This past winter/spring I attempted rooting some cuttings for the first time.  I had about a 10% success rate with failures at every stage.  The two that survived are doing very well, but I'd like to see better success this fall/winter.

Heat certainly affects the speed of rooting.  It has been discussed in detail by those much more expert in the process than me.  In a nutshell, it does speed up the process but also creates mold issues depending upon what method you use.

Hi Tim
I think the 70-80 degrees that Jon mentioned was arrived at through experience/ experimentation as the best temp range for rooting.... and that is why it is recommended.
Last winter was my first season rooting fig cuttings. I had about 80% success  rate.  I used a reptile heat pad to heat  a covered aquarium in which i kept the baggies of spagnum moss and cuttings.  Cpvered, and with insulation wrapped around the aquarium, the heating pad kept the aquarium in the high 70's low 80's.  I had some trouble after potting the cuttings up. Some, after producing initials and being potted up, seemed to stop all development. I figured this was most likely because they were no longer as warm as they were in the aquarium. I rigged some shelves over heating vents to keep them warm and this in most cases solved the problem and got the cuttings back to making more roots and leaves. 
The one thing I would do differently this winter is start the cuttings about a month later. I would do this because even though I can set up shelves over the heating vents, because heating vents are situated at outside walls the area has wide temp fluxuations in the colder parts of winter.

Grant
z5b

Dormant cuttings will root quite well at room temperature (70 to 80 degrees). IMO, there is absolutely no need and absolutely no advantage to applying any additional heat to them when you are rooting your cuttings "indoors".  In fact, there is a BIG advantage to keeping the rooting environment at a near constant temperature level.

Heating mats (or the more appropriate name....."temperature controlled" propagation mats) are designed especially for germinating seeds of plants that all have "tap roots".  Fig trees propagated from cuttings WILL NOT have any tap root. Also, propagation mats are intended to be used in an "OPEN" rooting environment (i.e. not in a closed storage bin).  Open rooting environments are like those used in an OUTDOOR green house....that is open to the air.

When you use a propagation mat under a "closed" rooting environment, you will cause "uneven" heating to occur on that storage bin. This uneven heating will cause the humidity inside of the bin to get over 100% relative humidity (in other words it will becom supersaturated). This in turn will cause condensation (very "pure" liquid water) to form on your cuttings, on the opening buds, and even on the emerging roots. This condensation can be very damaging to newly opened leaves and newly formed roots.......because this moisture is so "pure". The high purity of this condensation can extract "food" from those leaves and from those new roots through a process known as OSMOSIS. That food that will be extracted by that high purity condensation will become the stuff that mold will use to grow upon. You DO NOT want to make food for mold to grow upon. You do not want to see "pure" water coming in contact with newly formed leaves and/or roots. To keep this from happening (and causing mold), you simply DO NOT HEAT your baggies and DO NOT heat your rooting bin. Again......there is no need to apply heat when you are rooting "indoors" at room temperature (70-80 degrees).

Bottom line.....if you heat a "closed" rooting bin with a heating pad or a propagation mat, you will significantly INCREASE the probability that mold will form on your cuttings. AND it will cause more damage than it helps. NEVER EVER apply heat to a "closed" rooting environment (closed baggie, or closed rooting bin).
-----------------------------------

I hope this makes sense to you. Rooting fig cuttings with a high degree of success is very very easy to do. What I have written are the main reasons WHY you do not want to use a temperature controlled propagation mat.......or worst yet....a heating pad. 

Of course there will be some that will disagree with me. And that is OK. But, I can bet that they do not have the high success rate that I routinely obtain in turning dormant twigs into established and plant-able fig trees. And remember that the rules that apply depends on whether your rooting environment is "open" or it is "closed". If you understand and apply this simple concept to your rooting method, you WILL see an increase in your success rate. I guarantee it.......

Dan
Semper Fi-cus

Alan,

An "ideal" rooting environment is a closed bin that is actually kept within a temperature controlled incubator (or hint hint.....food dehydrator). The "even temperature" that occurs under this ideal condition WILL NOT allow any damaging condensation to form in the rooting environment. It takes an actual temperature differential (i.e. uneven heating) before any liquid condensation can form. When condensation does not form.....no new food for mold will form......therefore, you will not have any problems with mold under a near constant rooting temperature level.

