What consistent temperatures must be reached for fig trees to break dormancy and push new growth.

In NYC, none of the in ground fig trees have broken dormancy yet.  Days are in the 50s and 60s, but nights are still cool, generally, in the high 30s and mid 40s.  Soil temps at night are cool.  Are warm days enough to start trees, or is it the root zone that must be consistently warm to support bud break and new growth?

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@ those Northern, short season, "fig shufflers" with still dormant, trees....any signs of life?

Do you think if the soil in a containerized fig tree is artificially warmed (light bulbs/heating pad, etc.) during the night, the trees will break bud earlier?  Daytime temps in 50s and 60s will support new leaves, and I'm thinking that warmer soils around the clock will jump-start the trees and extend the season.

The "shuffle" is to prevent/limit cold damage, especially on new, tender growth, when nighttime temps plunge into the danger zone.  If the holding area is NOT heated, but stays above freezing, then the containerized soil will be at ambient temperatures, and will still get very cold during the night.  Trees will stay dormant.  So why the shuffle if trees/soil are warm and sunny by day, and then, cold at night?  What's the point?  (I am not asking about doing the shuffle with trees that have already sprouted new leaves).  My guess:  root-zone MUST have consistent temperatures above 42 degrees to become, "un-dormant".  Yes....no???

So....what is the magic combination that triggers the end of dormancy?  Some documented science would help.  Just asking.


Frank

i'm not in north east, but my trees broke dormancy long before the night temp was above 32. they are all container culture, and they all stayed in the unheated, but attached garage. i remember reading somewhere once the night temp is constantly above 42 or so, the tree will awake. that's when the roots start to grow again. since the trees were in garage, there was no wind chill, and the garage was warmed by the sun hitting the south facing call outside. they stay about 10-15 degrees above outside temp. usually by late feb, all my trees are awake. 

the reason for the shuffle is not to wake the trees, but to promote quicker response and longer season to obtain the figs and growth that we are looking for. if cold damage was gong to hit the tree, it would have done the job before shuffle started. 

i think some members will do the shuffle daily.. i can't imagine how tiring that can be. but i only started this yr and i only leave the trees out when the night temp is well above 35 and there is no chance of frost. if the temp dips, they all go back in again. i think i did maybe 5-6 time this yr since march 8th. 

I live in zone 4 and started the shuffle two weeks ago,
Most of my plants broke dormancy in my garage with brebas first then the buds started to open.
Vito

Thanks for the response.  I will wait for a few more answers before I ask questions, and make some other comments.


Frank

Frank,

My 4th year in-ground tree hasn't broke dormancy yet in VA.  There's a fig tree about a block away, maybe a year older than mine that hasn't broke dormancy either.
Looking at an old post from last year, mine woke up by April 10th.  We're in the 70s all this week so hoping that will spark some life into them.  Hope this helps.

I would suspect it has to with root temperature, perhaps some type of heat accumulation like in persimmons (they require x hours above a certain temperature in order to break dormancy and initiate bloom).

This research paper seems to suggest there are different intensities of dormancy: Dormancy of Fig Cultivated under Moroccan Conditions

I'm extrapolating a lot here, but I would presume containerized figs that are shuffled do not go as deeply dormant as in ground figs, so they require less to break that dormancy. They would also be more exposed to warmth, accelerating the process further.

So far no signs of life. I went out yesterday to check and the 4 large trees that I have are still sleeping. At least I hope they are sleeping..

I am zone 7b (2 miles from 8a). All the older fig trees in town have broken dormancy. My young in ground figs are just barely started to do so. Does anyone know if that is normal, that older trees break sooner?

I have 2 year old trees with wood still green inside as ever, but have not broken dormancy.
Not just one of my in ground trees but 10-15 of them.
They budded much earlier then had a hard freeze, then they did it again and had buds breaking
but then another freeze killed back the buds. Not sure when the rest will wake up.

Doug

Thanks for the comments-

There has got to be some kind of a pattern that will reveal itself once we start to get more comments. 

Root-zone temperatures must have a great, controlling factor regarding dormancy and the start of growth.  Posts #2 and #3 seem to point to storage temps rising above 42 degrees at the root zone....otherwise, how can trees break dormancy especially in Vito's Zone-4?  It has to be the shuffle in combination with warmer soil temps.  I think.

