Gardening: Options for replacing downed blue spruces
But before we talk about replacing the trees, let’s look at why a number of these prickly monsters were uprooted by the record winds. First the obvious: Blue spruces are very dense, tall and wide so they catch the wind easily. For this reason, they are often used in shelter belts in open country to protect structures. Unfortunately, as we found out, they have a limit and paid the price in the November storm.
The other factor is that we spoiled these trees. We kept them so well watered in our landscapes that their roots didn’t need to go very deep for the moisture they needed. As a result the roots never developed a broad, deep root system that would have held them in place in the wind. Morale to the story; water trees for several hours with a soaker hose every two to three weeks during the summer to get water deep into the soil and give the trees a reason to send their roots deep.
I am assuming that most people want to replace their spruces with conifers with a slightly bluish color. Here are a few of my alternatives.
Concolor or white fir (Abies concolor) is very slow-growing for the first 30 years of its long life. It ultimately can reach over 100 feet. It needs regular irrigation in the drier summer months. The tree has strong horizontal branching with a slightly open structure with 2- to 3-inch long silvery green needles and upright green to purple cones. It is somewhat shade tolerant. They are commonly sold as a Christmas tree.
Swiss stone pine (Pinus cembra) is a stately, upright growing tree in its youth with 2- to 3-inch needles borne in five-needle bundles around each branch. It will slowly grow to 30 to 40 feet and its branch structure will open up with age. It needs a sunny location with deep watering during the summer. Its purplish blue 3-inch cones will eventually yield edible pine nuts in 12 to 15 years.
Norway spruce (Picea abies) is a large, pyramidal conifer that can eventually grow up to 60 feet. It’s dark green needles spiral around its branches creating an interesting texture in the landscape. If your old blue spruce served as a wind break, a Norway spruce might be a good replacement. It needs full sun and irrigation in the summer. There are a number of cultivars on the market including weeping ones that stay under 15 feet.
Limber pine (Pinus felxilis) is related broadly to white pine. Vanderwolf’s Pyramid is a widely available cultivar that can grow 30 feet tall and 15 feet wide with a pyramidal habit that opens up over time. The silvery blue green needles are closely spaced and twisted, giving the tree a dense look. It needs full sun and deep periodic irrigation in the heat of the summer.
Pat Munts is co-author of Northwest Gardener’s Handbook. She can be reached at pat@inland nwgardening.com.