Conifers: Timeless Evergreens
Could conifers be making a strong comeback?
Conifers are an important group of largely evergreen plants that grow in many parts of the world, but are most significant in cold climates. They are vital to the global timber industry with a variety of different pines, spruces, firs and cypresses being grown and harvested on vast scales in both the northern and southern hemispheres. In the garden they can be found as anything from large trees to the tiniest of dwarf shrubs and spreading groundcovers, and most sizes and shapes in between. In nature some of the oldest living plants (pines) are conifers, while the largest living trees (giant redwoods) are also part of this extensive group of plants. Without conifers it’s safe to say that life on earth would be very different.
Multitudes of shapes, colours and sizes
Ornamental garden conifers come in an array of shapes and sizes as well as foliage textures. Add to this a range of contrasting colours from various shades of green to gold and yellow, silver, grey and blue, and even russet reds and browns, and you have enough variety for endless different planting combinations. But to make the most of gardening with conifers, you need to make sure that each plant type is used in the right context, which means you need to know which plant with which tongue-twisting name comes in which shapes, colours and sizes. Do this and you’ll be able to create a lovely landscape using predominantly conifers.
Numerous garden uses
There is a conifer for virtually plant application in gardens and landscapes, from huge shade trees to low-spreading groundcovers, hedges and boundary screens, to potted specimens around the swimming pool. Leyland’s cypresses are still planted extensively as large windbreaks and boundary hedges. They can be left to grow unchecked or be clipped into well-manicured hedges. Golden-foliaged conifers make spectacular sculptured specimens in borders or containers, their bright colour and year-round good looks making them much sought after. Dwarf conifers make excellent rock garden subjects. Given their cold tolerance and the fact that many look their best in winter, conifers and cold winter conditions are undoubtedly the perfect match.
Cultivation hints and tips
Conifers grow best in an open and exposed position with ample space for them to grow to maturity unimpeded. Competition from neighbouring plants is one of the main reasons for conifers losing condition in the garden. Full sun or dappled shade is fine. They prefer well-drained loamy soils but some types adapt better to damp or dry soil conditions than others. Applications of general garden fertiliser at recommended rates in spring and summer keeps them in top condition – don’t sprinkle any granular fertiliser onto the foliage as it burns conifers very easily. A thick layer of mulch spread over the soil surface under and between plants suppresses weed growth and reduces water requirements (and also looks neat and tidy). Check plants for any pests or diseases on a regular basis and treat accordingly. Most conifers are easy to grow and require minimal care and maintenance.
During the latter part of the last century conifers were a fashionable component of many gardens, especially in the colder regions, but their popularity has waned. Thankfully it now appears that conifers are making a deserved comeback to the garden scene, where their diversity of range and numerous practical applications in the landscape are unsurpassed. There are few substitutes for conifers and their important role in the gardening scene. Common sense will prevail and conifers will once again offer the comfort of dense boundary hedges, thick wide-spreading groundcovers and stately specimens in the landscape. Long live the conifer!
Questions and answers
Q: Do all conifers get attacked by European cypress aphids – an insect pest that has devastated some conifers in recent times? A: Not all conifer types are susceptible to aphid damage. Cypresses (Cupressus or Chamaecyparis) and some of the junipers (Juniperus scopulorum) seem to be the main targets. Aphids, which are tiny and difficult to detect, are a problem during autumn (April to June) and conifers need to be treated during this period. Preventative applications of suitable systemic insecticides need to be applied to vulnerable conifers. Thuja and Platycladus are not affected and don’t require any treatment.
Q: Can large, overgrown conifers be pruned back to keep them smaller in stature? A: As a general rule conifers can’t be cut back too hard. Most of them do not produce new growth from old hard wood that has no foliage left. This means that if the size and shape of conifers need to be controlled it should be done so with regular light pruning or shearing during late winter. This needs to be accomplished before new spring growth emerges. Remove the top 20 – 50mm of growth with hand or mechanical pruning shears.
Q: How do you propagate conifers for the garden? A: In nature, most conifers self-propagate by means of seeds. In horticulture many ornamental conifers are reproduced by means of tip cuttings taken in mid-winter. Some hybrids or cultivars don’t root easily from cutting and therefore have to be grafted in order to propagate true-to-type progeny. Seed-grown plants don’t always grow to be the same as their parent.
Q: Do all conifers produce cones? A: Conifers produce primitive flowers called strobili. These are short and catkin-like, with male and female parts on separate strobili either on the same plant, or in some instances on separate plants. Pollination is done by wind. Fruits then develop in the form of a woody cone on some conifers like pines, cedars and larches, while others form berry-like fruits, as in junipers and thujas.