Containerized figs, with their limited soil volume, can probably heat up quicker in the root-zone, than figs planted into the cold, moist ground.  Maybe shuffled trees will become active, sooner, than in-ground trees.  Anyone have a temp. probe?  Monitoring SOIL temps. when dormancy breaks, might be useful information.


Frank

Hi Frank,

In ground trees around here started to break dormancy the second half of February when the night time temps got up to the 45 - 50 degree range and day time temps were in the 70 to 80 degree range.

Our soil never freezes or really gets that cold down here.  I'm not sure what the soil temp was at the time.

Frank, at the same timing I have already put in ground last winters cuttings.
They are growing already, putting on new leaves and look great.

Weird winter here

Doug

I haven't seen any in-ground trees around here break dormancy yet but maybe later this week it will happen.  My two relatively young in-ground trees died to the ground (or close to the ground) even with some protection.  On both of them I see either green buds swelling off of the main trunk right around ground level or in one case two green shoots pushing up through the soil at the base of the trunk.  I think the dusting of snow we had a week ago monday slowed things down.

I was also going to mention that a lot of (maybe all) unprotected in-ground trees around here have significant cold damage.  I have been wondering how/whether cold damage sets back the date that the non-damaged wood starts putting out leaves.  So that could be another factor this spring which is delaying the exit from dormancy.

IMO it definately has to do with the soil temps.

Temperatures in a pot warms much faster up than inground.

My poted trees broke dormancy at the end of february/beginning of march when the average temperature in my basement reached around 50F°.
The inground trees are starting to break their sleep now, after a week of around 68° at daytime and 50° at night...
But we are over 50° at the day for maybe 6 weeks or so.

Rewton I have been seeing exactly the same here I have yet to see a tree in ground break dormancy and I am sure there is a lot of die back due to the severe winter, usually by April 22 there are leaves and buds breaking all over the place on fig trees I am very worried I hope the more established trees in my neighborhood survived my own in ground tree is definitely alive I can tell but not a bud in sight!

So far all indications seem to point to consistently warm soil/root zone temperatures as the trigger that breaks dormancy....possibly longer day lengths/light hours, also.

So....do you think using some heat mats at night to warm the soil in containerized trees would help break dormancy sooner and thus, extend the season for those growers in cooler climates with short seasons?  Therefore, this shuffle routine: trees out in warm sunlight by day, then onto some heat-mats/light bulb wraps overnight to keep soil temps warm.  Hopefully this schedule would cause trees to push new growth sooner in the season.  If this works, then long season figs might have a better chance of ripening in the colder climates because main-crop figs will be set earlier in the season.  Make the trees "think" it's May/June when in reality, it's still just April.  More heat units might lead to earlier main crops. 

Just a theory.


Frank

Forget the pattern ... we are now almost into May 2014.
Last winter crazy brutal cold (NE region) must have put them
into a very deep sleep and one hopes only that they are still alive.

My Negronne, Battaglia and Calliope's Red Greek are in containers and have been in our detached garage all winter. I put them outside for good last week. The Greek has 1" leaves at the end of each branches and the other two have buds opening. The Negronne has several round pea sized round growths that I'm guessing are small figs. That would be great since we really like the figs off of this tree. The Greek has small round growths too. One of the local figs I grew over the winter ( Kearney NJ dark unk) has a bunch of nickel sized figs on it.

I agree gorgi, usually mine have all leafed out already, some are just cracking buds now.  When I started pruning off dead wood, sap was flowing and not all had the milky sap, some was still clear so I don't think they will all have leafed out until another two weeks, we will see if I get any main crops before half september this year.

In general, my in-ground tree buds out in late May despite warm air temps in most of April and sometimes getting into the 80s in early May.  So far it's been in the high 70s several times with only occasional night time temps in the 30s for the last 3 weeks. 

