Edible Fig you can live with,plus they are tasty. Easy to prune. Planting any thing small close to any tree is always going to be one sided in the tree's favor. A raised bed with heavy duty weed cloth under it to stop larger root invasion could work.

Other then that..normal sized landscape plants have no problems with Ficus carica.

I once asked that question about edible fig and whether their massive root system would kill other plants. I have roses, crinum, some annuals about 4 ft from the trunk and they have done well. It was quite a chore to dig holes for other plants but curiously, none have suffered. I agree with you, that root systems is like nothing else I've seen. Best of luck in your garden.

Redondo Beach.

The fig produces profusely. Unfortunately neither we nor our neighbor get any. There are some happy squirrels in our area though!

How deep would a barrier need to be?

As a landscaper faced with tree roots crowding out small plants' beds(You've not seen anything so invasive as Douglas Fir tree roots literally honeycombing through flower beds!), my solution for my customers is to dig down about 20 inches for the flower bed, remove all the roots, line the bottom and sides with two layers of 4-6 mil black plastic with the bottom slightly higher at one end sloping to the corner farthest from the tree in question and in that far corner cut cut small holes through the plastic with a course rock-filled French Drain pit lower that the bottom of the flower bed to catch excess water. The plastic I leave a few inches above the surface to discourage even the surface roots growing through surface decaying plant liter.

This lasts many years if the plastic is not punctured.

I had a large fig in my backyard. It ran 6" diameter roots 40' to orange trees. It ran large roots under the foundation of a retaining wall and then was lifting the concrete around my pool on the OTHER side of the retaining wall.

That fence needs to be replaced with a block wall with the 2' deep and 2' wide foundation required in CA. Even then, the fig will start destroying that in 20 years. Figs are a nightmare.

Are you talking about the deciduous edible Fig or those monster evergreen Ficus Greg?

Large edible Fig roots almost never show up at the surface. Lift concrete? Ficus carica? Maybe a huge 75 year old edible fig with a tight collar of pavement..but..the Mediterranean climate Fig roots deep because they are from a dry climate. A cool dry climate.

Completely depends on location. The fig, as all trees, grows according to the environment. The native climate means little for a tree where the climate is different. as in a back yard where it gets plenty of water and nutrients. Hope this helps explain the situation of this topic.

"Are you talking about the deciduous edible Fig or those monster evergreen Ficus Greg?"

Deciduous edible fig. I can't tell you the variety because it was there when I bought the house. It produced good tasting black figs. My backyard was a commercial orange grove until the houses were built in 1970 and that area was cut and a retaining wall added. I would guess from the location that it was small when planted because you wouldn't plant a large plant that close to a retaining wall. It looked to be about the size of the one in the OP's picture when I bought the house in 1998 when it could have been a maximum of 28 years old.

I cut it back to tear it out in 2013 and spent the next 3 years trying to get rid of it. You can see the stump between the palm fronds behind the retaining wall. Also the surface roots going laterally and up the hill, the damaged retaining wall and lifting concrete at the pool edge below it. It was strangling several 50+ year old orange trees that are behind it on the flat area at the extreme rear.

Oh-ok I see. Just as I surmised- old plant had a new wall put right up against it. Plus with a pool...no way a Fig could stay there dropping in overripe bombs with a cloud of fruitflys ( I remember that!) into the pool.

I tell you Greg,you have a great spot to grow some choice large succulents behind the pool. Some impressive plants. All would do fine on a drip.

I have no advice about the fig, but loved your post because you admit you planted a weed you liked the looks of!

All that hassle and no fruit? Geeez.

Plant your own favorite variety of fig and get rid of the squirrels.

I actually have a similar situation right now. Neighbor planted a tiny Italian Honey fig 2 ft. away from the fence - on the opposite side of my Lisbon lemon. Then she sold the house. Years later, the fig is overtaking the area. I am yanking roots when i can - they go for 30 ft.+ !

The new neighbors are clueless about their fruit trees and have given up trying to harvest anything - - - feeding all the vermin and pests - like squirrels.

Sooo my next action is to yank the struggling Lisbon (its ok, i have 3 other lemon trees) and plant a more ferocious variety of fig - and water at the fence to ensure the roots go in the neighbor's direction.

Let us know what you ultimately choose to do - - - and good luck!