Guys, I can only give you information of my results. If I may, let me add a bit more information. When you have an idea about switching to self-watering pots please consider this:
1. The final size of that tree's container
2. The thickness of that container
3. The movement of that container with a tree inside
4. Drainage/overflow.
Here is why!
Coop and Pete hit the nail on the head with their comments so please consider them. Some of us don't have the luxury to drive and visit Bill. I've email and talked to Bill on the phone several time with questions. He's been a wealth of knowledge to me! Here is what I've learned growing figs over year in SWPs.
Consider or think about your goal switching to this method!
My goal was to reduce touching the roots of my trees over time. My second goal was making sure my trees got enough water just to stay moist, not wet! My third goal was to find a large enough pot THAT WOULD LAST AT LEAST 15+ years. Why consider a pot’s age? Because if you take those cheap 6 or 7 dollar colorful plastic tubs from Lowes or HD with the rope for handles, they will only last you 2 years or less! When you add 3 or 5 gallons of water in one of those tubs, plus dirt, plus the tree and plus the weather, the pot will complete fall apart in no time. I used those container 7yrs ago. Every one cracked and just fell apart in less than 24 mos! You waste time and money once again playing around with those pots. So, don’t go the cheap route. Trust me.
Consider how you will repot and move your tree!
A fig tree grows excellent in SWP for 3 to 4 years. Now, when the time comes, you have to repot the tree. Plan ahead. In other words, don’t build a large boat in your garage and start thinking about how to get it out after you finish it! You have to consider how you plan on moving the tree before you repot it. Bill created an excellent tool for moving his trees around. I like his dolly! I have all the tools to make his tree lift but I’m not sure it will work with my 27g containers. I may end up buying a huge plant dolly for time sake.
Consider container life!
I use 4 types of pots; Bill’s pots, half 55g plastic barrels, Big Lots fluted pots (I got them years ago when they were cheap, today they’re 14 bucks a pop), and Walmart SWP. The Walmart pots are great but they are not that deep and are very thin. But it does a good job until the tree is fully grown. And mosquitos like to lay their eggs in them due to the bottom hole opening. So, if you have a lot of trees like me, you could have a mosquito problem unless you use dunks and I do. The 55g food grade barrels last longer than 20 years and they are larger than Bill’s pots.
Consider container size!
When I say size, I’m talking depth and circumference. Why? B/c you have to consider room in the bottom of a container for the water reservoir which is about 3 to 4 inches. My trees have to have at least 16 inches of depth or more. Those plastic whiskey barrel looking pots at Lowes look great. But in my honest opinion, they are not deep enough. My Big Lot pots work fine but the bottom is not sealed. Since I already have them, I found a way to seal them and my trees grow well in them. You should see my LSU Black in one of these pots! The base of the tree is huge!
I tried using thick plastic to cover up the top of my trees like Bill does. I stopped doing that. Why? In my opinion, it’s just too much maintenance. Today, I just lay a thick weed guard and burlap on top and add mini pine bark nuggets. It works well of me and it look better. When it rains, I don’t water them. I let mother nature do her thing! If the tree gets too much water, it will come out of overflow spout. And make sure you pot your tree 3 inches above the rim of the pot! Otherwise you will wish you did months later when the tree completely settles.
Hope my tips help someone and save you time and money!