Just a thought Susanne. I don't think any plant would be killed if you failed to rest it for one winter season. The worst possible senario might be that you would not get flowers. I know some people who do not rest some of their younger seedling Dendrobiums because they want growth. Den. aggregatum and jenkensii will continue to grow if watered frequently. My friend grows hers with her Cattleyas and they always flower nicely in the spring.

From my experience, the only one that absolutely HAD to be rested, totally...was my Ctsm Rebecca Northen. I know of folks who watered just a week or so too soon and lost her :(

I've now lost mine but it wasn't because of a rest or no-rest situation :bua:

"Dendrobium and its relatives" by Lavarack and Harris. 415 dendrobium species in full color with decent cultural notes, including whether they need dry rest, and how much. Some are something like "let dry for a few days", others are like "don't let dry for more than a day", so it's nice that way.

Cloudwinger, do you think that nature is that specific with its watering or with-holding of water. I certainly don't think so.

Hi Jerry, I jump in here for Cloudsinger, and can tell you that having worked as a plant eclogist for several years in Venezuela, yes, nature can be very specific. Normally orchids grow in very precise environment, very often in micro environments (ok, I admit that not all of them). In these micro environments, you have very stable and regular conditions, which can vary seasonally under also well defined patterns. You can also see, that when these patterns are affected, by whatever reason: global warmig (very trendy now), or just two large trees growing above were fallen, then normally the plants have difficulties to adapt to the new conditions. many manage to adapt, but other not, and those which does have a more or less longer period of "bad performing". In many regions, especially tropics, the rainy and dry season are very well defined, and it is normally during the rainy season that the plants "have this rest". In someplaces the dry season is extrem and last for 6 or 7 months, in other it does not rain during this period but there is some fog at night providing humidity, and in others it just never stop raining the whole year (you only see a difference in the intensity of the precipitations).

Therefore, we all try to understand which are the conditions under the plants grow in nature and try to copy them until certain extent in our artificial cultural environments.

I hope this help to understand why some plants need a stroger rest than others...

Thanks for the information Ramo'n. (I couldn't figure out how to get the accent mark over the o.) I guess my thinking is swayed by our changeable environment. We also have a wet and dry season. Our wet season is just ending and we get very little rain from now until June of next year. We can easily go for a month in the spring with no rain. However, some years, when there is an El Nino there is frequent flooding. The converse situation happens sometimes during our summers when we have a drought situation. So, the lesson that I have learned is that the weather in the tropics is quite stable compared to ours.

Doesn't most of the dendrobiums come from Southeast Asia and Australia? Dendrobiums seem to be the plants that vary such a great deal in their cultural needs.

I did not rest my Dendrobium senile last winter for just this reason. It's now triple the size and I plan to rest it this winter.

Ramon, do you think this may explain why there are so many different opinions as to resting a species like D. anosmum? There have been some here claim that full watering but cold periods will induce flowering. I have found that unless I totally dry mine out, they won't flower. Others have regimes somewhere in between. Just curious.

I have found that certain plants like D. anosmum, lodigesii, parishii, and pierardii (new name- cucullatum) to mention a few, will rest in the winter no matter what you do to them. You can always determine when their growth cycle is complete by the plants last leaf being half the size as previous ones. When this occurs the plant will not grow any more no matter how much water and fertilizer you provide it. A few years ago I hung mine with the vandas s where they received vanda culture all winter. At the end of February buds started popping. This was not my idea to do this but one copied from a society member. Flower count was good but not in abundance as you get when you provide the rest period. For example, I got flowers on only half the cane whereas with the rest, the entire length of the cane had flowers.

I look at the habitat and distribution when I try to figure out how to grow my plants. For instance, D. anosmum is pretty widely distributed - Malaysia, Laos, Vietnam, Philippines, Indonesia, and Papua and New Guinea in gallery layers of lower primary forests at elevations up to 1300 meters( and that's a huge elevation range) - so it's probably pretty flexible in its culture. On the other hand: Den. brymerianum -http://orchidspecies.com/denbrymerianum.htm
If you look, the distribution and elevation are much more restricted than anosmum, and so it's also a bit rarer. So it says keep dry just a little, but morning mists may be necessary, probably arising from it's mountainous climate that would normally be foggy in the mornings. So there may be a "dry" season in that the constant rains have stopped, but that doesn't mean that the plant doesn't get moisture from the air from the morning mist.

Dens are widely distributed across Asia(not just SE) and Australia, which is a wide area with a wide range of climates, which is why they have such a range of cultural needs.

Florida is not considered tropical, only semitropical, and I think only the southern portion, so I think that central florida is on the border between two weather types. There's a definite thermal gradient across the state, whenever we drive up to Gainesville, there's can be a 5-10 degree difference in temps, and an even higher difference from here(S. Florida/Miami) to Tallahassee. A lot of cold fronts from the north may push down to just south of Orlando, but never make it down to Miami. So probably even Miami is more stable climate-wise than Orlando.

So a few days ago the local news said that "they" had said that the end of the dry season was Oct 14, and it did cool off the last few days, but of course there is still activity in the tropics, so we(in S. Florida) will be back to the tropical patterns(rain!) in the next couple of days.