I don't know how to advise you exactly when you are growing it as a houseplant. I grow it both planted in the yard, and in water gardens/ponds and have never really just kept one in a container of soil longterm. The ones in the ponds, I almost never repot. They seem to manage themselves just fine year after year.

It is my personal opinion that they don't care about being potbound. Colocasias are spreading plants in general, some spread more than others, by aboveground stolons (like Nancy's Revenge, escuelenta/Green Goddess, Chicago Harlequin, fontanessii, and Yellow Splash), while others spread more slowly underground (like Black Magic, Black Marble, Elepaio/Milky Way)

There is a form of Black Magic called Black Runner that spreads by stolons.

If its been in the same container for 2 years, I would say, go on and repot it now, some fresh soil and a boost of fertilizer would probably do it a lot of good.

Okay, this thread suddenly appeared..Is that odd or what?
Thanks Bihai..I'll repot as soon as possible..Do 'BM colocasia' like moist or soils that dry between watering?
I'm afraid to pot, add extra soil, then drown..My other Colo, and Alo, kept in the upstairs bathroom get a lot more humidity than the BM..but they are sitting adjacent a second floor, west, unobstructed window..They're summered outdoors..I'm confused as to water/fertilizer..Since they're confined to pots, would they need more or less water/fert?
Does anyone here grow Alos or Colos in pots? If so, how do you keep yours going? Thanks. Toni

When it comes to Colocasias, I've often heard it said "more water, more fertilizer, more bigger leaves." Warm temperatures figure in there, too, so I'd give it a bit more root room and be patient for now. Clearly you're doing something right!

Here is a link that might be useful: my website

Toni, I'd love to see a pic of it. Is it on your website?

Shanika

SHANIKA...I'm sooo happy seeing you here..where have you been??? Are you here to stay??? It's been a long time since you've posted..Welcome back..
An older pic (Colo) may be on my site..probably around the time I bought it, or after repotting..I still haven't figured how to dl pics from desktop or camera to Flicker..LOL..I wish Yahoo was around, it was sooo easy dl'ing pics..so any pics on my site are at least 2 yrs old..it's time to update, but can't figure it out..I've even considered starting a Photo Bucket account, but would have to figure that out too..LOL.
How have you been? I hope you're here to stay..We miss you..

Bihai,...thanks so much..Though Fl is having problems, I'd switch places with you anytime..(S)
Seriously speaking, I feel terrible about all that's happening there..Heat, lack of rain, and the ban on citrus..
I don't know what nurserypeople specializing in citrus are doing to make a living..It's sad..I know two women in Fl who sell citrus. (citrus trees are their bread and butter) It's awful the government kept the ban on so long..

Oh girl, I'm afriad to try growing my Colocasia in water..LOL..I have two Colocasias and one Alocasia..Are all Colocasias and Alocasias bog plants?
They are so pretty, quite interesting, but what happens with mine, for every two new leaves an older leaf dies..Could this be happening because of space or not enough water? Or improper fertilizers?
Which stakes work best? I have old fertilizer sticks, (3-4 yrs old) bought as a last summer feeding, but never got around to using them..They're All Purpose..I don't know if they're good anymore, (I just posted a thread about old fertilizers) but don't care for sticks..IMO, sticks only work on the area they're inserted, so only one part of the soil actually gets fertilized..They also sell flowering, Citrus and acid loving sticks.. One time I inserted a Citrus stake in a citrus plant..the darn plant died!! I don't know if the stake was too strong considering the citrus was in a 10" pot, but it died..Prior the stake the citrus was doing fine, which is one reason I decided to start their first summer feeding..
It's amazing Colos are labeled weeds in Fl..LOL..you guys have the nicest 'weeds.' So nice, ppl up north pay dearly for your bothersome weeds..LOL..
Okay, I'll start watering more, add a diluted fertilizer, and repot Black Magic in a larger home..The problem growing them here is during winter they're stuck indoors..My other Colo and Alo are in 5-6" pots..it's been a while since checking roots, but if they're overpotted, and kept wet, I fear they'll rot and/or attract insects. It's one thing growing plants outdoors year round, in fresh, humid air, another in stuffy, air, low-light homes. Not to mention short summers. One Colo, called striped, was purchased, I think last summer..possibly 2006..it has a total of 3 leaves, look sad..nowhere as green as it should be, and its center stripe has faded. The Alo Amazonica have two leaves..it does great in summer, outdoors, but once in the house, it goes dormant, which is normal, but loses a couple leaves..Still, I can't complain..this is the first Alo I've had more than 2-3 yrs..
Thanks for the help...Now if I could figure how to post pics here, and Flicker, will help when I have a question..Thanks to everyone who have offered suggestions..Toni

