It seemed like a good idea at the time. 

Followed by:

The sound you hear is the palm of my hand hitting my forehead.

Followed by:

The sound you hear is the palm of my hand hitting my forehead again.

We use a programmable thermostat to drop the temperature at night to 62 degrees.   Sunlight coming in windows warms the room during the day while we are gone at work.  I have been rooting several cuttings in the room and got the bright idea to add some extra heat.  I placed a bath towel over a seed heating mats and placed the bags (stems wrapped in newspaper in Ziploc bags) on the towel with a towel on top.  Didn’t realize until later that the temperature reached 100 degrees and the paper dried out.  One of the cuttings had roots starting before I put it on the towel.  It was only a few days away from placing in the clear cup.  The roots were destroyed; another had no roots but a growing green stem.  Green stem destroyed.   

Fortunately, these were duplicates with the exception an  alma.  It was one of those stems that will teach patience.     I rewrapped and I’m hoping that it may still come back.

The silver lining is the fact that I had just received some expensive and harder to find cuttings from a forum member and ebay seller.  I will stick with what has worked with the new cuttings. 

Still would like to explore adding heat.  I’m looking at putting some more distance between the cuttings and the seed mats and testing  using a thermometer before any plants go near the heat.  I hate learning the hard way.  Should have seen this coming and didn’t anticipate that a mat made for seeds would put out the kind of heat that it did.

Anyone using heat mats? 

I used heating mats but I use them with pots to root cuttings not bags, it has worked well for me so farm they only get around 85 or so.

I would definitely get a thermostat and set it at 82-85 degrees. Using heat mats accelerates my rooting time. Just be really careful drying them out. I did that with some harder to find figs!

You can always put it on a timer. Try starting out at 30 min "on" then 60 min "off" repeated for 24 hrs. As it gets colder out you may need to increase "on" time. Try the 30/60, just lay a thermomter on the towel and check it a bunch of times through the day to make sure what temps your getting (before you try it with more cuttings). I have done this with seeds and other plants and it has worked well. Besides, doesn't everybody have a timer and thermometer of sime kind laying around already? You might save 45 bucks, which you can then use to buy more cuttings :)

A looong time ago, I did purchase an ~$100 rubber heat mat.
It also came with an ~1" metal-wire spacer.
From my experience, it just 'toasted-dry' whatever I tried to grow on it,
in spite of a so called built-in-thermostat.

Currently it is buried somewhere among my basement mess/junk.

Good suggestion Calvin.  I have an old timer laying around and may experiment with the heater.  Also tried putting bricks on the mat and then a towel.   The bricks seem to generate a more even and lower heat range. 

Thanks again

Thank you for sharing your experience.  I thought maybe the problem was with my cheaper mats. 

I'm now looking at now adding bricks that are placed on top of the heat mats.  Looks like it may have some possibility. It seems that some of the heat is dissipated through the sides and the temperature is more constant. Calvin made a good suggestions about using a timer and the bricks may help hold some of the heat between on periods. There is an old camping trick where you heat a large rock in the fire and wrap it in newspaper and place it at the end of your sleeping bag on winter camping trips.

Would like to add some heat.  I know Michael, from this forum, uses an unused basement closet with a room heater (one of those oil filled radiator shaped space heaters) on low.  He was getting some good results. 

My problem was too MUCH heat.

Historically here, in many threads dating back years, most folks have discouraged the use of hearing mats. It is possible to have good experience, but it seems the bad typically outweigh the good by a fair margin.

I had good results using a heat mat last season. I rooted my cuttings in a shoe box type fill with spaghnum moss.  The shoe box is not in direct contact with the heat mat, it is raised about 3" above the heat mat. I placed the heat mat in an aquarium and use it like a green house. The cover is just a garbage bag with an air gap of about 2".

really thought about heating mat for long time. but found that near my computer at home in the corner of my study stays at constant 80 degrees all year around. i keep my baggies there all year around. no problem rooting. then they go into a plastic bin that i sanitize after each rooting on the floor. that place is always around 70-80 degrees. so indoor rooting is no big issue. i guess keeping my home computer on all the time has its benefits.

If it makes you feel any better, I dried out some nice roots on one of my cuttings about 2 weeks ago too.  I had placed the zip lock bag on top of my fluorescent shop light housing for added heat, and when I noticed how much humidity it was producing, I opened the bag to air it out for a few hours.  Well I had forgotten about it and after about 10 hours, the roots had turned black and shriveled up.  Good news is that the cutting rebounded and made new roots.  I noticed this morning actually.  These babies are determined!
So what I learned is not to mess with success.  I'm just keeping the cuttings on a shelf at room temperature and let them root when they're ready.  Very low maintenance, as the cuttings remains at a constant temp (65°f - 70°f).  It can take 7-30 days for cuttings to take root this way, but all 24 cuttings I attempted to root, did so!

Thanks for sharing your story.  Sounds as if this is something that others have experienced. I'm hoping that my figs will come back too and that the time spent at 100 degrees was short enough that the damage was minimal.  

I just raised the lower end of our thermostat to 65.

If the heat mat had a built in or adapted thermostat you would be set. I have an old heating mat from a water bed. Over 20 years old and used off and on for various seedlings. Hasn't failed me yet. I haven't used it for figs yet. If I did I'd place the sensor in the rooting medium.

65º is plenty warm enough to root a cutting.  Fig trees root during winter, I've pulled my pots during dormancy in the garage and found spaghetti of new, white roots.  I'd say, "don't get too hung up on temps".

I used heating mats on a timer (30min on/30 min off) and put them under my plastic bin a few times in rooting trials to warm the temps in the closed bin - the bin had a spacer on its floor (no direct contact with heat) similar to what Jon recommends in his Growing Tips area of figs4fun.com, like this:

Oh - and I should add - I don't remember actualy seeing any significant difference in rooting.  The only thing using heat like this did was make me feel like I was doing "everything I could".  The cuttings apparently could've cared less.  Again - classic example of humans "trying too hard" and "caring too much" about rooting what is, essentially, a glorified weed.

satellitehead,
Thank you! I kept reading that cutting rooted better at 70 degrees and above. What I was doing was working but thought that maybe I was missing something.  Maybe the roots would develop faster and stronger with heat. 

I've had a somewhat higher % of cuttings root at slightly cooler temperatures (in the 65 to 75* range) than when the temperatures get too much into the 80s. And higher than that mold more easily moves in.

I live in a mediterranean climate and figure figs originating in similar climates should root well in our natural temperature range. In other words, I believe my figs are smarter than I am. ;)