I got some EE bulbs and some large stalks with just a slice of bulb and lots of roots on it at PG today. What are the chances of the slices with roots of growing back next year or should I keep them growing in pots this winter?
Thanks for the help.
Tropicals: Elephant Ear bulbs
I got some EE bulbs and some large stalks with just a slice of bulb and lots of roots on it at PG today. What are the chances of the slices with roots of growing back next year or should I keep them growing in pots this winter?
Hey leaflady,Root here,if you are new toEE'sI have tons,My problem is not getting them to grow,its what to do with all of them ,what type are they?I brought16 in yesterday,some with bulbs the size of footballs,I love them inside it adds a tropical feel to the livingroom.Root
Hey, Root, you aren't very far from me. We live near the State Fair town of Sedalia if you are familiar with MO. Just go down Highway 50 east and you run right thru it. Or go east on I-70 to Highway 65, turn south and drive thru it that way. The 2 highways(50 & 65)intersect just a few blocks from the fair grounds. We live about 13 miles NW of town.
I have no idea which EE I got. The stalks are leafless at this point. I'll stick these in soil and see what we get. There are so many pretty ones. I am VERY new to EEs but I do know I like varigated plants. They have some in the greenhouses that have white veining thru the bright green leaves. They are striking looking. Remind me of Christmas for some reason.
Do you think the slices with roots will grow? I'll likely try no matter what but would like to know which way they are likely to go. The intact bulbs I got are baseball size. I think there are about 4 of them. I think there are 4 rooted slices.
are they caladiums?Sounds like calocasia ,I have one that I believe is called Normas Revenge,I believe that they like ponds,it has the nice cream in its viens on a light green leaf,I do think the other is caladium,at least they are the ones that make me think of xmas,Root
Leaflady,I know where you are,I can have rootfatale drop off some EEs n her spring trip to the lake,Whats' with that peanutburger?Did you look at data base to see what you have?I am having a hard time understanding what you mean by slices?
Hi, Root. I really don't think I have ever eaten a peanut burger at Wheel Inn even tho I have lived here since childhood. Somehow it just doesn't sound good to me. I think they are called goober burgers.
When I say slices, I mean that when the stalk was removed from the tuber they left a piece of the tuber about a half inch thick with lots of roots on it attached to the stalk. I have removed the stalk from these 1/2" thick slices.
I would love to have some of whatever you want to get rid of. Can I offer some canna, day lilies or Magic lilies in return? I have dozens of Pretoria that Powell Gardens pitched. Have you been to PG? We do volunteer work there.
We gotta talk,Wow Powell,what a place,everyone should see it,Still haven't made the butterfly show,it's about 50 miles from here an seems only time in that direction is heading to the lake,And I must say Boiled peanuts are my favorite treat! I have never tried the goober burger,
I guess you have colocasia's if your bulb is big as a softball,Taro for us common namers,The leaves turn down,about 3ft tall,I will give you some alocasisia,it is a form with upright leaves that goes to 6ft,only have about 20 in the livingroom,I think I sure could spare a few for some Powell Garden leftovers,You are so lucky to be part of that!
Root MD, you're thinking of Nancy's Revenge (Colocasia nancyana). Yours must be young if it has just white veining. Their trademark is the white midrib that expands along the veins and broadens in the middle to a large sunburst pattern on adults. They are from the caribbean, not SE Asia, as most of our garden Colocasias are. If you put it in water, you will have rotted mush before long. Use a very well drained loamy soil and water sparingly. The recipe I've heard recommended is equal amounts of perlite, professional potting mix, peat and bark. Still, make sure you have a good fungicidal soil treatment on hand.
Leaflady, if the surface of the broken part of the corm has dried and it has plenty of roots, yes, plant it and you will get plants from it (eventually, though it could take months). I'm not sure EE bulbs would survive a winter outside in 6a whether broken or not. But, I'd at least pot the broken one and bring it inside. Give it normal warmth and fertilizer and water until ... well ... until a coulple of weeks ago. At this point, I'd say treat it well for a couple of weeks to get it established, then stop fertilizing and cut back on watering (water only when the soil is dry to 1"). You can put it in a cool, but not freezing, place if you need the space. It can be in the dark, since it will be underground and dormant. Then, six weeks before your last frost, bring it back to a warm, well lit place, start fertilizing regularly and keeping the soil moist. This way you could have them out of the ground early. Corms planted outside can wait until June to sprout.
thanks RIK ,the name has been bugging me,DW brings things home and its my job to keep them alive,I though corms were from caladiums?Gonna have to get in habit of not going by what momma tells me,You have some great info,thanks for helping me out.
