Conifers

Learn to Identify and Grow Conifers

Conifers are widely used as ornamental plants and timber trees. Some conifers even provide us with medicines, edible nuts and other useful products. Learn to grow and use conifers, and take a step toward becoming a conifer expert with this unique course.

"Unlike many other plants; most conifers are grown for their year round, stunning and varied foliage affects rather than their seasonal flower displays. Grow conifers in places that you want to look stunning all year round, and not just part of the year"  John Mason, author of Growing Conifers, published by Kangaroo Press.

Lesson Structure

There are 9 lessons in this course:

1. Introduction
   • Review the system of plant identification, general characteristics of the conifer plant group, information contacts you can use (ie: nurseries, seed, clubs, etc).
2. Culture
   • Planting, staking, mulching, watering, pest & disease, feeding, pruning, protection from wind, salt air, propagation, etc.
3. Trees
   • Conifers that reach tree proportions, their characteristics and requirements, how to grow conifers by seed propagation and grafting techniques.
4. Common Medium Size Shrubs
   • Many conifers fall into this height category. Some of the popular conifers are Chamaecyparis, Juniperus and Thuja. How to prune conifers.
5. Small Shrubs
   • How to choose small and prostrate conifers and their care. How to care for seedlings up to planting out stage.
6. Australian Native Conifers
   • Araucaria, Callitris, Podocarpus are three good conifers for use. The importance of environmental zones in Australia and how it can effect plant growth.
7. Rarer Conifers
   • Hemlocks, Podocarpus, Larches and leaf characteristics of Cephalotaxus.
8. Using Conifers
   • As timber, oils, edible seed, christmas trees, etc.
9. Landscaping with Conifers
   • This was originally developed in conjunction with the Rural Industries Industry Training Board in Queensland. Notes are continually upgraded to maintain relevance to current and future needs.

Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.

Aims

• Distinguish between different types of conifers in cultivation, including twenty-five different genera and fifty different varieties.
• Specify the general cultural requirements of different conifer genera.
• Determine specific cultural requirements for some commonly cultivated conifer species.
• Specify specific cultural requirements for some lesser grown conifers, including Australian native and uncommon species.
• Determine different commercial applications for conifers in horticulture.
• Prepare a planting design using conifers.

What You Will Do

• Describe the binomial system used for naming plants, using examples of two conifers.
• Distinguish, using labelled illustrations, between different conifer families, including: Pinaceae, Taxodiaceae, Cupressaceae, Podocarpaceae, Araucariaceae and Taxaceae.
• Use a botanical key to identify two different conifer genera.
• Compile a resource information guide for conifers, including scope of operation and contact information (ie: address, phone, fax), for 30 different contacts, including:
  • nurseries
  • clubs/societies
  • product suppliers
  • other organisations
• Prepare reviews of fifty conifers, not collected elsewhere, each including:
  • a photo, drawing or pressed specimen
  • plant names (scientific and common)
  • cultural details
  • uses/applications.
• Propagate five different conifers, using at least three different techniques.
• Determine the preferred soil requirements, for typical conifers, in your locality.
• Prepare a potting media suitable for container growing an advanced conifer, in a tub.
• Explain the planting requirements which are common to most conifers in your locality.
• Explain irrigation techniques appropriate for conifer culture, in your locality.
• Explain the nutrition requirements of two different conifer species, from different families.
• Explain five health problems common to conifers, including identifying features, significance to the plant, and control.
• Describe how to prune two different conifer species, in your locality.
• Determine two routine cultural procedures, to be undertaken in each month of the year, with conifers in your locality.
• Describe ten conifer species, growing in a specified locality, including:
  • plant description
  • preferred habitat
  • propagation
  • growing requirements
  • uses
• Compare the cultural requirements of ten commonly grown conifer species.
• Explain why it is often difficult to grow other plants beneath the canopy of conifers.
• Determine procedures for successfully establishing two specified conifer species on a specific site which you survey.
• Determine any native conifers endemic to your locality or nearby localities.
• Describe the different features of six specific native conifer species, including:
  • plant description
  • natural habitat
  • propagation
  • growing requirements
  • uses
• Describe different features of five specified uncommonly grown conifer cultivars, including:
  • height
  • foliage colour
  • foliage shape
  • preferred site
  • hardiness
• Determine two different "non standard" propagation techniques, that may be successful in propagating "rare" and uncommonly cultivated conifer species.
• Formulate a schedule of cultural tasks to be undertaken over a twelve month period, to establish new plantings of a conifer species not commonly grown in your locality.
• Determine ten conifer varieties, including at least five different species, suitable for pot culture.
• Determine five conifer varieties suitable for hedging.
• Compare cultural techniques required for growing two specified conifers in containers with growing them in the ground.
• Describe the culture of conifers in different situations, including:
  • as topiary
  • as bonsai
  • as a hedge
  • as a rockery planting
  • as screening
• Determine conifer species which have commercial value as a plantation crop, including:
  • timber
  • essential oils
  • foliage/filler for florists
• Evaluate the use of conifers, in a garden with both conifers and flowering plants, using a supplied checklist of design criteria.
• Evaluate the use of conifers, in a garden which is either all, or predominantly conifers, using a supplied checklist of design criteria.
• Design a conifer garden bed of thirty square meters, which incorporates at least ten different conifer varieties, and satisfies both aesthetic and cultural requirements of a specified site, that you survey.

