What causes ripening?

(1) Do figs work like corn, or melons? Do they need "x" number of days from their appearance or "flowering" till they ripen, much as the seed packets for melons or corn state "81 days" to maturity? The fruit which formed first at the lower part of the branch generally seems to ripen first, so seemingly time is a factor. My Black Madeiras will all "ripen" sooner or later, but when it is cooler, they do not develop the flavors and sugars that the ones which ripened in warmer weather developed, so time seems to play a role.

(2) Do they need "x" number of heat units (sort of like chill hours for stone fruits) before the ripen? Clearly ripening is retarded by cooler weather - at least I think that is everyone's experience. What is the minimum temp at which figs accumulate these heat units and continue to ripen acceptably?

(3) What is important in ripening, sunshine on the fruit or on the tree? When I cover a fig with a piece of newspaper to protect it from the birds, it seems to retard the ripening process, even though the air temp is still warm. Others which were not ripe. and thus not covered, seem to begin the ripening process and catch up with the covered fig. This leads me to think that direct sunlight has some affect, but figs that are in the interior of the tree, or the shady die, or in the shade seem to ripen fine, though it is hard to tell if they have been delayed. If they need direct sunlight, then they shouldn't ripen indoors, no? Or does the shade reduce heat, which is the real factor, and not actual direct sunlight?

(4) Clearly the hot spring weather we had, in San Diego, this season pushed the season ahead by 3-6 weeks, depending on the variety. They clearly were not leafed out 6 weeks early, so the affect must have been heat related, it seems to me. Would heating up trees in sheds and garages, or maybe bringing them indoors, give them a similar head start for people in colder climates?

Just thinking out loud, but maybe someone has some experience which supports or refutes some on my observations.

Great questions. In my limited experience, I would say that it must be more than time alone for ripening. My "Bella" unknown started forming fruit in early July. There were 30-40 fruit that were growing well but by late September they never ripened (70 day mark). By this time, the sun was significantly lower shortening the amount of sun the tree got. Temperatures also got colder. Even thinning out the tree had no effect in ripening the fruit. I would have to say heat & sun are stronger factors than time. Today, the fruit are still on the tree and I have cut open a fruit or two and they remain white inside and hard.

Jon great question, your question 1 ,
i think like different melons same as for differrent types of figs some mature faster than others, example my unknown always last to ripen and leaves unripen figs as well going into hibernation period.
You wrote
My Black Madeiras will all "ripen" sooner or later, but when it is cooler, they do not develop the flavors and sugars that the ones which ripened in warmer weather developed, so time seems to play a role.
I think yes very true, cooler weather plays huge part as my figs get rather bland when weather turns cold and stay this way and inside color of figs changes as well.
Question 2
I think right around 70 temp is minimum for good fruit taste but not sure about overenight temps as i only pay attention to nightly temps for overwintering. Then i personally think some varieties need a lot more heat temps than others to taste there best like again that darn unknown i have.
Question 3
Im sure the sun on the fruit will make them ripen slightly faster, as in my case on my patio the sun is at a slight angle in sky and shines on the one side a little more, that side of tree seems to have the figs turning first although the other side while not shaded is just a bit behind but not much, i do not turn the containers. I think they will ripen indoors in indirect light (coming thru window) but then the sun in window would move and not as much light on tree and i think they would take longer to ripen and would not taste as well as outdoors even if house was heated to a high temp as i think sun is very important factor for these tree's.
Your Last Question.
In my zone 5 trees are in garage that has a window panel on top that warms garage somewhat and faces east morning sun, when early spring comes i bring in and out of garage for more sunlight then back in at night because of freezing temps to perhaps get an early start . I have not kept recoeds of when i do bring them out and only started keeping recors laste last year as to when the tree;s give me ripe fruit and which ripen first. Overall from my own experiences sun and heat play  the most important role for me , aslo another factor i dont think they would do quite as good if planted in the the ground as the ground would take longer for our area to heat up and once tree;s are uncovered they risk damage if uncovered to early unlike going in and out of garage that i can control much easier. As for head start yes bringing them in shed or garage i believe does therfore give them a head start as to leafing out earlier because of the warmth more so than the sunlight as i have them covered with sheets in garage and maybe the white sheets let a little light thru them but not to much i think and was surprised that while temps outside are freezing or below early in season i peeked underneath the sheete to see the buds opening up already at this point i uncover but have to keep in garage as day temps are still at freezing, each year it varies and i need to start keeping records as to when they awaken from dormancy as i thin it would help maybe you and others to further understand the fig tree;s that most adore.
Sorry for such a long post and maybe going off subject but these are just some of my experiences growing in my area, also the unknown that i have posted in past is still giving ripen fruit that are soft, dark in color and different color inside like a brown sugar color mostly with a hint of red as opposed earlier at best stage a nice dark purple and red inside, there more a dirty purple and shades of green now but not to good to eat, i thru away 30 figs just yesterday, so to me this proves this type would like a warmer longer sunnier season to perform its best, a small plant has been sent to a forum member in Texas this season and is growing rather well time well tell the difference between his and mine although i think i already know who will get a much bigger crop of good tasting figs. Another thing that you might want to bring up is the somewhat different shape of leaves a tree takes on perhaps from area to area as well as i have seen some pictures posted of tree's that look somewhat different that are of the same type.
Best Health
Martin