Anytime, Root MD. I wish I had a DW that would spontaneously bring me a well established young Nancy. They are pretty sought-after. They were only introduced at an Aroid conference in Miami two years ago, and were the star of the show, and have been since then (a mini-history is in the catalog of plantdelights.com under Colocasia). A tiny pup online still goes for $20 to $25+, and I doubt you would ever be able to get an adult away from anybody.
I thought a little more about that soil mix. Personally, if there were plenty of peat/sphagnum moss in the potting mix, I'd skip adding more peat. The plant might also benefit from the addition of a half measure of sand (sanitized - available at any hardware store). Good drainage is important. Before I understood this, I lost quite a few of them by keeping their soil moist, like I did my other Colocasias. Nancys are vulnerable to bacteria and fungi that can grow in constantly moist soil. But, it sounds like yours is doing fine -- if it ain't broke, don't fix it. The one warning sign to watch for is if a new leaf, once it reaches full size, is smaller than the preceding leaf. That means that the root system is unhealthy and is dying back instead of expanding to support larger leaves.
Caladiums are closely related to Elephant Ears, though I think they make a more compact bulb-like thing, so corm may be the wrong word for every elephant ear. Elephant ear corms/roots are formed in different ways by different plants -- plants we call elephant ears are spread over at least three genera (Alocasia, Colocasia, Xanthosoma) with some exceptional ones in others. There are examples of the same species forming their fat root in two or three different ways: it can be a swelling, like a potato right at the base of the plant, or it can be the stalk that is created as the older leaves die. The stalk either sinks into boggy ground or the plant grows a little sideways so the stem lays into the ground, grows roots and develops that way. To me, the first way sounds like a tuber and the second way sounds like a rhizome (formed like iris rhizomes). I don't know how a botanist or hortaculturist would respond to this, but I think you can make an argument for calling it anything you want.
But, it seems to me that the gods of horticulture don't care much about this plant family. It can take years and years before a botanical name is assigned to a species that has become very commonly recognized and available at your local nursery: Alocasia "Elaine" just became A. reginae; A. "Black Velvet" just became A. reginula and A. "Green Shield" is now A. clypeolata (the last one is tough -- I think I got it right), and I'm pretty sure that Colocasia "Black Magic" still has no botanical name besides C. esculenta, which is a catch-all for almost any big Colocasia. So, getting them to define new subspecies based on the fact that one species has several ways to form its starchy roots is a long shot.
Thanks for the compliment. If you ever have a problem or a question (or a pup from your Nancy that you'd like to trade!), please feel free to email me.
elephant ear bulbs,WHICH end is up? I need help!! Oklahoma zone,When is the best time to plant? Thanks
If you have large bulbs for big green elephant ears, they are usually Colocasia esculenta, though recently one that has naturalized in Florida (Xanthosoma sagittifolia, often written 'sagittifolium') has come on the market and is becoming almost as common. They aren't given a different name on their packing, so you can only tell by the picture, if there is one. C. esculenta has heart-shaped leaves with relatively small top lobes and a smooth, matte surface. X. sagittifolia has shield-shaped leaves, with angular top lobes that point outwards rather than straight up (like bat's ears rather than cat's ears, if that helps). The first young leaves won't show the characteristic shape, but you should see it by the fourth leaf. The veins are more distinct, often lighter than the rest of the leaf and the surface has a slight patina, though I wouldn't call it glossy.
The bulb, or tuber, of the Xanthosoma tends to be bullet-shaped, while the Colocasia will be oblong or round, though both can be harvested at an age and in a way that they are virtually round. Growers seem to aim for a round shape. Maybe round bulbs are better for packing and transport.
In either case, you should notice concentric rings around the bulb. Those are where there were once leaves. The spot where the rings get smaller is the 'eye' of the plant and will be where the sprout forms (smaller sprouts may form on the sides of a large bulb). The opposite end may be smooth or may show some signs of fibrous roots, though most have been polished off and the bulb waxed to maintain internal moisture. Also towards the opposite the eye, you might notice small circles or dots on the sides. Those are where the basal roots were pruned off. They'll regrow in the same vicinity.
You can plant dormant elephant ear bulbs outside once the ground temperature is consistently above 60 degrees. That is still cool for them, but they may start growing slowly. When grown outside, they are notorious late starters and may not begin their famous rapid growth until the heat of June. If you want to speed this up, you can pot them indoors up to two months before you put them out.