I think I had a colocasia black magic in my pond to a couple of years. I could not figure out how to overwinter it and I am sure it is dead now. It is still in a pot in the bottom of my pond until spring cleaning happens when the water temp=55
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Toots your pond is beautiful! I see Koi swimming around..I never understood if fish were kept in a pond year round or brought indoors..what do you do with your fish?
I remember reading an article about, maybe Goldfish, being kept in water during winter..and how pond ices up, yet fish survive..they also mentioned fish lay eggs..What do you do?
Are you saying, somewhere in the bottom, a Colocasia is floating around..LOL..Since you're in Wi, do you think any part is alive?
Even the hardiest, what are they called, Elephant Ears, need to be dug up and placed in a cool, but frost-free area during winter..Are they related to Alo/Col? The type leaaves grow huge, 2-3' long or longer..What about Taro? Does anyone know if it's related to Colos and Alos? Toni
PS..Toots, once again your pond is gorgeous..Isn't that a Black Magic growing outside the pond? Sure looks like one.

My that is an absolutely beautiful pond!
Hopefulauthor, I don't want to sound like a know it all, but you have asked so many questions about 'elephant ears' I think I can help you understand about them a little more.

'Elephant ears' are Aroids. They are in the same general family with Philodendrons, Anthuriums, syngoniums, caladiums, etc.

"Taro" are 'elephant ears'. Taro is a sort of a general term used for the edible tubers of elephant ears. Taro is a very important food crop worldwide. Its most commonly known as "poi" in Hawaii. Its also called dasheen and eddo. The type of taro most commonly used as a food source is COLOCASIA.

In the ornamental plant trade and industry, there are really only three types that are used on a widespread basis in the USA:
Colocasia, Xanthosoma, and Alocasia

Of these three types, Colocasia and Xanthosoma are widely grown in water. Alocasia are more terrestrial. There are a couple of alocasias that will tolerate being grown in very wet conditions like standing water, many will not and will simply rot.

Here is a series of photos of some of the plants I grow. There are a lot of them, I apologize, but I hope you will find them interesting and helpful. Almost all of these grow in my yard. They go dormant in winter whether they grow in the ground or in water, and come back every year. A very few of these I have to keep in my greenhouse, they would not make it outside here. You may see some here you might want to try sometime. I will split it into 3 separate posts.

First, COLOCASIAS:

This is a very small colocasia that I use as a ground cover. Its called Colocasia Fallax. It will grow in water or in the ground. It spreads very readily by overground stolons. It rarely gets over about a foot tall.
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This is a very large growing Colocasia cultivar called Nancy's Revenge. I grow this both in tubs filled with water and in the ground. It also spreads quickly and rapidly by overground stolons
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This is a relatively new colocasia to the plant trade, but it is actually one of the oldest forms in cultivation, having been one of the major varieties grown for decades in Hawaii as a food crop. This is a variegated colocasia called "Milky Way". The old Hawaiian name for it is "Elepaio". This type loves water and I grow it in water, and also in some of my flowerbeds in the ground.

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This is another variegated colocasia called "Yellow Splash". This variety is very beautiful, but the variegation can be a bit unstable. If you give it too much fertilizer, it will revert to all green. I grow this one mainly separate from all the others in its own tubs of water so that the can be grown "hard" (without fertilizer) to keep their variegation

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Here is one that is very readily available, this has been in the trade a long long time. Colocasia antiquorum "Illustris" (also known as "Imperial Taro"). I have these in many different places in my yard. The ones in this photo grow in a natural bog which alternates between being dry in periods of no rain and wet when we get adequate rain. These plants are about 5 feet tall with leaves that measure 12+ inches wide. The all green colocasia to the right is a large growing variety called colocasia "Ruffles".
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This is a "mixed" photo. The green ear is a Xanthosoma called "Lime Zinger" planted with Colocasia "Black Magic" for maximum contrast. These grow beside a small inground pond in the back yard. The smaller ear to the far left is Alocasia Culculatta. The COlocasia "in the distance" to the far right is Colocasia fontanessii, another definite water lover.
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This is a tub garden I have that has 3 different contrasting plants growing in it. The dark ear is Colocasia "Black Marble", then there is Colocasia "Yellow Splash" and Xanthosoma "Lime Zinger"
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And this is one of the newest colocasias on the market, it is called Colocasia "Tea Cups". The leaves are cpuued and point up, and hold water like a cup. This is a PARTICULARLY AQUATIC colocasia and loves water. I only grow it in water. It can get 6-7 feet tall.
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Alocasias are probably the most diverse group of the 'elephant ears'. There are thin leaved types, thick leaved types, velvet leaves types, huge growers, root hardy ones and ones that will go dormant and/or croak if they get too much chilling below 40F.

