I can't figure out how to embed youtube with a starting time so it begins at 12 minutes and 23 seconds

I think what you are referring to is the pots in standing water.  I too wouldn't have thought that would work. I thought the roots would get water-logged.

Looks like the black madeira made a nice comeback

My guess is that if a fig had been in a container for a while without the water tray (and thus had a lot of roots on the bottom of the pot) and was then placed in a water tray the outcome might not been too good.  However, if you pot up a fig to a large container and place it in a water tray then the roots will grow down to the level of moisture they need and also adapt to the moisture conditions.  Figs growing in SIPs have lots of roots growing right into the water and they do very well.  Adaptation seems to be important.  Another issue with his set up, or a SIP, is that you don't want to use soil that wicks and holds lots of water.

My understanding is that the problem for roots results not from water per se but from anoxia (low oxygen) and possibly also a proliferation of bacteria that prefer anaerobic conditions, such as you'd get when fermenting vegetables.  

The water in the reservoir of a SIP is changed frequently.  It probably enters the SIP with some decent amount of dissolved oxygen and is replaced within a day or two by new, well oxygenated water.  So roots in the reservoir probably don't experience anoxia. 

In contrast, the potting medium can get saturated with water that is relatively stagnant.  Oxygen can be depleted and anaerobic bacteria can pickle the roots.  The art/science of creating an optimal potting medium for a SIP is to include enough fine, absorptive material so that water is wicked upward and outward but also enough coarse, non-absorptive material so that adequate oxygen is also maintained.  

Yes, you want soil that wicks some water but not a lot of water - so you need a happy medium.  As far as the water being stagnant I was thinking it would be similar for the trays in the video as what you would have in an internal reservoir of a SIP.  You might expect the water in the trays being out in the breeze could be even more oxygenated than that in a SIP.  At any rate, the figs in the video are doing well so proof is in the pudding.

http://www.bananas.org/f311/discussion-bananas-grown-water-14217.html

I read somewhere figs send deep and extensive roots to find underground waters/creek to combat dry seasons, so its roots can and will sit in those water to help the plant survive.

Figs eventually grow into SIP reservoir without harm is another proof of the roots' adaptive ways to sitting water.

Having said that, I had 2 figs drop all leaves because I watered them 1 day too soon. (They did bounce back)

Hi,
It will work in the dry summer but when comes Fall, he might run into a lot of problems.
Look at the Peter's honey - she is screaming: "Help I'm drowning" .
I only leave water that the tree can use within 4 days. If there is some remaining water after 4 days, I'll give less water.
Leaving such standing water is not advised, for mosquitoes will develop in there.
What I do:
When the weather is hot, I leave a saucer under the pots and I leave water in the saucer. Honestly the water won't last long in there as the trees will use it.
Sometimes in the summer, I have to fill the saucers twice.
With rainy weather and when the weather freshens, I remove the saucers.
This week, I removed a pot from inside a bucket -called that a saucer- because I saw too much water in the bucket.
That pot has been in the bucket the whole summer.

Thanks for adding this topic KK.
It's not something I do with my pots now but it reminded me that a few years ago, I grew a mature white marseilles in a pot inside a large bowl. I kept it watered so that there was always some water in the bottom of the bowl. Funnily enough at the time this was done more to deter ants than for growing requirements.
I don't remember that it was an exceptional summer but I had my best ever crop from it that year, 200 plus figs with 50 or so breba and 150 plus main.
Coincidence perhaps, but when I came to root prune in the winter, there was quite a mat of roots through the drainage holes which would have been sitting happily in water for much of, if not all summer. So at least for mature fig trees the lesson may be that as it's difficult to judge exactly the right amount, more than enough water is better than not enough.
I'm thinking its worth revisiting this idea.

I am itching to try this out but worry it may kill my young fig trees. :(

My fig growing went from completely mediocre to stellar when I placed all of my fig trees in wicking buckets (5gal). I think there is already info on the forum, but basically you drill a 3/8" hole 3" from the bottom. Put a landscape fabric wrapped 4" drain pipe across the bottom to the drilled hole, and then put a vertical 1" PVC pipe through the drain pipe opposite from the hole. You water through the drain pipe until the water comes out the 3/8" hole. The top of the bucket is covered with landscape fabric and the 3/8" drain hole is covered with screen to prevent mosquitoes. My trees are just over a year old and all but one gave me figs this year. This spring they were only about 12"-15" tall! They just exploded! I will do the same thing as I upsize to larger pots. Will probably put them on a drip sysyem as well.

It is so fascinating to read about SIPs that have actually worked. Perhaps they work in really hot areas. 
I bought around 50 SIPs. And planted several plants in them: raspberries, newly grafted apple trees, currants, grapes and of course figs. 
The raspberries and currants survived and did well. The grapes and apples died. The figs just sat there and sulked. I noticed that roots had rotted in the pots. When I realized this and removed the plants from SIPs and used conventional pots with lots of drainage, they took off!

Oh, one of these was a KK BM that I got from one of KK's auctions. It lost all its leaves sitting in a SIP. When I took it out of the SIP, it put on over a foot of growth in a month with tons of new leaves and branches.

I've actually used the "wicking bucket" method Kenny describes (post #14) for several years here in Zone 6 and it works spectacularly.  It's the best way I've found to go from cutting to a fruiting tree in a single season.  I've observed what I believe are 2 separate types of roots on fig trees: 1) fine, fibrous upper roots that grow horizontally and 2) long, much stronger roots that grow downward in search of water.  I tend to believe that if the stem and fibrous roots are kept well-drained, the tree thrives even when the long roots are totally submerged as they would be in this set-up. 

Here's a photo of my N600M roots at the end of its 1st season.  Notice the size of the roots at the bottom of the root ball vs the top.  Some of those bottom roots were more than 6 ft long!  Fwiw, there's no need to wrap the drainage pipe with landscape cloth; roots don't migrate into the pipe. 

 

Mimi, that looks great!

How deep is the trunk? What kind of mix do you use for that SIP? And in your growing seasons, do you get enough rain?

I am trying to figure out how to build SIP for SoCal, which is dry and hot in summer. Some people say the roots go to the lower half of the pot, instead of top here because of the dry weather.