The name ‘conifer’ comes from Latin and means ‘to bear cones.’ Although cones are a common feature of most conifers, junipers and yews are two exceptions that produce berry-like fruit.
The best method of identifying a conifer is to look at the leaves. Conifers are usually evergreen trees or shrubs with linear, needle-like or scale-like leaves, though some species such as larch and cypress drop their leaves in autumn.
Amongst the conifer population are some of the smallest, largest and oldest living woody plants known. There are more than 500 conifer species distributed worldwide, invaluable for their timber as well as their adaptability as garden plants for year-round interest.
Conifers in the landscape
The diversity of available conifers for the landscape is tremendous. Nurseries and plantspeople around the world are devoted to the discovery and introduction of new selections that vary in size, form, colour and texture. There has been special interest in the group classified as ‘dwarf conifers’. (a dwarf conifer is one that fails to attain the size and stature of the parent plant).
Conifers under threat
Most people think of conifers flourishing in the vast commercial plantations of pines and spruce that dominate the landscapes of many parts of the world or in the great expanses of natural forests in Canada and Siberia. How can conifers be under threat when they appear to be so common? Well, these forests contain only about 10% of the known conifer species. The majority are found in small, scattered populations in both Northern and Southern Hemispheres.
Globally, conifer species are threatened with extinction. Of the world’s 800 taxa, 355 are listed by the World Conservation Union (IUCN) as being of conservation concern. Threats to their native habitats include logging, uncontrolled forest fires, open-cast mining, and conversion of forests to pasture and arable land. For example, a combination of these threats is the reason why 28 of the 43 conifer species endemic to the Pacific island of New Caledonia are of conservation concern.
From massive forest giants to miniscule mounds of elegant foliage, the appropriate size will depend on the landscape situation. The typical landscape today is limited in space, making size an important issue when choosing plants.
The form most commonly associated with conifers is the familiar conical shape of Christmas trees. However, the range varies from the vertical form of tall columnar plants to the horizontal form of flat ground covers.
Globose - globe-like or rounded in general outline.
Pendulous - upright or mounding, with varying degrees of weeping branches.
Narrow upright - much taller than broad; includes plants referred to as fastigiate, columnar, narrowly pyramidal or narrowly conical.
Broad upright - includes all other upright plants that do not fit into categories 1-3.
Prostrate - ground-hugging, carpeting plants without an inclination to grow upward.
Spreading - wider than they are tall.
Irregular - erratic growth pattern.
Culturally altered - pruned or trained into formal or imaginative shapes, such as high grafts or standards.
Garden conifers come in a rainbow of year-round colours that can be used effectively with companion plants. Many are shades of green, yellow, orange, blue, lavender or purple, while others are bicolour and have variegated foliage with patterns of stripes, spots and patches.
Many go through seasonal colour changes and provide interest in the winter landscape. In the spring, lighter shades of new growth contrast against the darker older foliage. In some cases, new growth emerges not just as a lighter shade but as a bright yellow or red, rivalling any floral display. Some even display two colours of needles. On other conifers, the cones and seed-bearing fruits are brightly coloured and decorative during certain seasons of the year.
How to use garden conifers
The landscape uses are limited only by the imagination. The strong silhouettes of many compact, slow-growing conifers can accent a corner of a garden bed, frame a doorway or add winter interest to perennial and annual flower beds.
Use conifers in foundation plantings, borders or island beds with other shrubs. Plant a mixture of different conifers, blending the various textures, shapes and colours, for a unique low-maintenance landscape.
Use large specimens amid expansive lawns and miniature specimens to view up close in containers, troughs or rock gardens. Don't forget that conifers are also stalwart hedging and windbreak plants.
The natural growth pattern of a normal or dwarf evergreen is a large part of its charm. When the wrong plant is selected or the right plant is not maintained properly, this charm may be lost as the conifer grows too large for its assigned space. At this point, you must choose between pruning, moving or removing; often removing and replacing the plant is easiest. Some evergreens can be severely pruned while others cannot. In most cases, severe pruning will destroy the conifer's natural charm, although some plants may recover over time.
Yews and hemlocks are the easiest to control. Both have abundant buds on old and new wood; these develop into twigs when the wood above is cut. Since they can be sheared heavily without permanent harm, they can be used as hedges. The leaves tolerate some shade, so they grow well on the inside of the plant and allow for shearing or pruning. Pruning in the spring just before the new growth begins allows the pruning cuts to be covered with new growth very rapidly, preventing the ‘just sheared’ look.
Firs, cedars, spruce and Douglas firs are also easy to manage. These have visible buds alongside the current season's growth; some also have buds alongside the stems of the previous year's growth. Size can be controlled at any time by pruning back to a bud. For a formal shape, prune or shear when the current season's growth is soft. These plants' leaves tolerate some shade, so pruning and shearing can potentially produce a dense plant.
Take more care with pines. When pruning, be aware that pines lack buds along the stem. Buds are only present at the tip of the current season's growth, so spring is the best time to prune pines. Soft new growth, called a ‘candle’, can be cut or pinched before the needles are fully elongated, and buds will develop from needle fascicles below the cut. This type of spring pruning or ‘candling’ will produce a compact plant. During the rest of the year, prune carefully or you may damage the plant's shape.
Junipers, arborvitaes and falsecypress (Chamaecyparis) are the most difficult to maintain at a particular size. 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. If you shear one of these plants, do so carefully while it is actively growing in the spring. The naked brown interior indicates that the leaves are intolerant of shade. 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 may not be covered for many years.
Conifer Introduction reprinted here courtesy of The American Conifer Society. We thank them for their support