AUSTRALIAN NATIVE TREES

Learn to Select and Cultivate Australian Native Trees for Different Situations

• In tropical, temperate and cold climates
• From wet rain forests to dry deserts
• For timber and fruit production
• As windbreaks, shade trees and even indoor plants

Rainforest Trees

There are three major types of rainforest in Australia, each supporting different types of trees.  Tropical rainforests are only found in northern Queensland, and most closely approximate the 'jungle' habitat found in many tropical overseas regions. Subtropical rainforests are distributed from northern NSW into Queensland, whilst cool temperate rainforests occur at higher altitudes in Tasmania, Victoria, and NSW. 

Rainforests only occur in scattered pockets, with rainfall, topography, and soils being the main influences in their occurrence.  They are characterised by their diversity and complexity; well developed tree canopies support a myriad of life forms.

Although opinions amongst experts varies considerably, Eucalypt trees are generally considered not to grow in true rainforests (there is considerable debate in this area, for example, some taxonomists classify species such as E.grandis, Flooded Gum, as occurring in rainforests).  Typically, rainforest trees have lush, glossy foliage, broad canopies, large trunks, and buttressed roots.  There are many exceptions to this type of growth though.
Notable rainforest trees include: 

• Toona australis   Red Cedar
• Stenocarpus sinuatus   Firewheel Tree
• Acmena smithii   Lilly pilly
• Brachychiton acerifolius   Flame Tree
• Buckinghamia celsissima
• Castanospermum australe   Black Bean
• Diploglottis australis   Native Tamarind
• Ficus macrophylla   Moreton Bay Fig
• Grevillea robusta   Silky Oak
• Macadamia tetraphylla
• Melia azedarach   White Cedar

The rainforest is seen as one of the ultimate environments to duplicate in the garden for a private retreat.  It can be a home for many wild animals or a place for food.  It is easily "constructed" provided a few requirements are met to satisfy plant growth.  Protection from direct sunlight and strong wind and an abundant supply of mulch or leaf matter are three of the most important necessities for the establishment of a rainforest.  Understandably, if you already have a shaded site it makes your rainforest garden one step closer to completion.

There are many misconceptions about rainforests and the suitability of the plants that grow for domestic purposes. Let us look at some of them:

• Rainforest trees grow too large for gardens in the rainforest many trees will grow to heights exceeding 20 metres because they have to fight and grow to the light.  In garden situations, there is more light available and consequently, many of the same trees will only grow to about half their rainforest height.
• Full shade is essential for rainforest development many rainforest trees will grow in full sun and others may require some shade while young. As a result of more sunlight, these trees become more rounded with fuller canopies.  Understorey plants, however, require more shade than trees.
• A large area is required to develop a rainforest many people have successfully developed miniature rainforests in a 10 m x 10 m area.  The larger the area available the better the ecosystem can be developed.  However, the larger the area the more plant numbers will be needed to fill in the area.
• Perfectly drained deep volcanic soil is needed, once again this is a major misconception.  Provided a bit of extra pre-plant preparation is performed, any soil can be made suitable for a rainforest garden.  The better your soil is to begin with, the easier and quicker will be your established rainforest.
• High rainfall is essential for a rainforest with adequate compost or leaf litter, water is retained better in the soil, therefore, less hosing will be required.  With a dense canopy, evaporation is reduced therefore the need for extra water is not present.
• Only North Queensland has rainforests there are about six main rainforest systems throughout Australia from the tip of Queensland to the mountains of Tasmania.
• They are difficult to grow, many rainforest plants are extremely easy to grow, so much so that many are used as indoor plants (eg. Castanospermum australe) and others have been available throughout nurseries for decades (eg. Archontophoenix alexandrae).

Lesson Structure

There are 8 lessons in this course:

