing tone. people might be more inclined to appreciate said posts if you wrote with more humility. anyhow, i've learned a lot from you and my aroids are all very thankful.
Thanks! I just try to explain things as science states and my contacts in the botany community have explained are correct but I'm now certain some take offense since that sometimes does not agree with commonly held belief. For the most part I'm now trying to keep my posts strictly related to aroid subjects so I can verify information with the real experts before I begin to type. I do appreciate your input.
