Which tree for the border of a new terrace?

Hi everybody and congrats for the fantastic forum. Here is Paolo, beginner permaculturist from Italy. I recently dug a few terraces in my steep field and blocked them with a barrier made of wooden poles. Altough stable now, it will eventually rotten and loose strenght so I need some strong roots near the wall to help hold the whole thing up. At first I was only thinking about a small hedgerow, something out of rosemary and sage bushes. But now I realize I need some bigger roots, so the answer is trees (also more appropriate to the food forest concept I'd like to develop here). Ideally this plant should: grow its roots rapidly, give fruits and enjoy the sun (my slope faces south west and in summer is burning hot). So the question is: which tree do you suggest?

Fig!

Your challenge is to find something that is vigorous enough to hold your terrace, hopefully something productive in multiple ways, and yet isn't too bad with invasive and moisture seeking roots competing with everything else you might want to grow on the terraces themselves.... Ideally too it would be something that can root from cuttings, so that roots might grow out of the stem into the vertical face of the terrace behind as the pole-work decays, and that is amenable to coppicing, hedging by hacking halfway through and bending, etc. In my mind only one potential rises to the top of the list of possibilites....mulberry. Many types are vigorous and hardy, tolerant of drought once established, amenable to coppice, able to root from cuttings, and of course producing fruit and (for goats and such like) edible forage....

How about some perennial grass. They will have deep roots good for holding soil. You can come and cut them for mulch, animal feed, Compost material. They grow right back and sometime soon again you can cut them again and so on for a very long time. They propagate very easily by dividing up the clumps. Sometimes giving you a few hundred new plants from one mature plant. They provide good habitat, ground cover from the brutal sun, drought tolerant. See what you can find locally.

Alder Burns wrote:Your challenge is to find something that is vigorous enough to hold your terrace, hopefully something productive in multiple ways, and yet isn't too bad with invasive and moisture seeking roots competing with everything else you might want to grow on the terraces themselves.... Ideally too it would be something that can root from cuttings, so that roots might grow out of the stem into the vertical face of the terrace behind as the pole-work decays, and that is amenable to coppicing, hedging by hacking halfway through and bending, etc. In my mind only one potential rises to the top of the list of possibilites....mulberry. Many types are vigorous and hardy, tolerant of drought once established, amenable to coppice, able to root from cuttings, and of course producing fruit and (for goats and such like) edible forage....

& fig!!!

Thanks for the quick answers and the ideas!

Both bushes and grasses are going to be planted in the hedgerow that will limit the terraces, of course. Clover, iris, rosmary among others, and yes, mulberry, great! My question was more focused on trees tho, that is to say on a taller layer of the food forest scheme. Fig sounds interesting (my neighbour has a very vigorous one just next to my terraces), altough i don't know about the speed of roots growth which is really a crucial point here. Keep shooting folks, thanks!

Of course, it will vary with your local climate, soils, yada-yada. What we do here is grasses, legumes, kale, rape, raspberries, blackberries, blueberries, apples, pears and beechnuts. They all produce food for us and the livestock as well as holding the shape of the soil. I run fencing at the tops and bottoms of the terrace slops to keep critters from breaking down the terraces with foot traffic which would cause ditches that water would flash flood through and rip out my berms.

http://sugarmtnfarm.com/2012/10/01/perfect-pear/

http://sugarmtnfarm.com/2012/04/19/fencing-2/

Another tree we incidentally have a lot of along the terraces is aspen. They are wild growing, come up well from the regen and are good fodder. Later when I want to plant fruit trees there I just start thinning out the aspen.

I would go for some fast growing what I would cut down later. Meanwhile you grow something slow growing which bears fruit.
Fast growing is bamboo but it does not like very much the sun. Eleaegnus species like the sun and paulownia grows very fast and it is a soil improver.
Acacias would be suitable too. Figs don't really grow fast. Peaches grow fast but they need plenty of fertilizer.