White spruce or black spruce?

(Question)

Hi, I enquired about white spruce a few days ago. However, I based on the answer I got I suspect whether I got the name of the tree wrong. An arborist told me these trees in my neighbor’s backyard are white spruce and are what I need too, because they grow tall and narrow, can tolerate some shade, and grow fast. I attached a photo this time. Can you help me identify what they are? Are they white spruce at all? They are the trees I plan to grow along my back fence to form a tall hedge to block the view of the apartment buildings.
Thanks for your help!

(Answer)

Hello,

Thank you for your question to Toronto Master Gardeners. I believe that the tree you have in your picture is a white spruce, but it’s impossible to identify definitively from that photo. You will have to look at these finer points I describe below. I consulted Native Trees of Canada by R.C. Hosie, an excellent book and available in the Toronto Public Library.

White Spruce, Picea glauca – It’s quite tolerant of shade and retains its leaves and branches low on the trunk. The leaves are broad, needle-shaped and about 3/4″ long, stiff with blunt ends. The cones are about 2″ long, slender, cylindrical, with stiff, smooth-margined, often indented, roundish, close-fitting, light brown scales which spread almost at right angles on open cones. Twigs are usually without hairs, whitish-grey to yellowish.

Black Spruce, Picea mariana – In stands, it is without branches for most of it’s length. The needles are broad, needle-shaped and about 1/2″ long (noticeably shorter than those of the white spruce). The cones are smaller too – about 1″ long, egg-shaped, pointed, almost spherical when open. The scales are close fitting, roughly toothed, purplish to dark brown, spread outwards only slightly when open. The cones are not shed from the tree, but open at intervals to release the seeds gradually throughout the winter. The twigs are dark brown, covered with dense short hairs, outer bud scales are greyish and finely hairy.

In the bottom picture, it’s white spruce on the top and black spruce on the bottom with the spherical cone.

They key features for identification are the length of needles, shape and size of cones, and the twigs with or without hairs.

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