One method of growing figs in areas with cold winters is to keep them in containers but partially bury the containers in the ground during the growing season so that the roots can access the surrounding soil.  After the figs become dormant in the Fall the roots are cut and containers removed for storage.  For those of you who have experience doing this what is the optimal size of container?  Is 5 gallons enough or should it be more like 10 gallons?  Thanks!

For practical reason I have limited the container size to 7-gallons (body strength and safety of the back- even though I know about trolley use); though I have some plants in 5-gallon pots.

The practice of partial burying of pots, in addition to roots going out in search for nutrients and moisture in the soil outside the container, the practice helps relatively reduce the frequency of root pruning.
I make sure that the holes in the pots are on the side walls  and not on the bottom. It becomes difficult to dig out a pot if roots manage to to go out a hole at the bottom of the pot and more so when it is cold and rainy fall weather like in our location.

How large are the side holes?  I'll be doing this too.  Thanks

If you're strong and use a long lifting plate on your hand truck you can go as big as your strength.  Navid uses 65 Gal pots, others max out at 25 Gal.  DrivewayFarmer uses 5 gal because it's what he has.  A 10 gal pot will give you a lot more than double the amount of figs a 5 gal will assuming both get the same care.  But DrivewayFarmer will get a lot more out of his 5 gal pots than the average person will out of a 10 gal pot.  Knowledge, experience and hard work play a big role.

I thought drivewayfarmer grew his figs on the driveway :)

Bob
You wrote "A 10 gal pot will give you a lot more than double the amount of figs a 5 gal will " and that "DrivewayFarmer, with his experience, will get a lot more out of his 5 gal pots than the average person ".

So, for average experience person the good size pot, partially buried, may be about  (10+5/2)  ~ 7-gallon. That is what I can easily handle. Somehow it makes me feel better now.

Bob, I had been under the impression that the size shouldn't matter too much (once you get above 5-10 gallons) if the roots had access to the surrounding soil but maybe I'm wrong.  My one experience with doing this did not go well.  My VdB looked great in a ~ 7 gallon partially buried container.  However,  I decided to remove it from the soil before it was dormant because we were supposed to have a cold snap.  As soon as I removed it the leaves looked droopy then finally fell off.  The next spring (last season) I moved it to a larger pot (~ 20 gallons) and decided not to bury the pot.  It bore very little fruit all season and didn't look particularly happy all year.  So clearly you need to let the trees become dormant before taking them out but I was also wondering if others have found that the trees don't recover well to the shock of having a significant part of their root mass pruned off.  Hopefully my experience was a fluke.  Oh, and I would also like to hear about the optimal size of the holes on the side.

i put 1/2 '' holes every 2'' around the bottom  side of 5 gal containers. the trees seem to like that.

for me, 1/2 burying pots keeps them from overheating. i didn't get that many roots out, so there didn't seem much  shock when i moved them.

but, if you're in 7a, i don't understand why you don't plant inground. then you get maximum figs and minimum work.

Suzie, I will be trialing about 20 varieties and many of these will be planted in-ground.  Because I don't have a lot of space the plan is to give them around a 5 foot circle and keep them carefully pruned so that they don't get too large.  Then after about 3-4 years I'll keep the 1/3 or so that rise to the top in terms of performance.  There is one area though along the south side of my house that is a strip of soil between the brick wall of the house and an asphalt driveway.  It gets nearly full sun and would be a good microclimate for heat and sun-loving figs.  I'm a little squeamish about planting figs in the ground there because of worries about the foundation even though most people say it shouldn't be a problem.  So on the short term, while trialing varieties, I thought it might make the most sense to bury figs in containers there.

I use these Pro Cal pots which I purchase online from a place in Calif. and they have a sturdy lip for lifting. I realize you can not tell
much about them from the pic of this fifteen gal pot. I buried about thirty five , 3/4 of the pot in the ground last year. Most of the
pots were five to seven gal but I did have a few ten and fifteen gal also. This year most will be seven to fifteen gal pots.  I then mulch
heavily with pine straw. Once the roots get outside the pots the amount of water needed really decreases.

well, that sounds sensible. i just have a hard time picturing root damage to foundation in less than 50-60 years.

i guess we've done the same reading tho. the consensus says no damage. i know of one person who had a tree some 30 years old who had to
remove a fig because it grew big enow to damage the roof. he didn't mention foundation problems.

i won't plant next to the house this year, but i plan to the next year. i sure hope  that i get no damage. you may be wiser than i.

Mike, thanks for the tip - they look well built and I'm sure the lip is handy when they need to come out of the ground.

BTW, DrivewayFarmer uses 5 gal buckets, which are truly 5 Gal.  I didn't bury any of my pots but most of them had roots growing into the soil from side holes.  The plants are clever enough to figure it out.