Another plant list! This is based on a question that keeps popping up from members of my local horticultural society, as well as online. They’re looking for columnar conifers for their small urban gardens – and the clincher is, of course, that the trees have to be hardy enough for the Canadian Prairies. Bear in mind that in areas like Calgary, where we have drying winter winds, desiccation can be a major problem and may cause severe browning in conifers. Keep those trees consistently watered up through autumn and use mulch!
Columnar Conifers for Prairie Gardens
‘Moonglow’ Juniper – J. scopulorum ‘Moonglow’ – zone 3 – 16 feet tall and 8 feet spread
‘Wichita Blue’ Juniper – J. scopulorum ‘Wichita Blue’ – zone 3 – 12 feet tall and 8 feet spread
‘Cologreen’ Juniper – J. scopulorum ‘Cologreen’ – zone 3 – 13 feet tall and 5 feet spread
‘Medora’ Juniper – J. scopulorum ‘Medora’ – zone 3 – 10 feet tall and 3 feet spread
Columnar Blue Spruce – Picea pungens fastigiata – zone 2 – 20 feet tall and 5 feet spread
Columnar Norway Spruce – Picea abies ‘Cupressina’; ‘Christina’; ‘Pyramidalis’ – zone 4 – 18 feet tall and 5 feet spread
Columnar White Pine – Pinus strobus fastigiata – zone 3 – 30 feet tall and 8 feet spread
‘DeGroot Spire’ Cedar – Thuja occidentalis ‘DeGroot Spire’ – zone 3 – 12 feet tall and 2 feet spread
‘Skybound’ Cedar – T. occidentalis ‘Skybound’ – zone 2 – 16 feet tall and 5 feet spread
‘Brandon’ Cedar – T. occidentalis ‘Brandon’ – zone 3 – 13 feet tall and 5 feet spread
What are your favourite trees for small gardens? (They don’t have to be Prairie-hardy, nor do they have to be conifers!).
Flowery Prose 
I have found Cephalotaxus harringtonia ‘Fastigiata’ to be very useful, not least because it is shade tolerant. 🙂 Three youngsters are in my garden at the moment and will fill in some narrow but very open-to-the-neighbor’s-house-view gaps in between some mature conifers. None of the spaces get direct sun for more than a few hours a day, but they are doing really well and of course would be equally happy in more, or full, sun also. It matures at 8-10 ft tall but only 3-5 ft wide. Mine are about 2 ft tall so far, and less than 12″ wide so they are right on track of having the width be half (or slightly less) their height. 🙂
An extremely attractive tree – I can see why you like them! Seems that they are perfectly sited in your garden, and will fit well at their mature size. Always great to find something that works AND has great looks!