GROWING GREVILLEAS VHT118

Grevilleas are a wide group of plants, all but seven species coming from Australia. They are widespread across Australia, occurring in both cool temperate, and hot tropical climates.

There are around 250 species. About half of these are native to the south west corner of Australia.

Known commonly as "Spider Flowers"; the Grevillea flower is more like a brush than a traditional flower. It has obscure petals, but is none the less very colourful. Flower colour varies greatly; and most hold their flowers for a long period.

Grevilleas include both small to very large plants (from prostrate ground covers, through small and medium shrubs up to large trees). Their hardiness is variable according to species. The foliage is also variable ranging from small, entire leaves to lobed or pinnate leaves. All are arranged alternately on the stems and some have hairy undersurfaces. Most have a medium to fast growth rate.

The way you should treat a particular species of Grevillea will differ from place to place, and according to what you are trying to get from the plant.

Lesson Structure

There are 8 lessons in this course:

1. Introduction.
   • Scope and Nature of the Grevillea genus
   • Review of the system of plant identification
   • Botanical Terminology used to describe Grevilleas
   • Flower Structure
   • Plant Name Pronunciation
   • Characteristics of the Proteaceae family
   • Characteristics of the Grevillea genus
   • Different ways of classifying Grevilleas into groups: by flower type (eg. toothbrush); McGilveray's system dividing into 11 groups
   • Resources, information contacts (ie: nurseries, seed, clubs etc.)
2. Culture
   • Environment, Nutrition, Soil Requirements
   • Planting, staking, mulching
   • Water management
   • Pest and disease found on Grevilleas
   • Feeding, pruning, protection from wind, salt air, etc.
3. Propagation
   • Methods of propagating Grevilleas
   • Cutting Propagation
   • Methods to Improve Cutting Success
   • Seed Propagation of Grevilleas
   • Transplanting
   • Hardening off and Growing on Young Plants
   • Grafting Grevilleas
   • Tissue Culture and Aerial Layering
4. The Most Commonly Grown Varieties.
   • Clearview Hybrids
   • Grevillea banksii and banksii hybrids
   • Grevillea alpina
   • G. rosmarinifolia
   • G. dimorpha
   • G. lavandulaceae
5. Other Important Groups.
   • G. alpina cultivars and hybrids
   • G. rosmarinifolia cultivars
   • G. Poorinda hybrids
6. Other Grevillea Varieties.
   • Ground Cover Grevilleas
   • Trees
   • Review of many other species
7. Making The Best Use of Grevilleas
   • Cut Flowers
   • Bird Attracting
   • Scented Grevilleas
   • Container Growing Grevilleas
   • Potting and Types of containers
   • Growing Grevilleas in Baskets
   • Rock Gardens
   • Designing a Garden with Grevilleas; design principles, garden styles, drawing a plan
8. Special Assignment: On one selected plant or group.
   • Problem Based Learning Project
   • Plan the establishment of a collection of different cultivars of Grevilleas suited to growing in a specified locality.

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

• Identify a range of different Grevilleas.
• Explain the culture of different types of Grevilleas.
• Propagate different Grevilleas
• Discuss different uses for Grevilleas
• Compare identifiable characteristics and cultural preferences of a range of Grevilleas.
• Discuss a range of Grevillea hybrids and cultivars
• Identify and compare a range of commonly cultivated Grevilleas.
• Discuss one Grevillea species, cultivar or type in depth.

• Grevilleas are shallow rooted plants – mulch is beneficial to protect the roots from exposure and to retain moisture in the soil.
• Due to their shallow rooting - it is beneficial to stake grevilleas that are growing in raised beds.
• Grevilleas may be root-pruned (unlike many other native) – you can remove up to 1/3rd the root ball of pot bound specimens however it is advisable to use a rooting hormone to promote root growth afterwards.
• Grevilleas cannot be moved once they are established – very young plants can be moved in autumn to early spring - but will need extra attention to watering for some time after. Rooting hormones may be of benefit.
• Use only low phosphorus fertilisers.
• Select species to suit the environment in which they are to grow.
• Never buy pot-bound or sickly looking plants.
• Grevilleas will grow in pots but are best planted out before they reach 3 years old.
• Plant Grevilleas to attract birds to your garden to aid in pollination – you may just produce a new variety!
• Never plant grevilleas in heavy shade (though some tolerate light shade).