Again, a GREAT question!
In spite of all the aswers you got/will-get; I think that it ALL is in the genes.
I have heard of figs acting (somewhat) abnormally due to local
different environments; but most do STICK to their early/late ripening
natural-schedule. If there is a "silver" bullet, apart that drop of oil onthe
eye, that hastens the ripening (but not taste) ... I do not know...

Gorgi, i have to add
well said!!!

A link to an article on some interesting experiments performed by UC Davis, UC Extension, Louise Ferguson, et al:

http://groups.ucanr.org/freshfig/Growth_Regulator/

In the experiments, ethylene releasing agents and ethylene inhibitors were applied to the figs and branches of different fig varieties. Results were mixed, with fig ripening being stimulated, but leaf drop also increased. At high dosages of the ethylene releasing agent, death of the branches occurred. Application of a drop of olive oil to the eye of a fig can also hasten ripening, particularly in some varieties like Hardy Chicago. I am not likely to utilize ethylene releasing agents on my figs. In regard to oiling, except when it is clear that figs will not ripen before frost, it is a good idea to let figs ripen naturally, as oiling the eye can have an adverse effect on the quality of the mature fig. As previously stated in this thread, heredity plays a large role in the ripening cycle of different fig varieties. In my opinion, both heat and the amount of sunshine also play a large role in the speed of ripening. In Austin, Texas, during the rainy summer of 2007, the ripening of many varieties of figs was delayed by several weeks. For the average fig gardener, the best way to optimize speed of ripening of your figs is to place your figs in a sunny area or trim overhanging branches that interfere with sunlight reaching your figs.

Mountainman,
I have also seen the article and likewise I am unlikely to use ethylene on my figs ;) but it seems you are in agreement with others on heat & sun rather than time. Time seems to be more of a genetic trait.

This all makes good sense to me i like what Gorgi said about the genes which i think every living thing has or most  anyways seems like a program of sorts that tell everything what and when to do there thing, what i think maybe overlook somewhat is growing in containers is the heat factor in the root zone as well it seems if one grows in containers placed on a warm surface that radiates heat into those containers they might slightly do better along with lots of sun as oposed to growing them in containers placed on say grass which might not radiate the heat into them as much ? Or like growing them in ground next to a brick wall which i think they would do very good as the warmth of bricks would warm plant outside and in the root zone thru the soil as well just me thinking again aboout the possibilties.

I believe the point of the question ( as I understand it) is that, for the same tree, what environments/conditions/care will make the fig tree ripen the fruit on time according to the plant's biological clock and what  environments/conditions/care (or lack of it) will delay ripening of the fig fruit. Of course different varieties will behave differently under similar/same situations and more so under different situations.

I am not an expert by any means (though I grow good cucumbers, tomatoes and hot cayenne peppers) but I strongly believe in the heat-units requirements with light being as catalyst for photo-synthetic nourishment (& a factor because cloudy conditions reduce the heat & thus heat units at the plants level) and no amount of heat-units in the dark will ripen the fig before the tree suffers because of lack of photo-synthetic nourishment. I also believe by intuition that the heat-units accumulated at temperatures around the optimum growth temperature will be the most efficient in ripening the figs whether accumulated in the calm open yard, at the south-side wall or wherever else.

