Can anyone explain the exact nature of the relationship between hardiness and age? I have read some say it is diameter, but I know that's not true because I've seen thumb-sized branches survive on older figs when even larger ones froze on younger ones of that same variety. Anny help to understand this would be appreciated.

Maybe some of the more wise will chime in, but my understanding is that some are more cold tolerant, those that are, become more so as they gain age and diameter, the larger girth being less susceptible to damage,,,

From what i have seen,when exposed to frigid cold,a fig tree will chose to save the youngest branches ,at the base of tree and let the older ones die.
I think it pump some antifreeze,in the young base branches,with all the energy it got,while letting the older branches die,by not pumping any antifreeze in them.
My opinion is that the fig tree is capable of saving itself,when faced with very cold Winters.

Thanks Herman,

I'll explain why I am asking and maybe  you can advise me when you have time. I am in zone 7b. I have several young figs in the ground and a few in pots. I tried doing a minimal protection of my figs two years ago, but they all died to the ground. Last year they also all died to ground. But I see older figs in my area that are quite large so I am trying to figure out what to do.

I have thought about reshaping them to step-over figs, but my goal is end up with small bushes 6-8 ft tall and 4-5 feet in diameter. I am thinking this fall I will cut them back to main scaffolding and then insulate with leaves and cover with trashcans. If I do this until they are 6 or 7 years old maybe they will survive without any help. What do you think?

Older figs are less vigorous. This allows the shoots to harden off longer in summer/fall. The hardening process results in higher levels of carbohydrates in the shoots that act like antifreeze. Those shoots that are green in fall have no chance in marginal climates. The brown shoots that quit growing early and are high in carbs will be the hardiest.

Try to slow your plants down as early as possible in fall. Reduce water, pruning, and nitrogen fertilizer.

Yes Steve explanation is ,true.

Thanks Steve & Herman!

This forum is always such a helpful place. If only I can actually put  into practice everything I learn on here.

I'd recommend no water after August and July would probably be even better. Figs are native to areas where it doesn't rain all summer. Cut off nitrogen even earlier. Pruning stimulates late growth. So trying to keep the tree small may be self defeating. Copy what's being done by those with big fig trees. They're probably not watering, pruning, or fertilizing at all. Cutting off water and fertilizer completely would be a better way to keep tree small than pruning from hardiness standpoint.

Yes, this thread is very informative thread but it would be helpful to distinguish in-ground figs from container figs.  The idea of stopping fertilizer earlier would seem to apply more to container figs while stopping water would apply to in-ground.  For my in-ground figs I haven't watered or fertilized them all year.  My soil is already pretty good.  I do need to give them some lime though.  Because they all are growing back from the ground or from 1 foot tall stumps it seems inevitable that there will be a lot of green shoots next Fall that aren't hardened off.  Here's hoping we finally get a mild winter.

Potted figs need way more fertilizer than in ground. And they are usually protected in winter so hardiness is usually less an issue. On decent soil in AR or MD established figs shouldn't need any watering. You want growth to cease by early August. Figs on later growth won't mature anyway.

Hi Genedaniels,
For me cold hardiness getting better with age is just a wish of the growers. IMO, Such a thing does not exist.
In 2012, most uftis I know of died to the ground, even some 20 years old (20 already... man I'm aging ) .

But, local conditions can help make a fig tree more cold resistant.
The first thing is the dirt. All my trees planted after 2012 are in holes full of dirt from the nurseries.
My dirt here is full clay and fig trees don't like wet feet during a cold spell . The dirt should drain well. So replacing the dirt helps them in keeping the feet drier.

One can't compare a fig tree planted in a "green zone" to a tree planted in a suburb or in town. In town, the temps are 5°c warmer . Houses do cut the wind blow .
In an open area, the fig tree takes the full blast, and that's bad for the tree. In that last situation, using the trashcans have proved to be effective for me, so far.
Do not forget to put dirt from the nurseries inside the trashcans as that material will take and release humidity and that helps the stems for not desiccating .
Dirt from the nurseries with a plastic bag to get the dirt to hold on to the tree has proven to be effective as well.
Is the dirt from the nurseries or is it the trashcans, or the association of both that does the trick for me ??? ... I'll use both as I just don't want to lose my fig trees when they at last get to fruit production age !