Juxtaposed to our dark evergreens, a tower of pale blue can deliver a powerful, icy accent to a Pacific Northwest landscape. And one of the few trees that does this is the Engleman Spruce, (Picea engelmanii). Like the bluer forms of its cousin, Colorado Spruce (Picea pungens), this is a timber-size tree, not suitable for every city garden, but a staple in our parks and at the far corners of spacious lots. It has a densely pyramidal form that can easily reach 60 feet and in time may tower to 130 feet. Its needles are softer than those of most other spruces. And if the lower branches are left on and the tree stays “dressed to the ground” (in horticultural jargon) it is likely to be no wider than 25 feet, a handsome screen and elegant backdrop to more delicate plantings. Give it a spot in the Northeast of any garden to minimize the shade it casts. Also remember that any big conifer will pull a lot of water out of the surrounding soil in the hot months, so get out your gardening books and start learning about dry-shade plantsmanship.
Native from British Columbia, all the way South to Northern California, this tree had, for whatever reason, the reputation of being less successful down near sea level and in the relatively mild Winters of our area. It was said to be happiest at high altitudes where seasonal freezes and snows were plentiful along with bright days. That hasn’t proven true. This spruce seems to do well in our climate.
For gardeners who favor buying potted conifers as Christmas trees, Engleman Spruce has long been a favorite. It will survive (not always happily) several weeks indoors, given ample water and a relatively cool room, plus the lights and decorations of the Holidays. But once outside, planted in the ground in January and watered-in well, it snaps back.
Spruces have the advantage of being adaptable to most soil types, so our typically rich acid soil suits them perfectly. The cones are pendent, meaning they hang down. When they drop, bring them in and watch them open— cylinders of tightly lined and relatively small scales, most often around 4-inches in length. They’re quite interesting filling baskets, with other cones, twigs and nuts, although their sap makes them a bit sticky to handle. A tip for removing, sap from fingers and hands is to use a bit of salad oil rubbed into the sticky surface, wiped off with a paper towel.
In general spruces require minimal pruning. If a branch shoots out too far, snip it back and enjoy it indoors. Pull the needles back with one hand and make a clean diagonal cut. When you release the needles, they’ll cover the severed tip and the branches will likely set two or more buds near the cut end. Most nurseries will have spruces in 15-gallon containers, for sale now. You can plant them immediately as a New Year’s perk-up for your Winter garden. Dig a generous hole. Loosen the roots once the tree is out of the container. Plant it with the top of the contained rootball even with the surrounding soil surface or, perhaps, an inch below in what amounts to a shallow dish, to encourage rain water to seep down to the newly planted tree. Early next Summer scatter a bit of balanced fertilizer around the trunk and drip line, but not too much. A half cup of 12-12-12 loosely broadcast and watered-in, assures that it does not run off and enter our water system. A top dressing of compost is better.
And there you have it. You’ve embraced the Mid Winter Blues and will see just what this tree with its cool, strangely pensive hue can do to add form, texture and color to your garden.