The term “conifer,” describes most of the evergreen trees that we are familiar with in the Minnesota landscape. Is it a pine, a fir or a spruce tree? If you answer, ‘Christmas Tree’, you are correct, but I thought I would look a little further into the question. Following are tips that can be used to identify your tree. Several species can be distinguished by a variety of their characteristics, including needles, cones and bark.

Needles

Like deciduous trees, conifers can be identified by their leaves. The leaves of conifers are their needles. On pine trees, the needles that come out of the same spot on a twig are arranged and attached to the branches in clusters of two (red pine group), three (yellow pine group), or five (white pine group) needles per cluster. Pine needles are so soft and flexible that they produce the tell-tale whisper as wind moves through them.

Spruce and fir trees have their needles attached individually to the branches. Pull off a needle, and roll it between your fingers. If it feels flat and does not roll easily, it is a fir. If the needle has four sides and rolls easily between your fingers, it is a spruce. Spruce needles are sharply pointed, stiff and tend to be shorter than those of pines – roughly 1 inch long. Each sharp needle erupts from the branch on a tiny, woody peg. When needles are shed, these projections remain. As a result, the branches of spruce trees feel rough. Fir needles are softer. Fir branches lack the woody projections, and thus have smooth bark. The color and length of needles are not reliable means of identification; these can vary from tree to tree, depending on cultural conditions and the planting site.

Cones

All conifers produce cones; which are incorrectly called pinecones since not all conifers that produce cones are pines. Cones are made up of papery-thin scales attached to a center stalk. In between the overlapping scales the seeds can be found. The scales on the cones help us identify the various species.

Pinecone scales are woody in nature, noticeable thick, rigid and tough. In contrast, spruce cones have thinner scales than pinecones, which give them a more flexible feel. Spruce cones hang down on the branch, pointing toward the ground. Fir cones perch on the topmost branches. They often glisten with drops of fragrant, sticky resin. Cones of firs do not fall intact like other conifer cones. In late fall, their scales tumble off one by one when the seeds have ripened. As a result, cones can only be used to recognize firs in summer and early fall.

The length of cone is not a reliable way of differentiating most types of conifers because the length can vary from tree to tree. For example the sugar pine cones range in size from 8 inches long to more than 26 inches long.

Bark

Bark alone is not a fully reliable indicator of the type of conifer you have. The best way to identify conifers is to examine the needles and cones along with the bark. In general the bark of pine trees is smooth on young trees but develops a flaky, reddish-brown color with age. Scots pines have a particularly orange/red peeling bark. White pines can have smooth bark, even when mature. The bark on spruce trees is generally rough to touch and becomes furrowed and scaly with age. Fir trees have smooth bark that is often grayish when young, but develops a furrowed appearance as it ages.

Needle Drop

All conifers shed needles — sometimes this shedding is slow, but most commonly it occurs all at once in the fall. Because the oldest needles are shed, the inner areas of the tree closer to the trunk become less dense than the outer areas.

For example, pine trees tend to keep one to three years of needles active, and in the fall the older needles turn a yellow-brown before they are shed. The pine species showing the most brilliant color change in most years include white, Austrian and Scotch. The color change is also noticeable on spruce and fir. This color change occurs each year, but some years it is more noticeable.

As long as the color change is in the inner portion of the tree and in the fall, the homeowner should have no worries. If the needle discoloration is on this new growth or at a different time of the year than fall or winter, then you should be concerned and check further to see what is happening. So instead of worrying, enjoy the fall color of your conifer trees.

The next time someone asks you what kind of tree you have in your yard, you no longer have to answer ‘Christmas Tree’, you will know if your tree is a pine, a fir or a spruce.