since they have two rather short growth spurts per year ... i wonder how you would shear them.. when they finally got to the height you wanted ...

you are thinking way outside the box ... and im thinking your are on the edge of discovering something new ... or finding out why a search engine cant find anything specific ....

https://www.google.com/search?q=picea+glauca+conica+hedge&site=webhp&source=lnms&sa=X&ved=0ahUKEwjK6JSJ6Z_VAhXh3YMKHcbNAtEQ_AUICSgA&biw=957&bih=746&dpr=0.9

but this makes me think .. how do you define hedge .. i think of boxwood or privet sheared twice a season .. maybe you dont mean that ...

ken

Very interesting idea. As Ken says, original and different. If you do it, please document with photos!

I think the odds of having this turn out as you hope are low. I've never tried it, but they are very prone to winter burn, which a hedge would only amplify. I'd go with Tsuga, which can be regularly pruned into a dense hedge.

Hedge as distinct from individual plants in a row https://www.google.ca/search?q=hedge&rls=com.microsoft:en-CA:IE-Address&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjwr8n89J_VAhWFyoMKHZDVC6gQ_AUICigB&biw=1304&bih=638

Around here, DAS winter burns disappear (get grown over) some time in June, but yeah, will copious watering in late fall prevent/minimize winter burn?

Nothing else will have the 'green velvet' look when viewing from a house window.

with the very small spring growth ... i dont know how they will grow together.. to blur the look of individual plants .. and the second flush wont be much more ...

but go for it ...

ken

Good luck. The plants used in hedges generally have fairly dense foliage throughout. This is not the case with DAS.

DAS has actually VERY dense foliage, much more dense than say arborvitae, a common hedge plant. DAS foliage is so dense that there are air flow issues > mites > often given advice of spraying with water jets to dislodge the mites.

In my cold zone, mites are usually not that big of an issue for specimen plantings, but a hedge would make the air flow issue worse, hence my thoughts of removing half of the DAS hedge trees on the opposite side of the viewing side to make the hedge airy, see my OP.

The very dense foliage of DAS is what gives it the 'green velvet' look and makes topiaries look smooth, even from close by.

OK. Im referring to the interior of DAS. I havent looked lately, but as I recall its mostly "dead/brown looking stuff"(some branches and needles). You may have a window of some years where it looks decent but I dont see it holding its nice looks over the long run. I dont know if you plan on topping them, but just cutting out half the tree does not seem conducive to a healthy tree(might be possible though), especially a DAS which are finicky to begin with (out of 10+, Im thinking Ill be lucky to get one specimen in 20+ years, and that is one of my goals as I really like large and "flawless" DAS). Not trying to be pessimistic, I just think you are fighting MaNa, and MaNa usually wins that battle. Cheers and by all means just my 0.02. I do like the idea and I am battling MaNa on my entire 2 acres as it is too wet for conifers so by all means try it out.

All old hedges have dead interiors, but it does not matter to the health of the hedge. I had an arborvitae hedge at my previous property that I let grow tall and wide with lots and lots of dead matter inside (that is impossible to remove).

If I remove the back side, that would allow for removing dead matter making the hedge more airy which should be even better.

And yes, as the OP says, I intend to keep the DAS hedge short at 4'-'5 for ease of maintenance.

Have you really grown 10+ DASs? I have just 1 which is moreover a topiary and it has been easy to maintain its good looks.

This quote from Wikipedia (scroll down the page) is relevant to the winter burn issue of DAS:

"Many nursery managers were long reluctant to apply nitrogenous fertilizers late in the growing season, for fear of increased danger of frost damage to succulent tissues. A presentation at the North American Forest Tree Nursery Soils Workshop at Syracuse in 1980 provided strong contrary evidence: Bob Eastman, President of the Western Maine Forest Nursery Co. stated that for 15 years he has been successful in avoiding winter “burn” to Norway spruce and white spruce in his nursery operation by fertilizing with 50-80 lb/ac (56–90 kg/ha) nitrogen in September, whereas previously winter burn had been experienced annually, often severely. Eastman also stated that the overwintering storage capacity of stock thus treated was much improved (Eastman 1980)."

I may want to try that to the DAS I have, hope it will not make a big issue out of a minor one, LOL