Willow root containment

Hi all this is (willowgirl) this is my first thread, hopefully it's the correct section? If not can you please advise me.

 My question regards live willow fencing, the latin name is "Salix Viminalis" usually used for baskets etc, & although a native variety I am a tad worried regarding the rooting spread & if there's a cheap n cheerful or common sense method of containing the root system I really only want the plants to be 5'high in a overlapping arch form to give privacy from my noisy neighbours, but the start of the fence is quite close to the rear of my house (6').

Just to many horror stories about the aggressive roots etc, I've had a real good search online & found a few ideas on (Pintrest) suggesting to use empty 6pint milk container with the top cut off for other plants would this form of containment work for the above willow plant? or if not can anyone offer a similar simple way to resolve the issue without digging trenches, any help would be very gratefully received.

regards all willowgirl xXx