The same tree shows up under several blue spruce other names, and the list is short once you see it. People call it Colorado blue spruce, Colorado spruce, or silver spruce. The botanical name is Picea pungens. All four labels point to one tree. The wording just shifts from one nursery tag to the next, which is where the confusion starts.
That mix of names trips up shoppers who try to compare plants side by side. One tag reads silver spruce. The tag right next to it reads Colorado spruce. They look like two different trees on paper. But you are often staring at the exact same plant, priced two different ways, sitting a few feet apart in the same row of pots.
It helps to know that each name comes from a real trait of the tree. The botanical name has a clear meaning. The regional names tie back to where the tree grows. And the color words describe something you can see and feel. Once you connect each name to its source, the labels stop fighting each other and start to make sense.
The botanical name Picea pungens translates to sharp-pointed spruce. That is a nod to the stiff, prickly needles. Grab a branch with a bare hand and the tips poke you, which is the trait the Latin name calls out. Colorado, in turn, points to the tree's native range high in the Rocky Mountains, where it grows wild along streams and slopes.
Silver and blue both describe the same thing. The needles wear a waxy, powder-like coating that botanists call glaucous wax. That wax sits on the surface of each needle and scatters light. The green underneath then reads to your eye as a soft silvery blue. Rub a needle between two fingers and some of the coating wipes off, leaving a greener streak where your skin touched it.
The blue is not the same all year. It runs strongest on new growth in spring, when the fresh needles carry the most wax. As summer wears on, the coating thins a bit and the color softens. So a tree you buy in May may look more vivid than the same tree judged in late August. Keep that in mind when you compare two plants on different days.
There is good reason the Colorado names stuck so hard. This tree is the state tree of both Colorado and Utah. That status pushed the regional name far past garden circles and into common speech. You will hear Colorado blue spruce in seed catalogs and at the garden center. The name shows up even in states that sit nowhere near the mountains where the tree grows wild.
So which name should guide your purchase? Match the botanical name Picea pungens every single time. A common name can mean slightly different things to different sellers. The Latin name does not drift. It locks in the exact species you want. If a tag lists only a folksy name like silver spruce, ask the seller to confirm the plant is Picea pungens before you pay for it.
One more step saves you a real headache later. Check the cultivar name printed after the species. That single word controls the form and the final size you bring home. A Fat Albert grows wide and full to about 15 feet tall. A Baby Blue Eyes stays far more compact and tidy. Buy the species and the cultivar together and you get the right tree, no matter which common name the shop prefers to use.
Read the full article: Blue Spruce: Complete Care and Growing Guide
