Give it some more time, may be silly youth. If the tree is very young, then it may just be calling it a day earlier than the rest of your trees.

My collection of smaller trees has most leave fallen off. The larger trees, especially my larger Celeste, still show green leaves.

The timing of 'predictive' dormancy's onset is primarily genetically predetermined either by the combined parental genetics in the seed, or genetics passed on during vegetative reproduction. The main triggers are increasing periods of darkness and (secondarily) reduced temperatures. There are however 'reactive' responses to influences like cloud cover, temperature flux, moisture levels ..... that can influence annual patterns.

Something I've posted before about cold-hardiness;

Plants begin preparations for dormancy at the summer solstice. Lengthening periods of darkness are the actual trigger, and when night length begins to become longer than day length, growth regulators (hormonal changes) cause the tree to change from the business of increasing visible biomass (making leaves and extending shoots) to the business of building layers of carbohydrate-rich cells in the permanent parts of the tree (trunk and lignified (woody) branches. In short, the tree begins to save energy instead of spending it to buy more leaves and branches. The tree is charging its batteries in preparation for the portion of the growth cycle in which it will be leafless and unable to produce enough food to power metabolism (trees use energy even when in deepest dormancy).

As day length continues to diminish, growth regulators signal the tree to begin to withdraw anything usable from the leaves. Carbohydrates and anything that can supply energy to the tree are translocated to the perennial tree parts. Chlorophyll is withdrawn from the leaves and they turn yellow. As this occurs, photosynthesis and accompanying auxin (a hormone) production slows and stops. A steady flow of auxin across an abscission zone (where the leaf petiole attaches to the branch) is required to keep the leaf from forming an abscission layer and dropping. Since the flow stops, the leaf drops and the tree is in the beginning stages of dormancy.

As chilling temperatures enter the picture, water migrates out of cells into the space between cells. This effectively increases the concentration of solutes bound within cell walls and lowers the temperature at which the bound water will freeze - the tree makes its own anti-freeze, and now, the tree is in deep dormancy.

Ficus c. is one of those trees that can be grown in areas where they never see frost or dormancy, or areas that get quite cold, where they take advantage of the dormancy response to allow survival during freezing temperatures. Cold-hardiness is genetically determined and will vary by tree, but the genetic offspring of each tree will have exactly the same level of cold-hardiness as the parent tree (except as is affected by cultural conditions other than cold - drought, e.g.). That can never change, even if the tree is exposed to gradually increasing cold for 100 years.

There was more, but I shortened it to stay on topic.

Al

If you asking if you can risk leaving it outside, I wouldn't test it at this age. Leaf drop can be initiated by over and under watering, and temporary drops in temperature. Some of my trees have stopped and started 3 times this season, because of the weird hot/cold cycles we had this season. I find in SD that most current-year rooted cuttings do not go dormant at all in the winter, even when the parent tree does. They seem to be striving to get established when they are young, and and then establish a more normal rhythm after a few seasons.

That was a good refresher on the subject. Thanks Al.

I would like to ask the same question from a different perspective.
If I have a number of plant varieties of the same age, size and in similar weather and cultural practice environment; and some varieties drop leaves early in the fall and other drop gradually like in a race to see which one will keep the leaves longer. Are the one keeping the leaves longer show indication of cold hardiness or is it just slows dormancy onset and no indication of cold hardiness?

Another question is about temperature variations effects on dormant plants. Temperatures in our area dipped down to -5C (23F) a few times during the last few weeks and the plants dropped all leaves. A couple of plants with heavy pots are still outside and the temperatures for this week are expected to be around 60F to 64F. What negative effects will happen to the dormancy/plant?

Cecil, this part of what Tapla said caught my eye not that the other part did not i leanred from that but this part

Cold-hardiness is genetically determined and will vary by tree, but the genetic offspring of each tree will have exactly the same level of cold-hardiness as the parent tree (except as is affected by cultural conditions other than cold - drought, e.g.). That can never change, even if the tree is exposed to gradually increasing cold for 100 years.

