Plant in a soil based compost

good morning Greenfields, acording to the RHS the fig is tolerant of a wide range of soils provided they are well drained, root restriction is necessary , however to prevent the tree becoming over-large,and vigorous at the expense of fruitfulness,either by planting in a container,or in a narrow border about one and a half to two feet wide,betwen a wall and a concreat path,the size of the container influences the eventual size of the tree, hope this is what you wanted to know. Good morning Drc,

Treat 'em mean! If you give them a rich compost and feed them, you will get a fantastic fig tree with masses of leaves and lots of stems, but very few fruit, as Cliffo says above.
On the other hand, I have never gone into root restriction, though as ours are planted next to a barn wall (south facing) the roots are restricted I guess anyway. We normally get good crops of figs on healthy trees. Pruning is important to maximise the crop.
Ours are in heavy clay and seem to like it.

Agreed, they have no special requirements for soil - you can restrict root size simply by judicious pruning, so doesn't have to be in a pot. It should be cut back hard during the dormant season every year anyway.

I have had a fig tree for years that didn't do much. Last year I got about 12 figs and fought the birds. I juice and was composting all the pulp two years ago and put it around the fig tree after it was compost. This tree went crazy. From a dead stick it grew great leaves and Tons of fruit. And then more fruit until it is in clusters. So your thinking wow great. But no. A lot of those figs are falling to the ground hard and not edible. And every once in a while I get one that I fight the birds for. I will take off some of the compost but what happened ?

Not sure - maybe you should post a new question in the questions section, preferably with photos.