So, what is that optimum temperature to accumulate the most efficient heat-units? I don’t know and we can wait for an expert to answer. In the meanwhile I can just guess (and forgive me for making too many assumptions here).

We know plant growth shuts-down between 15 degree C to 7 degree C (55F~45F); and dormancy breaks around 7C (45F approx) but I have read that the real growth starts around 15C (55F~60F).

I also believe that, just like a dormancy shut-down of growth at colder temperatures, there has to be a shut-down of growth at some upper temperature where the plant stops in order to conserve energy for survival just like some grasses do when they look brown and dead and crunchy to walk on but a good soaking rain brings it out of heat dormancy and greens it up again.

OK, I will stop my assumptions and rest the case for pickup by experts to insert correct numbers above.

Who knows why mine don’t ripen? May be because my oldest one is just two year sold but I am sure, and very sure, it will ripen early next year; with an early start of two weeks in the garage and then the pot with twelve1” dia holes buried in ground near south facing wall when the soil warms up. Nothing will stop it (except raccoons and squirrels).

Ottowan my observations are the raccoons and squirrels (and birds and wasps) are the cause of ripening. Not only will the breba figs ripening coincide with the arrival of the mockingbirds but they will be at their largest and very best flavor the more mockingbirds there are. The earliest main crop figs will ripen as the wasp population reaches its summer peak and the more wasps per fig available the sweeter the fig will be. In years of squirrel abundance the figs of late summer will always ripen before the walnuts, they will also be more numerous and of larger than usual size. If the finches show up early those late autumn figs will ripen to perfection before frost . I hope this helps.

I am sure there is a right answer to all of this, and I am sure we probably won't discover it any time soon, but it is good to get a variety of perspectives. I have enough experience/observation to ask the questions, but suspect that it will take a lot more experience to begin to unlock some of the secrets. Hopefully it gets some other people thinking and observing, so that we can all benefit, longer-term.

If heat is an aid to the ripening of figs, wouldn't partially surrounding a fig with aluminum foil aid in heating the fig, especially as the days cool off but the sun is still nice and bright? Would this be a way to test heat vs. age by leaving one fig unfoiled and another of the same age backed by a disc of foil facing the sun? An interesting thought especially since I have some big green Brown Turkeys unwilling to ripen.

So are you volunteering to do a quick test?

Good idea to try with aluminum foil but I am not sure if it is just the fruit that require the warm environment. I tend to believe that it is the whole plant system that requires the warm environment for a certain period of time including roots, stems, leaves as well as the fruit because there may be a symphony of actions and reactions going around in the plant system as a whole to serve the fruit to maturity.

Your experiment though may have some bearing on what Herman mentioned in his recent post about the last stage of ripening when the fig is almost ripe but some require a week for the last rush to swell to mature size and other may take shorter or longer time to swell to mature size.

I recall reading somewhere (can't remeber where) that putting plastic bags over the figs speeds up ripening. I think that would be at the final stage of ripening and be similar to the attempts at oiling. Haven't tried it but seems similar to the foil idea.

Alright. Two figs, same tree, same size, different branches, about a foot apart. This tree only gets morning sun. One fig foiled (tonight) one not. Leaves removed so both exposed to sun. It will be sunny tomorrow here, but cool over the weekend. We'll see.

Clearly ripening slows down around here when we have a cool week (somewhere in the mid-70s), and picks up again when it warms up (in the mid 80's and above, so that may give some insight into the temps required. Though, even in cold weeks, it doesn't seem to come to an absolute stop. However, the cooler weather comes with some early morning cloudiness, but it is generally gone before the sun would hit my trees on the west facing slope where they are located. So, I am thinking that temperature, or lack thereof, is more of an issue that sunshine.

Trying to balance all of these things, perhaps temperature is the primary input affecting ripening, and sunshine only adds or enhances the process - or provides some heat input?