1. Introduction
   • Review of the system of plant identification
   • Genus, Species
   • Monocotyledons and Dicotyledons
   • Characteristics of main Australian Plant Families
   • General characteristics of native trees
   • Information contacts (ie: nurseries, seed, clubs, etc.)
   • History of nomenclature
   • International Code
   • Ranks of Taxa
   • Principle of priority
   • Selection and spelling of plant names
   • Changing names
   • Hybrids
2. Culture
   • Planting Procedure
   • Planting on slopes
   • Fertilizer
   • Time of planting
   • Staking
   • Mulching
   • Pruning native trees
   • Steps in removing a branch from a tree
   • Soils (Physical, chemical, biological structure)
   • Soil profile
   • Improving soil profile
   • Colloids
   • Water and air
   • Soil temperature
   • Soil life
   • Soil Problems (Loss of soil fertility, Erosion, Salinity, Soil compaction, Soil acidification, Build up of dangerous chemicals)
   • Improving soils (soil additives etc)
   • Limestone Underlay Technique
   • Fertilisers
   • Fertilising established trees
   • Plant Nutrition
   • Water Problems
   • Drainage
3. Choosing the right propagating technique
   • Seed
   • Seed sources
   • Hybrid seed production
   • Storing seed
   • Difficult seeds
   • Dormancy facftors
   • Maintaining genetic identity
   • Propagating Media
   • Propagating Eucalypts
   • Propagating Acacias
   • Cuttings
   • Improving cutting success rates
   • Grafting
   • Top graft
   • Whip & Tongue graft
   • Irrigated graft
   • Grafting selected plants¦ Eucalypts, Grevilleas, Banksias, Hakeas
   • After care of seed and cuttings
   • Transplanting (seedlings, cuttings)
   • Potting up plants and Growing on
4. Most Commonly Grown Varieties
   • Review dozens of relevant genera
   • Allocasuarina
   • Casuarina
   • Melia
   • Pittosporum
   • Acacia
5. More About Important Groups
   • Eucalyptus
   • Banksia
   • Brachychiton
   • Grevillea
   • Diagnosing Tree Problems
   • Tree Surgery Techniques
6. Other Varieties
   • Rainforest Trees
   • Constructing a Rainforest
   • Acmena
   • Eugenia
   • Mallotus
   • Melicope (Euodia)
   • Neolitsia
   • Nothofagus
   • Schefflera
   • Stenocarpus
   • Syzygium
   • Araucaria
   • Agathis
   • Actinostrobus
   • Callitris
   • Podocarpus
   • Adansonia
   • Agonis
   • Albizzia
   • Alstonia
   • Alphotinia
   • Angophora
   • Barklya
   • Buckinghamia
   • Castenospermum
   • Elaeocarpus
   • Ficus
   • Macadamia
   • Melia
   • Nuytsia
   • Tristania/Lophostemon
7. Making The Best Use of Native Plants
   • Why plant trees in the Landscape
   • Problems with trees
   • Biological controls
   • Parasitism
   • Symbiosis
   • Planting Techniques (Pocket planting, slope serration, Wattling, Planting arid sites, Direct seeding, Spray seeding)
   • Edible Australian Tree Crops (Davidsonia, Quandong, Backhousia, Citrus, Acacia, Syzygium, Tasmannia, Kunzea)
   • Australian indigenous timber trees
   • Essential oils
   • Useful Australian Conifers (Actinostrobus, Athrotaxus, Agathis, Araucaria, Callitris, Podocarpus)
   • Australian Indigenous Palms
8. Special Assignment
   • You select and conduct an in depth study of one plant genus or group (eg. Timber trees, conifers, trees from a particular region).

Aims

• To identify Australian Native Trees
• To describe the culture of Australian Native Trees.
• To propagate Australian Native Trees
• Compare characteristics and cultural requirements of different commonly grown species of Australian Native Trees.
• To compare characteristics and cultural requirements of conifer and rainforest species of Australian Native Trees.
• To describe a range of uses for Australian native trees.
• To study one type of Australian Native Tree in depth.

Eucalypts

Eucalypts can be grown across a very wide range of climates, provided you choose the right cultivar for the situation in which it is grown. Some will grow in arid areas and tolerate extended droughts, others grow in swamp land; some tolerate very cold conditions and can survive months of snow every year; while others do well in high humidity and tropical conditions.

• In optimum conditions the growth rate fan be fast; but in poor circumstances a plant may survive but take a long time to reach full size.
• Most species live for a long time, commonly well over a hundred years, sometimes several hundred years.
• Most species respond well to a variety of soil and climatic conditions.
• Root systems generally deep and vigorous.
• Should not be transplanted as large plants.
• If pollarded (ie: the top cut out to reduce height etc.) once, then this must be redone at least every 2 to 3 years to avoid branches falling.
• Established trees respond to feeding and deep watering in dry seasons.

• Eucalyptus –flowers have no petals; flower buds have an operculum (ie. Cap)
• Angophora –flowers have tiny petals; flower buds have no operculum

In 1934 W. F. Blakely (from the Sydney Royal Botanic Gardens), classified Eucalyptus into 606 different species and varieties. In 1971, L.D. Pryor and L.A.S. Johnson revised Blakely’s classification and divided the genus into seven sub genera. This work was not formally published though.

BENEFITS OF THIS COURSE

Most students will study this course primarily to improve their plant knowledge. At the conclusion of your studies, you will certainly know more about trees that are indigenous to Australia. You will have a raised awareness of the nature and scope of Australian trees and their commercial potential in the world today. You will be able to identify more genera and consider more species when making decisions about what to grow where.

This course may be a one off study program for people with a passion for native trees, perhaps an amateur native plant enthusiast, or maybe someone working with native trees already.

The course can enlighten and vastly improve the way you select, plant, grow and use native trees in a wide range of situations, including:

• Parks and Gardens
• Land Conservation and Rehabilitation
• Farms
• Street Trees and Roadside Plantations
• Cut Flower Production
• Landscaping
• Forestry