I could write an entire chapter in a book describing all of the fig propagation experiments that I have conducted. Yes, this works well. However, it is absolutely NOT NECESSARY for the average everyday fig rooter. I've done these experiments in an effort to better understand the rooting variables and to improve my rooting methods. Keep in mind that I am a fig researcher......in the truest sense of the word.

All the average rooter needs to understand is that dormant fig cuttings WILL ROOT quite well in those high humidity "closed" bins if you keep the temperature (nice and stable) and at room temperature. Should you apply outside heat to that closed bin or to those closed baggies.......you are lessening your chances of rooting those twigs....because you risk creating MOLD on those cuttings. Mold is often created by the "osmosis" mechanism I have described.

Regular tap water is differnt than the "condensate" that forms from using a heating pad. They  DO NOT have the same effects on tender new growth.......that is key to understanding the origin of mold on your cuttings. High purity condensate can cause "the cells" of  newly created leaf tissue to actually "BURST" the cell walls (from osmotic pressure) and release the cell's inner contents into the rooting environment.....ie. releases food for mold to grow upon.  And it is the amount of dissolved salts that are in the liquid moisture that is in contact with the tender new growth.....that determines whether or not this "osmosis" thing will be damaging or not.  Condensate can be very damagins since it has no salts in it and it can actually cause cells that are not yet hardened off.......to burst wide open.

Dan
Semper Fi-cus

Tim,

My results are different. I have experimented with temperature ranges from 50-100 degrees and humidity ranging from closed containers to no cover at all. 90-100 degrees worked best as far as speed of rooting. Cuttings do not need the high humidity most folks strive for (which in turn contributes to mold issues). Just keep the soilless media slightly damp and the temperature in that range and you should not have a mold issue. If you must use a lid, keep it partially open to prevent condensation. Good luck!

Same as Ruben

I agree that too much fuss is made over humidity during the "initial" stages of rooting.........it matters more when up potting.

There are two kinds of humidity........."relative" humidity and "absolute" humidity. Those two parameters are completely different and in how they affect rooting.  Whenever the "relative humidity" approaches 100% in ANY rooting environment......then it becomes unstable and that is when the problems begin.

Keeping a corner "crack" on a bin cover helps keep the relative humidity from going above 100%. And keeping heating pads off that bin does that too.....especaily in the root zone. The corner crack helps in the bud/leaf zone. Unhardened off roots (i.e. tender new roots) that lie in the "root zone" can be damaged by condensation too. Why allow that damage to occur if it can be prevented?? I strive for a 100% sucess rate.....but, that is just me.

Dan
Semper Fi-cus

I opt for the reptile heater and aquarium for rooting because the temp in the area that I have during the winter to get cuttings rooted in is high 50's to low 60's.  Room tempurature would never approach anywhere near 80, except in the full heat of summer months. In winter, for economic reasons, the cost of heating, room temps range from low 60's at night to a high of 70 during day when people are home.  So an enclosed, heat and humidiy controlled space seems the best option even though it may present its own problems.
Once intials appear and the cutting is potted up, it is out of the aquarium.

Grant
z5b

Grant......

Great solution for your situation.

Dan
Semper Fi-cus

One thing I have seen through out the years as far as rooting is concerned is the more I mess with them the more trouble I have had.
with high heat you have to monitor them very closely and if that means handling them it will probably lessen your % of plants.
one broken new root can kill the plant it is an open wound that can easily get infected.

Hey Dan,
Could not have done it without the informative posts, by forum members such as yourself.

Thanks

Grant
Z5b

I appreciate all of the informative posts.  I'll continue my rooting trials this year and I think for those that I do in the basement I'll supply some extra heat to get things warmed up to a consistent 75-80.

I intend to publish some of my work one day. However, my main goal is to find those select cultivars that do very well in my area. Rain tolerant, and early/mid/late season cultivars that will allow locals to grow and have figs from June through November. I hope to have a short list of 4 or 5 preferred cultivars along with accurate growing and fruiting information to give to those Nurseries who will sell these special select fig cultivars. The Universities are not developing that information.

Right now, the retail nurseries in my area are clueless about figs. In fact the other day, I talked with a local woman who believed that the LSU Purple and the LSU Gold fig were just a "publicity stunt". She had no idea just how unique and different these two figs really are.......and that they were developed by a fig breeding program at LSU.  Why people in my area will not buy a Smith fig because it is not a Celeste or a Brown Turkey. Go figure...........

Dan
Semper Fi-cus