This is a timely book to review seeing I've just started my new Breaking the Rules series. I'm pleased to see my planned snippets aren't covered, so everyone can read something new from both reading this book and my future posts :)
Decoding Gardening Advice looks at the top 100 pieces of advice given [in the USA, though most also apply to the UK - Ed] to see whether they're good, questionable or downright bad. Unlike most advice we see in books or on the TV - which have an unwritten or unspoken assumption they're all good - the reasoning behind their categorisation is given.
So thinking about the advice I've seen or researched recently, on the good side we have...
- Stop fertilising during very hot weather to reduce plant stress
- Water deeply and infrequently to encourage a strong root system
- Do not plant trees too deeply
... and on the debatable side there's...
- Follow spacing recommendations on plant labels
- Always stake young trees (Yay! Agreement with Tony Kirkham's talk - I had a some vigorous disagreement in the comments on this one)
- Plant vegetables in rows
...and then there's just plain wrong...
- Always add extra nitrogen to the soil when wood mulch is used
- After pruning, dress tree wounds to inhibit decay and insect infestation
- Use gravel or rocks at the bottom of containers to improve drainage (how many times do we see that going on?)
I'm not telling you any more about these, so you'll have to read the book ;)
There's eight sections to peruse:
- Pest, disease and weed control
- Annuals, perennials and bulbs
- Trees and shrubs
- Vegetables and fruits
- Lawn care
Some of the advice will seem obvious because it's been dinned into us for years as being good horticultural practice, but I still welcome the explanation of why that's so. I'm sure there's plenty of people out there who won't know it's the right thing to do, just as I'm also certain there's quite a few surprises in there for seasoned gardeners too.
Potential readers should note that this is a text heavy book with little in the way of illustration. On the whole this doesn't detract from the book's readability or clarity - there's a good blend of Jeff Gillman's associate professorship in horticulture and Meleah Maynard's journalistic roots. I found just one exception: I can't tell from the description on the correct pruning of trees and shrubs, whether it agrees or disagrees with the advice Kew's Tony Kirkham gave in the talk I attended last year. In this case, a photo or diagram would have helped.
As time goes on readers will need to start questioning the material in this book, just as the authors have evaluated the advice they've chosen to feature. For example, the use of compost tea and mycorrhizal fungi are debunked or rated as questionable respectively. However, when I went round RHS Wisley last year, I was told they're using both of these extensively and getting good results (RHS's Colin Crosbie via personal communication).
Future research will show who's right on this one and maybe refute some of the authors' other conclusions. I hope this book is revised and updated accordingly, otherwise it in turn will become a source of 'bad' advice like those which the authors are seeking to address.
Overall, I liked this book a lot. The authors have thoroughly reviewed the evidence available for the advice they've featured, and show why some of the 'received wisdom' about gardening is out of date or plain wrong. If we all start thinking about the gardening advice we receive and the reasoning behind why it is given, it'll help us all to become not only well informed gardeners, but better ones too.
Update: Quite a few of you were surprised at the crocks in pots being bad advice. Here's what Harriet Rycroft has to say on the subject. Seeing she spends a lot of her time planting up gorgeous pots at Whichford pottery, she should know what's right and wrong :)
Disclosure: I received a review copy of this book from the publishers.