How did this work, or not?  I've been researching calcined clay and guess where I landed?  Right back at f4f lol.  

Seems for varieties that are said to be hard to root due to excess moisture, it might be just the thing.

I add it to every mix ( Promix + compost), I like it a lot. No side effects, creates an airy mix easily and cheaply.

Did some detective work as a comparison of two clay type absorbents.  

Oil Dry brand from Walmart $4.22 for 25 pounds.

 

Versus...

Safe T Sorb from Tractor Supply $6.29 for 40 pounds.

 

Both bags were sifted dry through a standard window screen and the result is seen in two 5 gallon buckets...

 

Overall, the Safe T Sorb was much more dusty and judge for yourself on the volume comparison of what would not go through the window screen.

The next two photo's showing particle size comparison.  Even though Oil Dry seems to have lost less by screening, the overall particle size is smaller and more uniform than Safe T Sorb, which has larger particles.

 

 

Both are a type of Montmorillonite clay.  Oil Dry states "Bentonite (Calcium Montmorillonite type" while Safe T Sorb states "Calcined Montmorillonite clay".  I'm not scientific enough to know the difference if there is one.

Both seem equally durable to me when wet and rubbed between the fingers, remaining intact, comparing that to clay kitty litter I tested yesterday that turned to mush fairly easily

If both serve the intended purpose equally well, I have to say the oil dry is a better buy, based on what usable portion doesn't fall through the window screen.

If larger particle size makes a notable difference then Safe T Sorb might be worth the losses resulted from screening.

I'm particularly interested if anyone has had success in rooting cuttings in 100% of either and continued with fertigation of some sort?  That's what I'm about to try unless somebody talks me out of it with a bad report.

Charlie,

Thanks for a nice scientific report :)

I tried to root and keep the cuttings in a shoe box with a coco+Napa dry until the roots were about 1.5-2" long before potting them up.
The cuttings really liked the mix (the lid was closed most of the time).
The mix in the pots had about 15% of the Napa grains. It worked out quite well to keep the moisture more or less even ( with the mulch on top)

Greg mentioned a hydrocarbon odor coming from the NAPA floor dry product and that Calcined Clay products wouldn't have that issue.  The Safe T Sorb most definitely has a hydrocarbon odor when saturated, similar to kerosene.  I don't really have a way to burn it off and am afraid to use it.

The Oil Dry product has no offensive odors I can detect when wet.  I'm soaking some of it now in a cloth pot, set inside a 2.5 gallon glass jug with a weak fertigation solution.

 

I really don't understand the need for this floor dry. What is the goal here?

Ahhhhhhh got it#

It holds water but also creates air spaces, which should be ideal for rooting figs.

I am just a big believer in cocoa coir. My strike rate is much better this year.