This is something I've wondered about - do you re-cut the ends of cuttings for a fresh surface, or do 'aged' ends root better?

I cut many cuttings in half - wish I had kept decent notes. I sure will next year.

I don't rec-cut the ends, but am no expert.  Aren't the ends supposed to callous and that is supposed to aid in rooting?  I don't understand about callousing and maybe someone can explain it.

I also heard about the callousing and would like to know more. I know I cut many of mine and some into pieces. I also did not take good notes.

I've just been doing some reading and it seems adventitious roots (those formed on cuttings from stem tissue) can arise from several places/tissues in a stem.

Some species of plants that are easy to root have what are known as latent root initials already in their stems. These are areas of cells that will begin dividing when/if they are needed - as in when a branch is removed from a tree. I suspect figs have these perhaps beneath nodes.

There are other plants where these (latent) root initials are visible on the external stems as little nubs - examples are Philodendron, tomato, Coleus. (The use of the terms root 'primordia' and 'initials', (even internal 'callus') over-lap and usage seems to depend on which text you are reading.)

 Callus tissue is formed when relatively unspecialized cells resume cell division and a mass or lump of tissue is formed. These can arise from several places within a stem, but apparently mainly from the food conducting tissues (phloem), cambium, ray cells, etc. When a stem is cut, in the correct circumstances callus formation can be seen at the cut as little bulges around the base. Sometimes in high humidity, also at the top of a cutting.

While some species form roots from callus, it is not required for adventitious root formation. And some plants form callus at a basal cut, but new roots actually develop on the stem above the callus. If you look at photos of roots emerging from fig cuttings, they often are seen just above the bottom of the cutting (often just below a node, but sometimes scattered along internodes.)

Regardless of terminology, the process involves getting cells in a dormant cutting to begin actively dividing and eventually developing into roots. There seems to be much variety in root formation across the plant world. My guess is figs, which are generally easy to root, utilize more than one anatomical avenue. Just my guess.

As to whether a cutting should be freshly cut prior to rooting, I don't know. There are many species of plants that root better when the stem has been wounded (often with a razor blade slicing off a thin, 1 inch fillet at the base - sometimes on both sides of the stem).

This is general information and not necessarily fig specific. Much is unknown.

Callousing supposedly prevents uptake of disadvantageous things such as diseases.

Ever stuck a flower or celery in color water?

This is why I lay my cuttings down horizontally in a 1" trench in partial shade, cover them with loose topsoil (no perlite, no moss, just dirt), and one cutting will give 2 or 9 trees depending how long the cutting is.  Then, you have to sort out the roots when your orchard goes dormant!
Suzi

Callousing is a different story.  The end needs warmth, and people go out and buy electric blankets, and all kinds of stuff to keep warmth on the end.  But you could put the cuttings upside down in a hole 1/2" longer than the cutting in the sun.  After some time, you will see root initials, and then you have to put the whole thing right side up.  This seems like too much trouble to me!

Callus tissue is just a cluster of cells and does not need extra warmth to form. I've seen some on my current cuttings, and I've taken care to not allow them to get warm at all. Just unheated room temperature (mostly 55 to 75*F). Callus formation likely requires the same temperatures that is needed by root formation. :)

Your horizontal cuttings probably are forming callus too since you are providing the right environment for rooting, only you don't see it because they are covered by soil. Unless one is looking for it, it sort of blends in. As Jon said, it sometimes provides protection to a wounded surface and prevents entry of pathogens.

Whatever works. There are many successful ways to root figs.

Noss, I root some hard to root figs horizontal in pots through the winter outside. This year I received some unknown Italian types from another member and one of them only rooted this way for me. I routinely use this method as a carefree or hands off method with cuttings that I have plenty of. I use it as a sort of "if all else fails" method or should I say if I kill all the other ways I trying. I take a one gallon pot fill it half way full with my potting mix. I use a mix made from twenty five percent peat, twenty five percent sand, twenty five percent compost and twenty five percent pine bark fines that I have sent through my wood chipper. I add a very small amount of perlite and a small amount of lime. You want something that will hold a little water. I take a cutting with nodes on either end place it horizontal in the middle of the pot then cover with one and a half to two inches more of mix. Then water thoroughly. I place it next to my back fence so that they are shaded and let them be. I only re-water them when the mix pulls away from the inside of the pot. I only bring them into the garage if the temp is going to thirty two or below. In the picture below the two black pots were done this way. In fact they are one of the unknown Italian types.