"The associations in this book have been tested by me over the past 15 years. Some have been accidental observations which I have followed up; others have been folklore I have tested. Several associations discovered through current research in Europe, the USA and New Zealand, I have observed in Australia as well. The last five years seem to have been mostly spent on counting insects and measuring new shoots. But I hope it is at least a basis for companion planting that works in Australia and New Zealand. Scientific names have been included only where one plant might otherwise be confused with another." -- Taken from the Introduction.