I have read plenty of posts warning about damaging or even killing a fig free if it already buds out and is left outside in the early spring when the temperature drops below freezing (less than 32F/0C).  What I would like to know is: is it really the frost that kills the buds or the below freezing temperature?  The reason I am asking is that I would like to get an early start by putting the figs out in a cold frame in the early spring when it's possible that the over night temperature would drop below freezing.  Since the plants are inside a sheltered area, they should not be exposed to frost, but might experience temperature that is below 32F/0C.  From my gardening experience, the vegetable plants would survive under this condition.

Thanks,

I put out my potted fig trees recently, I live at moisture, windy corner, One night, I saw frost on my lawn, temperature dropped near 2C for 2-3 hours, it killed all leaves.

I think that it is combination of both.

Around Niagara they worry about a hard frost killing the new fruit tree blossoms and the like. 
At this time of year the apricots are pushing bud and will soon at be at risk. 
Not sure what exactly they mean by "hard frost".  I think it means temps drop well below freezing for a sustained period and the frost forms.

Inside a coldframe the figs are protected from the wind and the micro-climate created during the day lasts through the night.  To be safe you should have a radiant heater that keeps it >7C at night.  
 
Next few days with the polar vortex going through (they are predicting -10-13C for Ottawa for 3 nights). 
You may want to consider moving the actively growing figs back inside for a few days rather than take the risk. 

It's temperature that's important not the frost you can see on the plant. The term frost is used to signify both a physical deposit of ice and temperature below freezing.

Physical frost would probably form inside your shelter. That's all about dew point and temperature. Dew point ie humidity will likely be high inside and if the temperature drops below freezing frost will form on cold surfaces, like your fig.

Thanks all for the response.

Ricky, sorry about your figs losing their leaves due to the frost.  I see just because the temperature is above 0C, it is not safe.

Pino,  a polar vortex is coming our way and it will dip to -11C this weekend.  My fig plants are still in the south-facing breakfast room (all four of them!) and I will probably just leave them there for now instead of putting them out to the cold frame, at least until after this cold snap.

Steve, thanks for explanation.  Now you brought up the dewpoint, it all makes sense now.

Cheers,

I have taken plants outside that got hit by real frost & cold temperature. I have not noticed any damage to the unopened bud but the newly opened leaves get frost burn and are goner. The damage too the new foliage sets the plant back by a couple of weeks with no other residual damage to the plant. 

Once  my plants are out of the garage, they are on their own, hot or freezing. I can't do the shuffle back to the garage because the garage gets easily filled up by the stuff that was moved inside to make room for the figs. 

Sometimes I protect some plants with a tarp of synthetic material. It protects the plants  from the frost but when the sun start shining in the morning until noon time when I go out, the leaves are burnt by the synthetic tarp when it get heated in the noon time. That is part of the game here with the figs when there is no greenhouse.

Once you have many fig plants growing, it would be really impossible to do frequent shuffling in and out of the garage.  This probably means one would have to go by the local last frost date (in our case, it's May 6th!).  I was hoping by using an unheated cold frame, I could at least move them out couple of weeks earlier to get them an early start. 

Akram, interestingly, I am trying to do this for the Early Violet plant you gave me.  I was hoping this would help the figs ripen in our region.

Alan, your points are well taken with regard to extremely cold temperature killing the fig trees.  My first fig tree was killed that way couple of years ago when I left it in the unheated shed over the winter.  Now, I am trying to explore the possibilities of getting the fig trees an early start in our cool region by using a cold frame to protect the young buds/leaves in the early spring from the occasional frosts.

Early voilet is named like this but it may not be early. It was not early for me at all.

Hi,

We just had 29 degree night in North Carolina & all the leaves on my newly bloomed celeste fig tree just wilted & dried up. Will the tree get new leaves or is the tree doomed. Tree is 4 feet high with a slight canopy

thank you

John  

The leaves (and most probably the figlets) will drop but the plant will survive and re-sprout new leaves. Plant will lag in growing process.

OttawanZ5,

Thank you for the reply. I will leave it alone then. So I should expect leaves again in month or so? It was a 1 night cold spell. We might get another freeze this Saturday. I better cover fig this time.

regards

John

I had about 20 small figs out early. They all got frost damage last night. Very risky being a lazy Fig grower this time of year.

It got to 29.5F at my house last night (under 32 for about 5 hours). I only see minor damage to my inground trees. The trees near the house (south and west facing red brick) only lost around 5-10% of leaves. The trees further from the house show about 50% leaf loss.

I actually covered a couple of the smaller trees with thin table clothes and they have more leaf damage than the ones that were left uncovered. I've got no idea why.

It actually got down to 25 in a mid April freeze last year and my figs had no damage to the wood. Just leaves and new growth died. My "hardy" pomegranates were another story. Of my four trees, two died and two died to the roots.

barnhardt says "I actually covered a couple of the smaller trees with thin table clothes and they have more leaf damage than the ones that were left uncovered. I've got no idea why."

If it was plastic table cloth then it should have been expected. Cotton cloth is safer in such cases.

Wow, sorry to hear that guys.  Hopefully they will rebound back quickly. That is exactly what I am trying to avoid. 

>> I actually covered a couple of the smaller trees with thin table clothes and they have more leaf damage than the ones that were left uncovered. I've got no idea why.

barnhardt9999, just curious, were the tale clothes very close to/in contact with leaves/buds?

> If it was plastic table cloth then it should have been expected. Cotton cloth is safer in such cases.

Akram, is it because cotton cloth is a better insulator than plastic sheet when in contact?

I am curious if any fig growers from North Carolina  or the surroundings had their fig plants protected by cold frames or unheated greenhouse and did not see any frost damages?

Bill,
Just from observations that when I covered a plant with synthetic cloth, i observed cold burns during the night due to plastic cloth touch and when I woke up late the sun had more damage when plastic was used. It is not just the insulation.
I guess that if plastic was not touching the leaves there may be no damage to the leaves due to cold near freezing but if not removed soon enough on a sunny day then heat trap may cause the problem,

We had lows of around 29 deg F for two nights and it looks like the brebas on my in-ground Adriatic JH have bit the dust.  The leaves had barely started coming out so they will probably be ok.

I have been spending 45 minutes on the colder nights schlepping the plants back into the garage. It really sucks and it's not over yet. I just had them in the garage for the last 2 days and nights here in NJ and put them out today. Looks like they will have to go in again tomorrow night.
Is this ever going to end?

Bill
Not early morning but a little later (if one is retired and sleeps well) and remove the cover after the hot sun has done its job frying the leaves under plastic cover.

Hi,
Here I heard that until the 4th of May, this year, we have a "lune rousse" / " redhead moon".
This particular moon is supposed to get us more freezes. It is something particular for this year.
So far, here we don't see that many freezes -Last one was last month or the one before - , but every 3 days we get 5°c during the daytime for some days, and that is slowing everything ... except some weeds !
Even, jonquils had a hard time opening their flowers .

Some more info about plant protection (before or soon after frost free days):

http://www.gardeningknowhow.com/plant-problems/environmental/protect-plants-in-freeze.htm

Thanks, Akram.  That is an informative article.