Root Restricting Fabric for Later Transplanting - Ideas?

I have some hedge plants that are "ready" for planting. But the site is not yet ready (and won't be for a year, maybe two).

I was thinking that rather than trying to bring them on in pots, which is never as good as planting them out, whether I could plant them in "troughs". I don't really want to use "balcony troughs", although I suppose that would do.

What I was thinking was to dig a trench, line with "Root Restricting Fabric", fill in with compost / manure / soil, and then plant them "as if a hedge", and then transplant them (in 3' or 6' lengths) at some future point. I figure they will grow much better for being "in the ground" (capillary action to get moisture from below, and sides, as well as any irrigation). My thought was to restrict them into lengths that are something between 3' and 6' (not sure how heavy they would be to transplant, but I reckon that 6' would be a better self contained unit than 3', assuming it won't be too heavy to lift - I could do some sums for how many Litres of compost that would be, and thus estimate the weight).

I did find some clever fabric (made by ICI, or du Pont, or somesuch) a while ago - it let the roots grow through, but constricted them such that they didn';t form a significant root structure the far side of the fabric, and thus they survived transplanting really well ... but I can't find any indication that that fabric is still available.

It would help if the fabric / containers / whatever wasn't hugely expensive, but I'm open to ideas

 

Aren't trees supposed to grow better, and form a more fibrous root system, if transplanted a couple of times.
If so a couple of years before moving to a permanent position shouldn't be a problem as long as they are moved at the correct time of the year.

 

Good point, I often see (bare rooted) hedging plants sold as having been "transplanted X times". Although I suppose anything sold pot-grown won't have been transplanted.

I'm rather wanting mine to press on beyond [what I suspect is] that point though - they are 3' already, and ideally would be 5' - 6' when they are planted out, hence I was thinking of treating them as if container grown.