Tree Dormancy

I am confused as to what makes trees and perennials go dormant. Is it the amount of light they are getting or is it the temperature?

I can take a mimosa tree indoors and it will continue growing as if nothing had happened. If I do the same with a Red maple, all the leaves will fall (november) off and it will go dormant. What is the trigger and is there a way to get around it, or bypass it?

Frank

Frank, I am trying to recall my plant science professors lecture..sure wish I would have been paying more attention. I am thinking he mention that it is the actual day lengths that cause a tree to go dormant.

Mmmm, I'm sure daylength has a bearing on a plant's habits, but around McMinnville, the wholesale nursery businesses don't dig their field-grown stuff until the first few cold snaps sends the sap down, and the tree goes dormant. In fact, they had a newspaper article on it just the other day.

From what I can recall from my college biology classes (way back) there is no "universal" signal that triggers dormancy in all plants. Some plants have no dormant period naturally, but one can be induced. Some respond by differing amounts of light, others to reduced temperatures, and still others by different amounts of oxygen/nitrogen in the atmosphere. Many plants change dormancy depending on the amount of moisture available (cactus for example).

The hardiness level of plants might give a clue as to what trigger, if any, will induce dormancy. Also the plant's natural habitat will provide (or suggest) cues.

I think all decidous (trees that loose their leaves) trees go dormant.....with the exception of live oak who does not loose it's leaves...but then again, i think all trees go dormant....
speaking of oaks, did you know that cork is from an oak tree? and mostly they grow in Portugal. Just a bit of trivia for you all....

This message was edited Friday, Nov 8th 4:57 PM

Here's a site on tree dormancy: http://www.ag.usask.ca/cofa/departments/hort/hortinfo/misc/dormancy.html Here's one on potted trees: http://www.suite101.com/article.cfm/337/85998 & here's another spot: http://homeorchard.ucdavis.edu/general-tree.shtml

vols, that is very interesting about the wholesale business up there. Here, the wholesale places can and do dig there field stock year 'round. The only time they really hate to dig is in August, due to the intense heat. Do you suppose the different zones make a big factor?

Lisa, I'd say the zones have a lot to do with it - I'd hazard a guess that a lot of the stuff that goes dormant in October up here, doesn't go dormant until much later (if ever) for y'all.

I was thinking of you today, by the way - I was cleaning out the pond (note to self: get hipwaders if I'm going to get in the pond in November...brrrr!) Anyhoo, the second generation of the water lettuce you sent me two springs ago is trying to survive the gradually cooling temps. I doubt I can keep them alive this winter, since I'm not heating the GH, so I may be emailing you in the spring, and begging for a few water lettuce and water hyacinths :)

(Ooooh, and thanks to you, the Louisiana influence is creeping northward. My SIL is tracking down a "tur-duck-in" for Thanksgiving. Ever since I told her about them, she's been on a mission to find one ;-)

Okay, now back to our regularly scheduled programming - what DOES cause trees to go dormant??? Inquiring minds want to know!