Start by keeping them warm and slightly moist -- watering only when the surface is dry. Continue this as it sprouts and puts up its first leaf. You can water more frequently and begin fertilizing regularly after the second or third leaf starts to unfurl. Fertilizing is to give a boost to growth that is already underway and should be absorbed by an established root system; it can do more harm than good to the tender first roots.
You can get a significant jump on the season by starting your EEs this way, and, by June, the leaves can be several times the size of those that were planted outside.
Oh yeah, since you are in Oklahoma, remember to keep them well watered once you plant them outside. Colocasias in particular need consistently moist soil. The Xanthosomas can be a little more tolerant of dry spells if they are gradually acclimatized to them.
This message was edited Monday, Apr 28th 12:45 AM
Does anyone know what to put on the EE leaves to keep then from getting eaten? Mine are huge but are getting eaten by something. I have turned the leaves over and find nothing that could be having breakfast, lunch and dinner on them. Please help me.
Can you show a picture or describe the damage in detail? Are these neat chunks bitten out, matter nibbled away, leaving a network of dry veins, celular damage that leaves holes that look like they've rotted, cellular damage that leaves patches of the leaf dead but intact (like a thin, brown piece of celophane stretched across the hole), speckled, deformed, spotted with lighter color, burnt-looking, patches of pin-hole looking dots that eventually kill the leaf ... ? Many things can attack elephant ears and each one can look different. Not that I can say definitively what it is without close-up pictures (or personal inspection).
The most common three culprits are spider mites, slugs and certain caterpillars. Spider mites you will see as tiny, almost microscopic black dots on the underside of the leaves, usually making a barely visible web near the veins. Slugs can leave holes that look like they've rotted or dried out, depending on your humidity. Caterpillars usually munch evenly, unless you have a nest of babies, which could be taking tiny bites and leaving the veins. Best time to look for slugs is night with a flashlight. The best time to look for caterpillars is dawn/very early morning. Spider mites should be there all the time, especially if the weather is dry.
There are solutions for each, depending on what you have, and depending on the kind of elephant ear you have.
Hello Im VERY VERY new to all this gardening stuff
I need help please!
I am very eager to work on my garden but before i go any further I thought I should get some advice from other gardeners.
Im looking to have a rock garden with EE's and caladiums with a fountain on one side of the garden ( the left side is 14x4 & the right side is 15x9ft) is it possible to have these plants in a garden of this size with rock?
should i lay mulch down before I put the rock down (a sales person said to do this but im not sure?)
Should it be a certain type of rock (I was thinking of going to the stream beds to pick and choose what I want ,is this a bad idea)?
I have tilled where I am wanting to put my small lil gardens which is on both sides of my front porch the sun shines about half the day (missouri temp's) however there is a lil shade due to the big trees in my yard
I have bought two grapefruit size elephant ears which I would like to plant one on each side of my porch, Im not sure if I need to buy more EE's, also I have bought Caladiums Aaron(7 in the package x 2 pkges) also 2 pkge of the assorted caladiums.
It says on the pkge that March is the time to plant these beauties? Is this a good time or should i wait until the end of March?
Maybe it will be warmer.
Should i try to grow them inside my house and then transplant to the outdoors?
Other than tilling the ground is there anything else i should add to the dirt or plants before or after i plant them?
How far apart should I plant each buld?
Would it be a bad idea to add a few other plants in the same garden as these are in?
I love the smell of lavender and babys breathe how are these plants normally grow? I would like to add them somewhere but not in my green garden
How do i keep them alive and how long is the life of these types of plants, can I dig them up during the fall and winter months to keep them inside and alive?
Well.....I think thats all the questions i have for the evening
I am very new to all this and have not anyone that I can ask for help because no one I know has a garden (of any kind)So any advice will be greatly appreciated
I look forward to reading everyones opinions and advice
Have a nice day
Rock gardens are generally planned for alpine(cool climate, need little attention) or desert plants. Both require very good drainage, tolerate poor soil and do not require deeply tilled soil. Many traditional rock garden plants will grow in rock crevices or on the surface of rocky/sandy soil, putting down roots where they find a little moisture.