Pines are evergreens, vary greatly in size, cones are hard, woody and have thick scales. Branches grow out of main trunk in whorls (making pines easy to climb). Foliage: They are readily distinguishable from all other conifers because most of their leaves are in groups, usually 2   5 on short spurs the number of needles emerging from a spur (ie. per bundle) can be a good indication of which species you are looking at.

Most are generally very hardy once established. For most pines it is important to retain a single strong leader (top growth point); if the tip is damaged, new growths will emerge, the strongest of which should be retained and the others removed. Once the plant reaches the ultimate height, the dominance of the tip decreases and the top flattens...there is no point in encouraging a single leader after this happens.

Pruning should be minimal if you want a well formed tree, however any pruning that is done should preferably be done in spring.

Though generally resistant to serious problems, a wide range of pests and diseases have been recorded on pines, including: damping off and root rot (particularly on seedlings, die back (more serious on younger plants), rusts, blights, wood rots; aphids, caterpillars, sawfly, web worms, scale, leaf miners borers, and weevils.

Pines can also suffer from soil problems. A deficiency or excess of water can cause needles to drop. root damage or nutrient deficiencies may cause stunted growth. Air pollution and salt have also been known to severely effect (sometimes kill) pines.

How to Propagate Pines
Seed is common, cuttings or grafting occasionally. Cones are slow to develop, maturing at the end of summer or into autumn of the second season  following their initiation. In most species, cones open to drop seed soon after ripening, so collect cones at this stage and air dry to release seed. Some species have cones which only open and disperse seed after firing (eg. P. attenuata, P. contorta, P. muricata, P. pungens and P. radiata). Such cones can be opened by applying heat or dipping into boiling water.

Seed will maintain viability if stored dry and at low temperatures. Germination can be variable between species. Many will germinate without stratification, but for some, stratification is essential. Stratify by soaking in water for 24hrs, then placing in a bag with moist peat or perlite in the bottom of a refrigerator (around 1-2oC) for a period (some species require 3 months stratification, others only 2-4 weeks).

Most species can be grafted onto seedlings in winter, most commonly using a side graft. The rootstock selected will be dependant upon the cultivar being grafted (not all pines graft well onto all species).
Low growing cultivars (eg. Pinus mugo var. mugo) are sometimes grown by cuttings -use fungicide and a higher rate of hormone.

WHAT CAN THIS COURSE DO FOR YOU?