In my experience, even with optimal care, Caladiums do not reach their full potential indoors. They need more light indoors than one might think (though strong sun can burn them) and they like humidity. Caladiums actually require a dormancy. No matter what you do, they will die back for a rest in autumn, so they aren't year 'round plants.

I've heard of people giving their bulbs (or corms or rhizomes or whatever they actually are botanically) staggered starts to get around the dormancy issue. That is, starting some in say, March, then some in April, then May and so on, in order to have some Caladiums active indoors all year. I've never tried it myself, so I don't know if that works.

Karen made good points above. Caladiums need good light or the leaves stretch and the petioles don't hold up the blade parts decently. They do best with a lot of warmth, too.
I've had potted Caladiums outside in summer. They're slow to get started here where spring nights are cool, and they just get to looking beautiful about the time they need to come back inside. As mentioned, they will go dormant, and usually the change in light levels when I bring them inside initiates dormancy for mine.
I have yet to figure out why, but I have a very hard time keeping Caladium tubers alive through their dormant period. I can manage it with a number of other tender bulb/rhizome/etc. plants. I've tried digging them and storing them in perlite or vermiculite. I've tried leaving them dry in their pots. I've tried leaving them in their pots with an occasional light sprinkling of water..cool spots...warm spots. I've always had heavy losses.
If you can find some inexpensively, it's worth experimenting with them. IMHO, if they're priced very high, some other plant would probably prove more rewarding for the investment.

I have successfully stored them dormant in my basement. They come up in Spring in their own sweet time, rather later than I expected -- at the end of May -- in the basement. If you cut them back you get a bushier plant that possibly could be divided. There must be a way to propagate them. It's true they are expensive, but for some reason I really love them. Usually variegated plants leave me cold, but caladiums seem so festive.

Ah, Monarda, you don't need to tell me... I find them gorgeous. Elegant. Classy.

Check out the blog

http://www.ianjudy.blogspot.com/

and its photobucket photos of the caladiums...

Many thanks also to karen715 and ooojen. Your advice is much appreciated. I don't mind to have them dormant for a while- if only I can wake the sleeping beauties at the beginning of spring! ;)

My college sweetheart used to grow these in Buffalo. He used to winter them over in the closet & bring them out in Springtime when they'd start a tiny little sprout. He pot them & hang them from some macrame hangers he made, & hung them in the middle of the room.

I can't recall if he stored them bare & dry or just dry in mix. I expect I'll see him tomorrow, will try to remember to ask how/what he did to them & report back. I do remember how beautiful & colorful they were, esp. after a long, gray Buffalo winter (where it can be gray from Oct. thru May; really miss the sunshine!).

Calathea..you said Caladiums are expensive in England. What about buying bulbs? Bulbs are usually cheaper than potted plants. A local garden center might sell them, if not, try an online nursery..Toni

Hi Toni,

When I was talking about expensive I was already thinking about bulbs- I have not seen any potted caladium around here.

Prices are something like 4 pounds (that's 8$!) *per bulb/corm/rhyzome*. No wonder one does not see many around...

I am also not sure whether one could purchase them over the Net from some Florida grower (25 bulbs for 20$, plus heavy postage, but still...), since as far as I understand the laws regarding the import of plants (or animals for that matter) are pretty strict here.

Well, I took the plunge and ordered two bulbs, your words of caution (and my mortgage) advised me not to order more. I'll pot them as soon as I receive them, read all that there is to read, and hope for the best. I'll let you know how it goes of course!

BTW let me say one more thing- I really like this forum. I am coming back to indoor/outdoor gardening after some years of intense traveling and/or moving around the EU, and of consequent neglect of my green roots. I have recently bought a house and poked a huge hole in the West wall in order to accommodate a large patio door for getting more light for the plants. So it is a pleasure to interact with like-minded people, and get advice and follow the always instructive discussions going on here. Many thanks to you all!

Hi Calathea..8.00 for a bulb??? Wow, that's expensive. I wonder why they're so high..
You said you ordered a bulb? That was a quick decision..LOL
Do you ever go to www.gardenwatchdog.com ? I'd take a peek, click the window to England, and look for nurseries. It's worth a try..you know?
Also, are there Walmart's out there? In spring, or as soon as outdoor garden supplies become available, they usually sell caladiums, well, they do here in the states..
Most hardware store that sell plants have various bulbs in spring, too.
8.00 is a lot for a bulb..look around, you never know what you'll find..but sometimes it takes work.
Good luck, Calathea..Toni

I grow them as summer annuals here. I start them around April indoors in a very warm grow room, which they love, then I move them outdoors in late May when summer temps don't drop much below 70 degress. By fall, they are starting to fade, not worth wintering indoors unless dormant. They hate cold, which could be a bit of a problem in England.

Sometimes I overwinter the tubers OK. I read somewhere not to store them under 60 degrees F. Sometimes they get too dry and don't make it. Sometimes I don't get them indoors before frost and they die.

I have a caladium growing indoors for more that a year without dormancy. It is huge, repotted three times, but has beautiful color and is magnificent. It gets good light but no direct sun.

i have a large 'Red Flash' caladium indoors for 8 years. since it's a large variety (large leaves), it has larger tubers. none of my tubers died in 8 years. i dig them up and store at about 60F indoors in plastic bins with holes - it provides a bit of protection against dehydration and keeps them dry to prevent rot. i have also overwintered small lance varieties - but with variable success. the smaller the tubers, the harder to overwinter them. the small varieties i keep in pot in soil until mid-april, beginning of may.

they are slow to start, unless you put them on a heat mat, in peat, and keep them moist and tented for humidity. then in about 5 weeks you'll get sprouts. otherwise it could take 2 mo to get them going.... i keep them on a heat mat until i have sev leaves on each tuber. then it's south or south-west window indoors and humidity has to be above 65%. mine is usually higher by may, around 75%. i have grown 'Miss Muffet', 'Florida Sweetheart' and 'White Queen' completely indoors - and they do fine. but ONLY if they get enough sun and you don't let them dry up. the soil temp is key, when soil temps drop below 65F, they go dormant. and keep in mind that soil temp is prolly 5F lower then air-temp. so ..if you can't supply steady 75F air-temps - forget it. AND they prefer 80-85F for good growth - that can be a problem in england, unless you put them outside? IF you put them outside, you still need to monitor night temp - HAS to be above 72F for good growth. If you have a southern or western window you temps will go 10F higher directly by the window. so at ambient 75F indoors in summer you'll get required temps for growth even indoors (without sweating too much :) ). in general they will grow for 6 mo and then decline. and need to be stored dry overwinter (in soil or not - see above).

they do go dormant when planted outside even in south florida, even in warm winters, when it's 60-65F at nite and 75F during the day. but of course some winters it can be 50F for a few weeks - that's too cold for them...but i'm talking about very warm winters when it does not drop below 60F much at nite - and they still go dormant.

i just realized that i have answered an ancient post :)...in any case, may be it'll be useful for caladium lovers in the north.

Petrushka-

I’m 5 years in the future and I’ve really appreciated your post. I’ve had my caladiums infoors for 4 months or so and they are starting to decline, i think im going to put them outside and see how that goes.

Ah-wee! we got future travellers!

what’s yr temps day/night? can’t be below 70F for growth.

Unfortunately once they started to decline the only thing that can keep them going is heat!

best 75-80F. so it has to be outsoors..

even so mine in southFL went dormant for 2 months: jan-feb. my temps never dropped below 70-75F , as i would bring them indoors for the cool nights/days.