The age of the tree is clearly a factor as well. Almost all of my in-ground trees (except Black Madeira and Panache - known long season varieties - and a very few others) haven't had figs in several weeks. However, trees planted more recently (this season, or last year) and newer ones still in 5 gallon pots are just coming into their season, in many cases, though some have already "synchronized" with the older trees. Late season warmth is helping me ripen these newer varieties. (135-15s is a definite winner.)

Trees that went dormant, or nearly so, (roller-coaster weather) and which have reflushed with new growth and fruit are obviously nowhere near ripening, presumably bumping up against the need to have a certain amount of time to "mature" before they are capable of ripening.

In regards to melons, I believe those days on seed packets are based on an early planting.  I've frequently not got around to planting melons in my garden until July and handily beat those numbers, so I think it's based more on day length, heat, etc. (at least for many melons).

Also, to develop sugars, photosynthesis is needed and that can be reduced by wind.  I had not heard of this until about 8 years ago when talking to someone who was selling tree shelters, but then I've observed it in many other situations since then.  For instance, one of my alfalfa fields is surrounded by trees on three sides and it grows significantly faster than any of my other fields.  This isn't heat-related, because it can be similarly hot in all of my fields.  Corn has also grown much taller in areas protected from wind (not due to lack of sunlight).  Jon, I wonder if your cooler weather is also accompanied by breezes.  Being on your hillside, that could be a factor, I imagine.  It would be interesting to set up some wind breaks (poly film?) to see what that might do.

Still, growth does not directly equate to ripening (some fruits will ripen smaller than others of the same variety in other growing conditions).

Ripening of lower fruits earlier can be due to time but also because of getting a first shot at water and minerals.  Don't know how much of a factor either might play.

Heat, heat, heat & sunshine. This is not scientific knowledge but simply 30+ years growing figs. My environment has to be a big factor also. My summers are long, hot, and quite humid at times.

When I say heat, my best figs ripen at 85-100F. Yes, 100F and high humidity is present quite often these periods. They also do best when there is lots of sun shine. The humidity has no effect on the ripening, but excessive rain does as it affects almost all growers. The ripening period starts about June 15 with some varieties and the ripening continues into late Oct and early Nov. My figs ripen very good in the lower parts of the tree where they are shaded some by the higher canopy. This says that heat plays a big role in ripening without a lot of sunshine.

The length of day is an important factor in many ways, especially bringing more heat and sun shine. All of my trees are in the ground and as the days start getting shorter, the older trees respond by stopping new growth and hardening off. This greatly contributes to winter hardiness. There are some varieties such as LSU Purple that continue to grow until the first hard frost bites them. I have a few varieties that are very late maturing the main crop in late Oct. These varieties ripen good figs without high heat.

To be a little clearer on ripening with or without a lot of sun shine, both are good, but the full sun gives a better colored fig.

Jack

A fellow gardener was visiting over the weekend, and, among other things, we were discussing the ripening of figs and he made an interesting observation: unripe figs are green, and thus he surmised that their skins contain chlorophyll and thus have photosynthetic activity. If that is true, then the ripening process most likely is affected by sunlight, direct and indirect, on the fruit.

Jon, I hope what you say about green fig and photosynthesis is only 50% true because my plants are crowded because of limited space. Also, I am not sure if being green is the only requirement for photosynthesis action. It has to have proper cell structure under the green skin to perform photosynthesis. The leaves have this cell structure. I don't know if the fig fruit has it. I hope someone with the knowledge can clarify further. However, I do believe that sunshine on fig is a catalyst for ripening (irrespective of the process whether direct heat or otherwise).

Just a thought following Ottawan's comment ... leaves have the capillary structure to transport the resources needed to produce photosynthesis products and to deliver them to other parts of the plant. I do not recall seeing similar structures in the green fruit. But of course I never examined the fruit for microstructures under magnification. Just thinking out loud.

I ain't no botanist (and clearly don't claim to be), but it was an interesting observation, which I can neither prove or disprove at this point. This post is still not about about what I know but what I wonder about. ;-))

Yes Jon, we know that many of us are no botanist, but some of us just add their own perceptions to an interesting observation until a botanist comes along to prove or disprove. Forums are great places to learn and learn and inform others.

I was just adding my thoughts also. I do wish I did have some answers to some things like this question because they make me wonder and scratch my head. It is fun to guess at it sometimes and makes for good conversation and debate.