I forget which one of you trusted members claimed that fig tree growth becomes ever-hardy after it turns 5 years old; in any case, I have two questions:

1) I've noticed that plants in pots grow, in girth, MUCH more slowly than in-ground plants. What is this "5-year" mark based on, plants in pots or plants in the ground?

2) Is this "5-year" mark based on plants that started out their first year as 1/2"-caliper cuttings or are we assuming that plants are already a certain size when the "5-year" clock starts ticking?

In ground it takes 3 years average for mine to survive winters without any added
protection. Even when I get winter kill back, the new growth often is 4-6 feet of growth in one summer.
And still produces fruit.
My zone is warmer, and does give a longer season.
Not sure about zone 6, I moved from a zone 5, you don't see figs in ohio.
Those that do will be in pots.

Doug

I've never heard of a "5 year mark". I have heard that most figs can survive down to 20 degrees. I would imagine there are variations as far as varieties and length of exposure to this temp. I recommend that if you want to plant a variety in the ground when you know your zone will get that cold you should research what varieties will do well for you. On top of that I keep my cuttings in pots for 2 winters before planting in the ground. After that I wrap in ground trees forever. If you keep your trees in pots you need to keep them above 20 all winter. I think the main killer is "freezer burn", a combination of cold and wind that dries out the exposed wood and kills it.

All good info, since I live in zone 5a and am just starting with figs. So 20f is about the minimum survival temp, but what would the highest storage temp be so they stay dormant? I had planed on putting mine it the crawlspace of my house, but am finding out that it gets to be 60-65f. Garage wouldn't be good. Gets down to 10f or so sometimes.

Garage would be better than 60 degrees. Is there a way to get a small heater in there? Just to raise it above 20?

I am also in zone 5a. I have 40 trees in my unheated attached  garage. They are stacked against the house side of the garage with 2 tarps over them. I will put a small electric heater under the tarp with them during very cold weather. This has worked fine for the last 3 yrs.

For planting in ground, everything is about the environment around them.
Chill hours for your location limit or extend the growing season.
If you grow a apple tree needing 1200 hours of chill, it most likely will not fruit in a zone with 400 chill hours per year average.
Same with black sweet cherries.
Live and learn.

http://www.gardenality.com/Articles/1055/Resources/Calculators-and-Charts/Chill-Hours-Map-Chart-For-United-States/default.html
If I could grow oranges like they do in florida,, I would.
I'm just not in the right zone for it.
But I would have no need for a green house as I picked more than I really wanted already.
My season is plenty long enough for figs, but not suited for many other fruits.
Just my thoughts.

Doug

At the risk of jinxing myself:  I protect my in-ground plants well against winter wind and sun; but while I provide light insulation, I provide no artificial heat.  The only relative warmth comes from the earth.  With this system, I've had 6 varieties survive roughly -5 F (Z6 norm) for 1-3 winters.  So my guess is that a fully dormant, cold hardy variety can survive temperatures well below 15-20 F if it is protected from both cold wind and hot sun (early emergence).   

Great information!

I hope to contribute next season.

19 covered plants in ground, 3, 1' , mid July buried cuttings, and the rest >1 year planted mid July also.

Tied, insulated, covered, and the hope I did not murder my plants.

Good luck!  I have a Hardy Chicago in the ground in Kansas City, MO, Z6.  One year it was fully dormant, covered with a tarp and snow and there was a low of 17 degrees and that killed all the branches that were still outside. None of the cuttings from them survived.  Someone from zone 8 reported that all of his in ground figs would die back, regrow but never ripen fruit.  That's why most of my plants are in pots.  My in ground Hardy Chicago dies back to the ground every year but regrows to 12' with multiple stems and gives me lots of fruit.  If you try some outside, one should be a Hardy Chicago.  Bury it as deeply as you can. Fig plants come back from underground wood that didn't die, not the roots.

What Bob said, but for Sal's(Gene or EL) too.  There are probably several other similar 'Mt Etna' varieties that can survive the cold a little better.

I've decided to put mine in the garage next winter. The crawl space doesn't get below 62f. I'll just have to bring them into the house if it gets below 15f till it warms up a bit. I'll just have to keep it down to 4 trees or so. I don't understand how wrapping trees helps if they are in a garage though. I guess it might help with temperature swings or something. I do have one Chicago Hardy that I planted in the ground this spring. I mulched heavily to protect the roots, and we'll see if it comes back.