Elephant ears are tropical. They require rich, deep, loose soil with good drainage, and they can’t tolerate the cold and are not drought tolerant. At least two species are now commonly sold as green elephant ears: Colocasia esculenta and Xanthosoma sagittifolium. They are easy to tell apart. Colocasia esculenta has peltate leaves. That is, the stem attaches to the back of the leaf and not at the edge of the leaf. Xanthosoma sagittifolium has sagittate leaves – they are somewhat arrowhead-shaped. The tip of the leaf and the two upper lobes reach distinct points, while the upper lobes of Colocasia esculenta are more rounded. Between the two upper lobes, the edge of the leaf of Xanthosoma sagittifolium is also cut all the way to the stem.
The two plants have different growing habits and ultimate sizes. The Colocasia will grow quickly and can easily reach six or more feet in one season with leaves three or more feet long. As new leaves come, the earlier stems arch lower giving the plant a spreading form. I have not grown Xanthosoma sagittifolium from a large bulb before, so it may also quickly put out large growth, since it has a good base, but it generally reaches larger sizes more slowly. It can eventually grow much larger than Colocasia esculenta. I have heard of them growing leaves ten feet long and five feet wide (but not in Missouri).
Xanthosoma sagittifolium can also form a trunk (though it is technically an upright extension of the rhizome). It takes also pups, or puts up small offshoots, more slowly and less readily than the Colocasia.
Both will freeze in cold winters. With very good drainage and a deep, dry mulch, they will come back the next year in zone 7 (where winter temperatures rarely go below 10 degrees). In colder areas, the bulbs need to be taken up in the fall as soon as the foliage dies (or sooner if you want to cut the foliage back and take it up as soon as there is any sign of leaf damage from the cold). They should be stored cool (not cold) and dry and planted again in the spring.
They can be slow to start. You can get a significant jump on the warm season growth by planting them indoors six to eight weeks before planting them in your yard after the soil has warmed up. Starting elephant ears indoors is only tricky in one way: If they do not get good drainage and the soil stays too moist, they can rot. You can avoid the risk of rot by using a sterile medium, like seed starting mix and insuring especially good drainage by using half sand and/or perlite. If seed starting mix is hard to find, as it is around here, you can use sphagnum moss with a little more sand or perlite. I would also recommend a clay pot. Water the bulb well when you plant it. If using sphagnum moss, it may be necessary to let it stand in a dish of water for a few hours to make sure it absorbs the water. Do this only once. Don’t let it stand in water after the initial watering. After that, water only when the top of the soil or just under the soil is dry to the touch.
They should be ready to impress the neighbors when you plant them outside.
Elephant ears respond well to fertilizing. If you are preparing the beds now, you can use a lot of manure because there should be enough time for it to compost well before planting time. Manure bought in bags is usually pretty well composted already. If you are getting manure straight from the animal that produced it (remember, grass- and hay-eaters only), then it will need more time to compost or it will burn the roots.
Elephant ears can do well in sun or partial shade. Colocasia esculenta tolerates shade better, and can be scorched by too much sun unless it gets plenty of water. Xanthosoma sagittifolium has a more leathery leaf and loses moisture less quickly, so it tolerates full sun better.
Most of the above will work well for Caladiums. They are traditionally used in shade, but they will often perform well in sun if given enough water, but remember their need for good drainage – their bulbs can be prone to rotting.
If you are thinking of decorating your garden with rocks, there’s nothing wrong with collecting them yourself. However, there are a few exceptions. Rocks that have been on roadsides for a long time may have collected deposits from car exhaust. It helps to soak them in soapy water. It is also good to soak them in water with a splash of chlorine bleach, although that can damage any color from moss, algae or lichen. Chlorine and soap together can produce unhealthy compounds. If you search the label of your bottle of dish liquid you may find a tiny warning about this. Hose the rocks off well and/or soak them in clean water before putting them in the garden. If using rocks or shells from the seashore or another salty environment, soak them for a long time in several changes of water to get rid of the salt. River rocks are fine unless you suspect the river of being polluted, in which case use both of the approaches mentioned above to wash away and soak out pollutants as much as possible.
I hope this is useful. Post again if I missed anything or if you have more questions.
WOW thank you so much I greatly appreciate the advice
Heck Im not real sure if have good drainage or not :) When it rains the soon to be garden site stays wet for several days is this good,bad or ?
One of the reasons i was going to do the rock garden is because I was thinking it wouldnt be to much work for my schedule, which is what i need exspecially since this is going to be my first garden and also my girls dont leave much time for gardening and ofcourse I really like rock gardens
Can you direct me to the type of plants that would do good in my rock garden , Im leaning towards green plants for this idea maybe a hint of another color but not to much what do you suggest?
