Stonehenge Skinny is too new to have any sort of body of growth info available. It is not even on the retail marketplace until 2021!

But having said that, ANY yew is extremely amenable to pruning and even quite hard/severe pruning. I think it may be overly optimistic to keep a Hicksii to an 8" width but IMO, the very narrow forms (like Beanpole or Skinny) require almost no pruning at all so not sure how "sharp" an edge you can maintain.

how much instant gratification do you wish???

its much easier to start rather small.. and train them from the get go ...

as compared to starting with a 3 or 4 foot plant .. and then trying to force your goals on it ...

ken

and when they say "needs no pruning " that would be for a round shape

for you , I would start at an early age ...lightly

for rectangle

ron

Not understanding what

12"W x 8"D x 7'H

is supposed to be describing. Usually tree dimensions are given as height x crown circumference x average crown spread. Whereas you seem to be saying width x diameter x height - assuming this was your intention what are the first two figures supposed to be referring to, that are not the same thing?

Otherwise as mentioned if the 'Stonehenge Skinny' hasn't been grown long enough for a fully developed example to exist then it is a pretty safe bet that it will in time grow much larger than commercial depictions you have seen may be indicating.

With those narrow dimensions, I think you should consider a sculpture.

...or maybe look into Taxus baccata Stricta or similar. But those, too, would be tough to keep at those dimensions.

tj

@Embothrium, I see now how this is confusing! What I mean by D is depth, to describe the desired rectangular cross-section. As for growth rate, you are probably right: perhaps if I acquire a somewhat older 'Stonehenge Skinny', it will make its way to prune-able dimensions in a more reasonable time.

@plantkiller_il_5, this makes sense. If I get a tree that hasn't reached much past 8", it stands to reason I could keep it this way.

@fraker True, a sculpture would solve the design issues instantly, of course. But I think it will be more fun to shape my own sculpture from a tree!

@ken_adrian Adrian MI cold Z5 I suppose that absolute instant gratification is not a realistic goal. I am aiming for 7-ish feet in height (so I can stand in its shade occasionally while gardening on a hot day), and how close to that height I start out with will be mostly a matter of price. But as @Embothrium and @plantkiller_il_5 suggested, starting with something narrower than needed, and being patient on that front in terms of when to impose shape, may indeed be the wisest move.

Thanks for the recommendation; I'll check them out.