You may want to consider some of the winter proven unknowns that are out there. Check out those offered by forum member ADelmanto.

"Someone from zone 8 reported that all of his in ground figs would die back, regrow but never ripen fruit."

50% of the figs I picked last summer grew on 2 year old trees that died to the ground last winter.

I wouldn't bother growing figs if that happened to me.
Mine do produce almost always
after a winter kill so long as they are at least 2 years old.

The roots can not freeze and live.
The root ball needs to be below the frost line or depth of dirt that
freezes each year.
It was 36" frost line in ohio, 6" frost line in South Carolina.
If you are in a zone that keeps roots alive below frost line,
the tree should survive winter and just re grow stronger each year.
Doug

edit

"Fig plants come back from underground wood that didn't die, not the roots."

Excuse me but what do you imagine feeds the remaining wood?
The roots.

Leander Fig, if you have them in garage against house wall just cover the cold side and leave the warm house wall exposed, should help depending how warm the house is and how cold the garage is

<< The roots can not freeze and live.
The root ball needs to be below the frost line or depth of dirt that
freezes each year.
It was 36" frost line in ohio, 6" frost line in South Carolina. >>

Chester --

I'm sorry, but I can't believe that this is right.  I'll offer two observations.  First, I have a friend who has hundreds of figs in pots, which she overwinters in an unheated detached garage.  She lives in Z5b, where winter lows reach -10 F or worse.  The root balls in her garage freeze solid.  Sometimes they are still frozen in late April when she takes the pots outside.  She loses some plants, but the vast majority of her collection survives (otherwise there'd be no collection).  Second, the frost line here in Z5-6 reaches, as you note, many feet below the ground.  The ground is frozen solid.  I doubt that there is much of a root system below the frost line.   

To the contrary, I think that the earth is a huge heat sink that prevents the ground from getting much below 30F.  So figs in frozen ground are protected against really low temperatures.  Hence plants that die due top exposure tent to die down to the ground but no further.  Plenty of other plants survive frozen root balls, why not figs?  

I realize that there is a bit of a disconnect between my observations here and the experience of some growers.  It's still a bit of a mystery to me.  The one thing I know for sure is that my friend's figs are deeply dormant before / during / and briefly after the root balls freeze.  Achieving dormancy before really cold weather hits and maintaining dormancy while cold weather persists seems key. 
 

for your reference.
http://sqfoot.com/pdf/US_Map_Frost_DepthAVG.pdf

The plants in buckets that survive freezing solid roots is
a new one to me.
Not all zones will produce the same results when in ground.
Does anyone with dormant trees in pots let roots freeze solid?

Doug

Just to add,
my father in ohio put all his figs in a unheated garage.
Every single one (15) died.
he gave up trying to growing figs.
Not worth fighting the climate.

I agree with Joe D, figs will survive 25 degrees correct ? The ground would be frozen.

who stores figs at 25 degrees?
Maybe those living in the real cold zones could answer.
Im sure there is thread after thread on how to keep figs dormant.
None of them will tell you to store figs at below freezing temps.

I don't do the shuffle. don't need to.


Doug

Me too I agree with Joe D.
I leave on zone 5 
Most of my figs stay outside all winter covered with a  excavator's type  geotextile and a maximum of 3 inches of dirt on top of the textile.
Here the frost line reaches around 3 and a ½
feet deep. They pass the winter season fine even if they frozen dead as long they dont get the above ground wind .
What kills them the most are the dissecating winds that freeze burn them.  
If they are covered like mine they go trough winter  fine.

If you can grow fig trees in zone 5, good for you!
I have 73 in ground trees.
Tired of discussing it.

Doug

I left 100 fig trees outside in pots during winter 2 years ago and we had snow, freezing rain, and temps in the teens,all but a few came back in spring.The roots can freeze and live.All of my in ground trees do good unprotected until about Febuary when we experience real warm weather then a late freeze,thats what kills my trees to the ground,they all come back stronger each time.Someone told me that the warm weather makes the sap rise and if it freezes at that point it kills the tree?