Collecting Conifer Greens for the Holidays
by Michelle Le Strange, Master Gardener Advisor

During the holiday season, there is always a need for evergreen branches and foliage for decoration. I often can be seen trouncing around county grounds with pruning shears in hand, seeking branches of cedar for the mantle, pine for the wreath or bay for garlands.

This is a good time of year to lightly prune many evergreens. There is less likelihood of borers infesting freshly cut branches because the insects are not active now, and wounds will close before summer to protect the trees from damage.

Anatomy of an evergreen tree. Evergreen trees have leaves that persist year round and include most conifers and some broad-leaved trees. In general, they need less pruning than deciduous trees. Conifers are distinguished from broadleaf evergreens by their needle or scale like leaves and their seed-bearing cones.

Conifer families. Taxonomically there are four families of conifers: pines, cypress, bald cypress, and yew. Pines, firs, hemlocks and spruce are members of the pine family. In the cypress family are cypress, cedars, arborvitaes, and junipers. Redwoods belong to the bald cypress family and yews are in the yew family. Among the conifers are some of the smallest, largest, and oldest living woody plants known.

Conifer forms. The form most commonly associated with conifers is the conical shape of Christmas trees. Next time you're outside take a panoramic view of just about any neighborhood in the valley or foothills. Notice the globe shape of the arborvitae, the pendulous deodar cedar with its weeping branches, the columnar Italian cypress, the spreading shape of the juniper shrubs, and the prostrate form of the groundcover junipers.

Branch arrangement. Evergreen conifers are also grouped according to how their branches are arranged on the trunk. Branches can be whorled or random. Pine, spruce, fir, and redwood have whorled branches that form a circular pattern around the growing tip. Whorl-branched conifers usually have only one flush of growth each year in which these pre-formed shoots expand into stems that form the next whorl. Conifers with random branching habits include arborvitae, cedar, false cypress, juniper, and yew.

Pruning conifers can be tricky. If you prune the wrong way, you could get very little new growth. Over pruning can expose large limbs to sunburn, and then borers can infest the trees. The most important thing is to prune conifers only when necessary.

Because many conifers have strong central leaders (also called an excurrent growth habit), young trees rarely require training-type pruning. The leader is the vertical stem at the top of the trunk. Never cut the leader. If a young tree has two leaders, prune one out to prevent multiple leader development.

What to prune. Allow evergreen trees to grow in their natural form. The natural growth pattern is a large part of the conifer's appeal. Corrective pruning consists mainly of dead, diseased, or damaged branch removal. Remove dead wood promptly, by cutting dead branches back to healthy branches.

Pines - Be aware that pines lack buds along the stem. If you cut pine branches where there are no needles, then new buds or branches will not form and the old branches usually die. Buds are only present at the tip of the current season's growth. Selectively prune back to a bud in the foliage area of the branch, or back to a strong growing side branch. Another alternative is to remove the branch completely at the trunk.

Arborvitaes, junipers, and false cypress (Chamaecyparis) - This group's buds are present only where there are green leaves. A branch cut back to a non leafy region will not produce new foliage. Each plant in this group forms a thin shell of green growth surrounding a zone of leafless twigs and limbs. Take care not to open this shell during pruning, since the unsightly scar will remain for years. If you shear one of these plants do so carefully, while it is actively growing in the spring.

Cedars, firs, redwoods, and spruce - These trees have visible buds along the current season's growth; some also have buds along the stems of the previous year's growth. Control size at any time by pruning back to a bud.

Yews and hemlocks - These trees have abundant buds on old and new wood, hence they can be sheared heavily without permanent harm and are often used as hedges. Pruning in spring just before new growth begins allows the pruning cuts to be covered with new growth very rapidly.

Remember to carry your pruning shears on your next winter walk and gather conifer greens for your holiday décor. Who knows I might see you out there!

December 18, 2003