Creatures in the garden

Sunday, 23 March 2014

Shrubby Begonia arborescens

How times have changed! When I first began gardening more than 30 years ago, we had an arsenal of poisonous sprays with which we regularly attacked 'pests' on our plants. I cringe to think of what we did in those days, when we had an 'us against them' mentality that seemed to be the accepted ethos of the time. A pest and disease book I owned at the time listed all the baddies in the garden and what to spray them with. Useful insects were not mentioned. In this week's blog I am reviewing a new book published by the CSIRO, written by F. David Hockings - Pests, Diseases and Beneficials - which shows a different sort of thinking about the diverse creatures that inhabit our gardens, and how many of these play a positive role in controlling the more destructive sorts. Even some forms of fungi can apparently be directly or indirectly helpful to plants.

The book has five chapters of text, followed by more than 200 pages of photographic illustrations with captions. In the early part of the book, the author outlines the complex classification of the many small creatures that I would have previously simply referred to as 'insects', an erroneous belief as I now understand. I never realised where or how creatures such as snails, earthworms, spiders, mites, nematodes, slaters and centipedes fitted into the scheme of things in the animal world, or that the term 'bug' refers to a specific sort of insect, and I found this information fascinating. The life cycle, activities and feeding habits of each type are outlined (including particular plants attacked, where relevant), as are its predators. It might have been useful to have a diagram in this chapter showing the various branches of the Animal Kingdom, as at times I found myself lost in the phylums, subphylums, classes, orders, suborders and superfamilies that classify these creatures. Bacteria, viruses and fungi that have an impact on plants are also covered.

Grasshoppers can be destructive; pictured in my garden

The photographs of each type of creature are organised into chapters according to what part of the plant they are found on. I found the close-up illustrations to be of good quality, and the environmental impact of the creature is also usually shown in the photo, which is very helpful. The captions, on the whole, are informative. I found it inspiring to see how many beneficial creatures there are in a garden, and what they look like. The sheer diversity of these life forms - of both pests and beneficials - is quite mind-boggling, and becoming aware of the complex interrelationships between them left me feeling that human intervention with poisons is a foolish idea in most cases. Along the way, the author does give quite a few tips for dealing with problems in less toxic ways - such as physical removal, using organic mulches, pruning, crop rotation or simply turning a blind eye to minor damage rather than reaching instinctively for the spray gun in every case. The systemic pesticides of the olden days killed all creatures that came in contact with the sprayed plant - the good and the bad.

The author does acknowledge where sprays may be necessary to control difficult problems and provides a summary at the end of the book indicating what chemicals are appropriate to different issues (which I personally would not use) - but this is not a major focus of the book. The use of less toxic options, such as horticultural oils and soaps, and biological pesticides, is encouraged. The author includes (and explains) some biological 'horticultural problems' that are sometimes thought by gardeners to be due to pests or diseases, but which are in fact due to other causes, and illustrations of various deficiencies or toxicities of elements such as iron and phosphorous in plants are also useful.

Bees are essential in our gardens, and can be killed by some pesticides. Photograph: garden of Sandra Wilson in Sydney

I did feel that perhaps that the way the book was structured was a little unwieldy, with many cross-references between sections being needed because the creatures weren't all grouped together by type in the illustrated part of the book, and because the main explanatory information about each type was in the first five chapters. I also felt that the 'free-ranging small animal' section at the end of the book seemed a bit of an after-thought and thus incomplete - and it made no mention of the chief free-ranging foe in my garden at present: the brush turkey!

Overall, I enjoyed reading this book and found the author's enthusiasm for his subject to be contagious: I want to become far more aware of all the creatures in my garden, and encourage the beneficial ones as much as I can, and subdue the more destructive pests without unduly disturbing the intricate web of nature that exists in all of our gardens.