Out of my 4 adult tree's and the having parent of your unknown ive observed it over time it being the eldest by a year over the other 3. Its the last to ripen figs every year and the first to curl and start loseing its leaves every year. Now this is in my climate your may be different im not sure how that works as you should have a longer growing season than me. Im thinking and im not sure if tree actually responds this way or not , but just maybe since its the last to ripen and only ripens about 25% of the figs on tree before it get too cold here its at its most vulnerable and curls its leaves and want to sleep in my climate. Like Tapla says about the daylight being shorter it senses this but at a time when its at its height of ripening figs so bam its affected more than my other tree's that already have ripened there figs. But im just thinking and i dont know for sure if that actually is the case a combination of what i just said, less sun, still lots of figs getting ripe, and it useing lots of energy in doing that. But it does it every year. I just think for me its a very late ripening type tree and never really gave a lot of thought otherwise till now. The first several years when i stored it in garage it would get i call freezer burn on its stems and i would have to cut them real short, last 2 years it has done very well in storage, and i would have gotten rid of it but i enjoy the taste of the figs of this tree. Is it very cold hardy i think not as in early spring i have to baby this one more so than the others. So what i have observed is that this tree is not for my cliamte but for a warmer type climate paerhaps as yours. Hope you like the figs taste and hope this help you understand it a little more than me confusing you more. Oh before i forget the tree has little ones spread to Canada, New Jersey and Georgia and Texas, im anxious to how its leaves take shape and figs taste in these different parts in time to come.
Martin

Ottowan - If you're asking if how long into the growth cycle your figs retain their leaves is an indication of their cold-hardiness, the answer is NO. While there may be some observable correlation between indigenous trees evolving in common provenance, the correlation would certainly be obscured by the primary influence of photoperiod in nonindigenous plants.

"Another question is about temperature variations effects on dormant plants. Temperatures in our area dipped down to -5C (23F) a few times during the last few weeks and the plants dropped all leaves. A couple of plants with heavy pots are still outside and the temperatures for this week are expected to be around 60F to 64F. What negative effects will happen to the dormancy/plant?"

Likely none, at this point. As your trees are moved toward deep dormancy by increasing night length, it will likely be chill that finally moves them into a true dormant state, 'endodormancy', for a very short while. Once they have become dormant, chill time will release the tree from true dormancy and it will pass into 'ectodormancy', which I usually refer to as 'quiescence'. During endodormancy the plant will not grow even under ideal conditions. During ectodormancy the plant is fully capable of growing but the conditions are not always right (usually too cold until spring).

What you most need to guard against are growth inducing temperature extremes after the chill requirement has been met but before it is beneficial for the tree to commence growth. Any time the tree is exposed to several days of temperatures above 45* AFTER the tree has passed into quiescence, growth will occur. Trees that are growing will have lost virtually all resistance to freezing. Not only would the tree (or parts) be susceptible to death from the physiological effects of freezing, the tree could also use substantial stores of energy reserves to push foliage that will only freeze or die from lack of light well before there is any hope of that foliage providing any (energy) return as repayment for the tree's outlay.

Not that it's part of the original question, but within the dynamics of the trees energy flow/allocation/returns is where you'll find good reason to keep your dormant containerized trees as cold as you can (within reason) for as long as you can into spring, and why it is generally not sound reasoning, from a developmental perspective, to think that by overwintering your trees in a warm spot in front of the LR window they'll somehow have a leg up on those trees quietly resting in the timely chill provided by Mother Nature. ;o)

Al

Oh - Martin - You are right. I think that you are simply witnessing a tree that needs to be grown a little closer to the equator (longer day length) so lengthening nights don't make the tree too sleepy to be concerned about finishing your fruits. ;o)

Al

Thanks,
The reason I was asking was, I have some small plants that I'm thinking about planting this winter, and I plan on covering them with something like old blanket and maybe a tub on days that get down to about 30 degrees.
I hope they make it!
Some Forum members have told me I would be safe in doing so.
Cecil

Ottawan, i have the EL Sals in its 5th year and next door neighbor has the 2nd year tree from mine , his get the same sun. We were just talking today about the leaf drop as it was very nice 72 out today, anyways his tree he picked a ripe fig and it has several more that would be ripe in about 3 to 4 days most his tree has all leaves and only a few yellow, mine has lost 90% of its leaves figs have been gone for a while now. It is the youth of his tree i dont know, same amount of sun and also same soil and same size container so it might be youth of tree as maybe it does not have a good schedule yet on what to do, oh also that 2 year old gave him a couple dozen figs this year and he was really happy , during the time when we were getting ripe figs we were talking near tree and he picked a few and offered me and i said Dennis no way i have a lot of figs on mine please no as you only have this 1 tree and im just glad your getting ripe ones. I gave him a lot off my tree as i get a lot of figs off my tree's , his wife made a great tasting fig bread for us this year, my wife does not eat figs but thats ok, but she loves that fig bread go figure.