“What is a good upright juniper, or other narrow conifer, to plant that stays nice and narrow and tight so snow doesn’t bend the branches down and damage them? My planting area only gets partial sun and is very dry for much of the year. I tried Skyrocket junipers, but they broke under the weight of the snow.” Question from Sharon of Westminster, Colorado.
Answer: There are quite a few evergreens that can take snow load. The best are natives to your region, but there are also some cultivated, non-natives to consider.
Narrow stature can reduce snow load, but limb flexibility is even more important. Trees with unrelenting, stiff branches suffer the most breakage, while those with flexible branches bend under snow and pop back when the weight is gone. Often, the snow will slip off as the branches bend. Your native limber pine (Pinus flexus) is named for this trait.
Thinking along these lines, I would choose evergreens with good strength, bendy branches, some drought tolerance, and the ability to survive in lower light as young trees. Native selections will likely perform the best. Good options do not have to be linear.
Colorado Native Snow-Resistant Evergreens
- The superlinear fastigiate Douglas fir, Pseudotsuga menziesii ‘Fastigiata’, is hardy to Zone 5 and has moderate drought tolerance.
- Rocky Mountain cedar (Juniperus scopulorum), grows to 30 feet and can withstand some understory (partial shade) conditions as well as drought.
- The Limber pine (Pinus flexus) will reach 65 feet, withstand some drought, and take lower light until it outgrows surrounding trees.
- The columnar lodgepole pine (Pinus contorta var. latifolia ‘Fastigiata’) and tall, super-tough Ponderosa pine (Pinus ponderosa) are two more options tolerant of the conditions you mention.
Non-Native Snow-Resistant Evergreen Options
- Prairie Statesman® Swiss stone pine (Pinus cembra ‘Herman’): This alpine tree may not be native, but it is narrow, upright and stands up to snow. It is also drought-tolerant, withstands very cold winters, and reaches 30 feet high and 10 feet wide. Its bright green needles are very fine.
- Green Arrow Alaska Cedar (Chamaecyparis nootkatensis ‘Green Arrow’): This is about as narrow as you can get. No snow could hang onto these branches. Green Arrow is very hardy, reaches 20 feet high and 2 feet wide. These look best planted in a group.
- Hetz’s Chinese juniper (Juniperus chinensis ‘Hetzii Columnaris’ or ‘Columnaris’): This Chinese juniper is pyramidal, narrow, relatively compact (reaching 15 feet or taller) and provides a good windbreak for very cold areas to USDA Hardiness Zone 4.
- Serbian spruce (Picea omorika, Zone 4). There are many tall, narrow varieties adapted to high snowfall, but the tree only has moderate drought tolerance.
I encourage you to search out more varieties via the ever-useful Morton Arboretum’s Tree Database.)
Happy conifer growing!
Black Gold Horticulturist