My concern with my attached, unheated garage is when plants bud out too early and I can't put them outside because it's too cold.  I try to keep the garage as cold as possible in April.  I leave the garage door open when ever the temps are in the high 30s and low 40s at night (because the daytime temps are high enough to cause emergence from dormancy).  I have too many for my available time to shuffle.  As it is, now that I don't expect low temps any more, I get home after dark and bring out plants for 2 hours (cataloging them takes time) and I can't get all the ones out that have leafed out from the garage into the back yard.  Some budded out while it was still in the low 30s at night so they got leggy.  The ones highest off the ground and in the smallest pots seemed to leaf out first.  The ones at the edges of the pile leafed out before the ones in the center.  Most of the center bottom pots still haven't leafed out yet.  All of that supports the root temperature hypothesis as the cause for breaking dormancy.

In other news, my long season figs get brought into my grow room 6 weeks before I expect to bring them outside.  That's because for the larger ones, 6 weeks of growth is all I can handle in there.  This year all the tall ones are getting cut in half.  Then I can bring them out of dormancy 2-3 months early, giving me up to 8-10 months of growing season if I let the last figs ripen in the grow room at the end of the season.

Frank,
From observing dozens of in-ground NYC Fig trees for the past 2 springs (2012 and 2013), bud break occurs when the air temperatures are consistently above 50 deg F. (50's nights and 60's days) with soil temperatures above 45 deg F.

From experimenting with potted figs in the past 2 winters (2013 and 2014), plants moved from full dormancy, 30 deg F (30's)  to above 45 deg F ambient temperature (45 deg F to 55 deg F) had bud break within 2 to 4 weeks and had visible new root growth within the first week.

light is not necessary for bud break and initial growth, just increased ambient temperatures, the potted fig trees were kept in the dark.

BTW, there is extensive cold damage on many of the in-ground fig trees in NYC. I was able to prune 5 of the larger trees that I've been documenting and most of last years wood is dead on all the trees.

Hi Bronxfigs,

It all depends on the cultivar - yes I know that's an easy answer, but :
All My 3 "goutte d'or" have already 3 big leaves on all the stems - search for a photo I posted last week about trees awaking - that is one of my "goutte d'or"
My "Dalmatie" tried to grow but the leaves are almost red - meaning they would like to get more warmth. So the leaves are still small and enveloping their buds.*
My "Sultane" still has the bud's covers - so no new leaf.
My young "Madeleine des deux saisons" has already 2 leaves per stem.
My "Ice crystal" got its first leaves cold-burned - ain't that comic ? - but now has 3 leaves per stem.
All My "Unknown from the Italian" are still waiting - since last week they have 3 strong small leaves around the buds - and some brebas (almost half of them) got cold-burned .
My "unknown Brunswick perhaps" has one big leaf and a small one per stem.
My "unknown ronde de bordeaux perhaps" - the higher tree - has 3 leaves per stem and as to her habit is skyrocketing .
My "unknown from the neighbor " has lots of leggy shoots on stems with 3 small leaflets each.
My BT has 2 small leaves per stem and more figs than leaves :) - I like my BT .
My small "unknown bizzare BT" has 3 big leaves per stem
My damn "Longue d'aout" has 3 buds per stem with 2 small leaves each .

What got them all going strong were day-temps above 60°F/15°C and night-temps above 39°F/4°C.
They had that since beginning of April with some weeks colder and day-temps around 50°C/10°C and that stopped their development . We got 4 light frosts as of 1st of April with some nights around 2°C - perhaps a total of 10.

As for my "Goutte d'or" they are against a solid tree-wall on two directions and that might get them some extra °C which would explain that they are a bit in advance - or perhaps GO is a rabbit - I only got her 3 years ago.
I watered the trees as soon as I could and that was around the 10th of April and that gets them going good as well. When I water the trees I wash the stems and leaves - the trees seem to like that but I don't sing a berceuse for them

Bronxfigs, I would try a GH for serving your purposes and wouldn't heat the pot alone .
You could make a cheap GH with a wooden frame covered with a tight clear plastic - as some do here for tomatoes.

Thanks for all the additional information, suggestions, and observations, regarding dormancy and bud break.

I think I can surmise that root zone temperatures are the key to breaking dormancy.  Trees that are stored in unheated garages are leafing out....in ground trees, not so much.  Garages are probably about 10 degrees warmer than outside temps....so thus, warmer roots.  Consistently warm root-zones 45 degrees and above = new growth/bud break.

I am glad I asked.


Frank