I'm not an expert but I don't think any of them "have" to go dormant. Just depends on if you have the correct enviorment conditions to keep them growing (Greenhouse or sunroom).

They will be by a window where they will get at least 3 hours sun and I have the area set up with 10 shop lights which the alocasias are growing great under now. Is that not enough light for colocasias? Also the temp. will stay between 65-70 all winter if we don't have the ice storm we had last winter. I will also have a humidifier going at all times.

I live near you in NW Arkansas and these will almost certainly go dormant.

I grow all my plants in a heat, humidity and moisture controlled atrium but almost all my Alocasia still go into dormancy. My really large Alocasia stay up but few if any of the smaller plants make it through a winter.

If you keep them in really bright light very near a window and keep the soil slightly dampened they might stay up. I have hundreds of aroids and virtually all slow their growth dramatically during winter. Be prepared for them to go underground for four or five months. The brighter the light and warmer the temperature the better the chance they will stay up. If cared for properly they will return in the spring or summer but some such as Alocasia Amazonica may stay down for a year or more.

You can see my atrium at the link below.

Here is a link that might be useful: Exotic Rainforest

erf if your primary source of light is the sun I can see why they will go dormant. My Alocasias have never actually seen sun light. The Colocasias are outside so they have probably already started the dormancy process. Less daylight hours and the lower angle of the sun will trigger this process. What I was wondering is do they go dormant in tropical locations? Guess I should have worded my OP differently. All my plants are in pots. I planned on putting the Colocasias in the window for the extra light since they didn't do well under lights when I got them. That is why they are outside.

That would be species specific. Some do go dormant just the same as Amorphophallus species have a natural dormancy. As an example, your "illustrus" is a form of Colocasia esculenta. That species does not have to go dormant but often does due to lack of light and/or temperature. There are hundreds of forms of Colocasia esculenta but only one species due to natural variation.

There is a link to information on natural variation inside the link below.

Here is a link that might be useful: Colocasia esculenta

I just posed your question to Pete Boyce in Malaysia. Pete is the best source of correct botanical information on this genus currently working. I'll let you know what he says but we will be in Miami beginning Tuesday for one week for the International Aroid Society meeting. If he responds before we leave I'll post his note.

Here's your answer directly from Pete Boyce. Few people know as much about Alocasia as Pete since he teaches botany in the rain forests of Malaysia. The Alocasia longiloba group he refers to includes Alocasia Amazonica which is a hybrid created from related parents.

"In cultivation in the temperate hemisphere my experience is that it is very likely that daylight length (or, rather darkness length) and an associated drop in diurnal temperature maximum serves to induce dormancy in the those species where dormancy ability is coded for. Here in the tropics one group in particular, the Alocasia longiloba group, have species (and hybrids thereof) that go dormant, even here, where daylight/darkness and temperatures are constant year round, implying that there may be some internal ÂclockÂ, with the Âalarm probably triggered by a genetic coding that relates to the termination of an active shoot module. It is interesting that the species here that Âdo dormancy are all rather few leaved. In addition these species can also go dormant out of sequence in periods of very dry/hot weather, and that is also almost certainly genetically coded as other species slow growth but donÂt shed leaves if the weather turns dry for a protracted period.

Another Âgroup that does dormany is Alocasia hypnosa, and possibly Alocasia fornicata. These are species from monsoonal areas of N. Thailand, Lao PDR, and Myanmar."

Quite a few striped hybrids also belong in this group.

I hope that helps.

Thanks so much for the info and link to site on colocasia. Some very interesting info there. Have a safe trip.

Hi all. Just wanted to let you all know that my plants are still growing although growth has slowed. I'm keeping the temp above 65 and the lights on for 14 hours. Seems like they would have gone dormant by now if they are going to at all. My largest Alocasia aurora has sent up two inflorescents and no new leaves in the last month but the smaller aurora is growing a new leaf now. I will be planting them all outside come spring and dig them after going dormant next fall. They were just a little to young and small to trust they would survive dormancy this year so I brought them all in to better ensure survival. Thanks for the help and may this year bring you bigger and better plants.