I have many different alocasias in my plant collection, these are a few I grow, first ones that I grow outside in the ground or pond and second ones that I have to keep mainly in the greenhouse. The second variety do make excellent houseplants in many cases as they tolerate some lower light conditions and even like drier soil conditions and will rot with overwatering, but, at the same time, they like high humidity in the air.

OUTDOOR alocasias:
Alocasia plumbea. This is a very large growing alocasia that has a metallic sheen to the leaves, which are very dark. It has a few other names in the trade: Alocasia plumbea nigra, Alocasia "Metallica", and Alocasia indica are a few synonyms. This plant does NOT grow well in standing water.
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This is an extremely hardy type of Alocasia that has the bonus of being variegated. When I got it, it was called "ALocasia aurea". Since then, it was called for a bit "Alocasia odora yellow variegated" and now it is believed to actually be Variegated Alocasia gagnea. NO STANDING WATER.
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There are also large growing Alocasia that are known as "trunk formers". One of these is ALocasia portodora, which is a hybrid of A. odora x A. portea. These are really very hardy and can get huge. This one grows in the flowerbed by my swimming pool. I have some in other locations as well.
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One of the most sought after alocasias in the trade is this one: Alocasia macrorhizza albo-variegata. It has been around for a long while, but seems to be rare a lot of the time, and is always expensive. This is one of the only alocasias I know of that can be grown in standing water. It can attain heights of 5-6 feet and is stunning when it gets very large.
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I only got this alocasia last year, its one of the newer types with unusual leaf shapes (like the batwing etc) This one is called Alocasia "Stingray". Its pretty cool. I grow this in the greenhouse.
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Two other plants that are strictly greenhouse plants for me are these:
Alocasia frydek "white variegated form", which is one of the "velvet leaved" alocasias...you can not keep this too wet or it may rot
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and Alocasia cuprea, which is a very very shiny leaved plant, the opposite of the velvet leaved type. But same applies: not too wet, or it may rot
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Another velvet leaved alocasia that many people grow in a terrarium is this one: ALo. "Black Velvet":
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The Xanthosomas are definite water lovers and almost all can be grown in standing water. The two exceptions I have found are Mickey Mouse and the variegated form of saggitifolia.

Xanthosoma saggitifolia, like Colocasia escuelenta, is considered a noxious weed here in Florida. The leaves of these plants get absolutely HUGE when the plant is grown in water, and will even get really big just grown in the ground by a sprinkler head or by the overflow pipe of an air conditioner.

This is a photo of my daughter Ariel that I took a few years ago, she was 10. The leaf she has is from one of the Xanthos that I have growing in a flowerbed out by my swimming pool
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This is the variegated form of the same plant. It doesn't get huge like the all green type, but its a cool plant and hardy, comes back every year. It likes damp soil, but not growing directly in water.
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This is a very old species of Xanthosoma that has been cultivated as a food crop. It is called Xanthosoma violacea, and its even older name is "Blue Tannia". The leaves are deep green and the stems are black with a blue tinge. This will get absolutely HUGE if given a lot of water, can can be grown in water or in a wet place in the garden. The specimen here is actually sitting in a sealed pot full of water.
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And of course, this is almost every one's favorite Xanthosoma: X. albo-marginata "Mickey Mouse". This plant likes water, but NOT standing water.
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Beautiful, gorgeous pond tootswisc!

Bihai, thanks for posting all those photos! I know it takes time, and I for one (plus many others I'm sure) fully appreciate it. I see some of those elephant ears for sale up here, but I don't think many people are successful, unless they've been able to create a sheltered microclimate for them. Our warm growing season is only the 3 months, and we get such huge winds from time to time, those pretty leaves would be destroyed. I do like to look at them and wish tho'. ~kioni~