I look forward to hearing your advice
Thank you all so much
WOOSH...............Im glad i subscribed to this site before I really got in over my head :)
I'm not a good person to ask about rock gardens. I can answer questions about foliage plants, but most of the foliage I grow is annual and/or tropical.
As for evaluating your garden's drainage, dig a hole 12-18 inches deep and fill it with water. If there is still water standing in it the next day, then you have a drainage problem and need to work on your soil. A raised bed is a good way to improve drainage. Stack rocks or use landscape timbers to make a low wall around your garden and fill it with well draining soil. Mix in extra bark, sand, perlite; rock-garden people might suggest adding gravel or river stones. You'd have to ask someone more experienced with that.
You'll need to make more observations about how much sun your garden area gets -- how long and during what times of day. That will help you with your choice of plants.
Elephant ears are definitely not traditional rock-garden plants. You might want to choose a separate spot for them or grow them in containers (the larger the container, the larger the plants that will grow).
Thanks for all the advice, I'm taking notes. I bought my first elephant ears yesterday. So if I start them in pots, It won't hurt to transplant in the ground when it warms up?
I can safely plant June 1st. What size pot would you suggest? Mine are Caladium Esculentum.
I'm glad I found this thread.
Hi Liz -- the esculentum part means edible. I'm not familiar with an edible caladium. The most common green elephant ear is Colocasia esculenta. I've heard of caladium being confused with colocasia. The largest caladium I've seen has 18-24" leaves. Colocasia can reach more than two times that size. Caladiums are grown for their colorful and patterned foliage, while Colocasia esculenta are solid green. Caladium bulbs usually come in small clusters, while Colocasia esculenta are sold as large bulbs -- often softball sized.
I like starting them inside to get a jump on the season. I have lots growing indoors now. The color and texture develop much more for me once they are planted out. As for pot size -- large, especially if it will be a while before you plant them outside.
To avoid disturbing the roots in transplant, you could use a rose-grower's trick: grow them in plastic grow pots. When you're ready to plant, cut out the bottom, place the pot in the hole at the right depth. Slit the side of the pot and raise it out as you back fill.
I'm not nearly so cautious, but everyone needs to figure out their own level of comfort in handling tender parts of plants.
Thanks PR I just went to goggle, they said colocasia esculenta was the scientific name for caladium esculentum. I'll get them in pots today. We woke up to snow this morning....
BTW they are softball size or larger.
I would like to know how much residual I can have to wash my caladium bulbs in chlorine without damaging the bulbs
Glad to help, Liz.
Chris -- Chlorine is a gas (at room temperature when not pressurized) and is dissolved in water for use as bleach. Clorox is 5% Chlorine (95% water), I think. The USDA-recommended dilution of chlorine bleach to use as a disinfectant is 10 parts water to one part chlorine bleach.
Chlorine will evaporate entirely, leaving no residue, before the water evaporates. Most chlorine bleach contains added fragrance, which lingers after the Chlorine and water are gone.
Just got my first Colocasia, huge and lovely...thanks Rik, I thought I could leave this one sitting in water. I'm a water gardener, and am always amazed by plants that will grow submerged when they are sold as dryland...seems the EE's aren't in that category. Would have hated to lose the tuber...fun following threads, would anyone like to correspond with a Zone 2 crazy person? Tropical plants indoors and out...my best loves!
I have elehant ears I planted about one month ago. two of them had not come up yet and I dug them up. They are about half rotten what can I do to save these, cut the bad off or is there something I can put on it to help it from rotten all the way thru?
vcrampton -- Lots of people grow Colocasias as marginals. I've gotten many of mine from an aquatic garden shop. I'm not a water gardener (yet), so I can't really offer advice. I have noticed that they consistently grow much larger in soil than in water.
kimbo -- About your rotting EEs, get a spoon and scrape out all the soft, squishy parts. You might also find some parts that are kind of feta-cheesy. Scrape that out as well until you reach clean firm tissue that is like the inside of a raw potato. Wash it is soap and water, then soak it in water with a splash of bleach for an hour. Let it dry, and leave it until the cleanly scraped part dries and sort of scars over -- the surface will become opaque. That may take a day or two.
Plant what is left in fresh, sterile potting medium (not re-used). You might want to try to leave the newly scraped part above the soil to try to keep it dry and avoid it's vulnerability to the return of bacterial rot. When you water, splosh some Hydrogen peroxide in the water (some recommend two cups per gallon of water -- I'm less precise).
Make sure the soil you use is light and allows plenty of air-flow. Add perlite and sand if it seems like it might pack. Keep the soil barely moist until you see new growth. If you lost the main eye to rot, you will not have one large plant return, rather several little shoots will form around the outside. You can let them stay together in a clump or, when each one is well developed and has its own root system, you can separate it from the parent rhizome.
Sometimes it is fairly easy to stop bacterial rot this way, and sometimes it returns persistently and is impossible to stop. Don't feel bad if you don't manage to save them.
If you need to replace them, just make sure your soil temperature is above 60 degrees when you plant them out and plant them where they will have good drainage.
Wow!! I think I planted them in the wrong place. Pretty soon wont be able to get to front door. LOL. Thanks for telling me. Yours look great, hope mine do!!
It was their second year, but don't be surprised if yours reach five feet this year! Pour on the fertilizer. They really respond to it. Each leaf could be nearly twice the size of the one before.
PlanterRik, They are growing everyday. I took another picture, See if you can tell a difference from the last picture. I don't think I want to give them anything that will make them grow more!LOL, I have alot of them. I sure didn't know what they were when I planted them as bulbs. Here is another picture. LIZ
I definitely see the difference! That's as close to instant gratification as a gardener ever gets!
As they get bigger, they may lean over and hide the plants in front of them. You might want to drive a broomstick in the ground at each end of the row and run a strap across to hold the leaves up and give the lower plants some light. When they get really big, each leaf needs its own stake!
The ones in my picture were planted in a narrow space between a bay window and a retainer wall (I'm on a mountainside). If I hadn't staked them, I wouldn't have been able to pass. With them staked upright, I could walk under them! It made a nice bower. When it rained, I could walk from the back door to the greenhouse without getting wet!
If you have a large open space for them, they'll form a mound 10 feet across of giant black leaves.
PlanterRik, Oh my, thanks for so much information, always appreciated! As I was trying to take all that in I'd like some info. on AOLCASIA MACRORRHIZA also an elephant ear. Thankyou, Denise
Denise -- I'm glad you found some useful information here. What would you like to know about Alocasia macrorrhiza?
PlanterRik, How exactly to you care for that particular species, you covered alot but not on that one and this is new to me so I need all the help I can get, lol but true! Denise P.S. Is this a shade lover, how long does this one take to bloom and how much water does it need? Thanks!
To start with, it's useful to note the difference in genus. This thread has been mainly about Colocasias, and you are asking about an Alocasia. Different species of Colocasia can require very different situations to thrive, and Alocasias vary even more widely. Alocasia macrorrhiza is one of the most popular and easiest to care for. It's cell structure is denser than most Colocasias, and the leaf surface is somewhat glossy, while most Colocasias have a matte surface. Both of these differences result in its maintaining moisture within the plant better and longer. It is less prone to drying out, and when it does get dry, it will recover more quickly with less foliage loss.
The other side of that coin is that overwatering and poor drainage can be more of a problem than with Colocasias. Many Colocasias are grown as marginals -- around the edges of ponds or even in shallow water. If the water is very well oxygenated, some Alocasias might grow as marginals, but I haven't tried it.
For general care, I would recommend rich soil that is very well drained. In pots, I start with a good quality potting soil, add perlite and very fine, slightly composted bark that is sold as "soil conditioner." The fine, composted bark can also sometimes be found as "organic growers base." It has the consistency of coffee grounds. In addition to helping with drainage, the bark decomposes slowly, releasing nitrogen and other nutrients. I use, roughly, two parts potting soil, one part fine bark, one-half part perlite. You can add a time-released chemical fertilizer (balanced or specialized for foliage plants). You could also add composted manure (I use about a half cup to a cup per gallon of pot size). I use both, plus a liquid fertilizer. That probably sounds like too much, but these tropicals really respond to it.
Many people add Ironite to supply micronutrients. If you have access to earthworm castings, they are very good for establishing a healthy bacteria and micro-organism population in your soil. You could also just put a few earthworms in each pot. I make a point of putting worms in pots of elephant ears because rotting elephant ear roots are one of their favorite foods. So, if you should have a little rhizome rot (and who doesn't?), the worms will clean that out and prevent it from spreading and rotting the whole plant.
I think they do best in partial shade. They are often grown in full sun, but I think their foliage is a richer green and the surface keeps a nicer gloss, and the plants hold more leaves in 50-70% shade. If they are not getting enough light, the stems will become long and weak and will not be strong enough to hold the leaves up.
Variegated Alocasia macrorrhiza is becoming more available now, and it is a beautiful plant. Here is a small one I had on my landing among my coleuses and other small ears last year.