How to navigate the growing labyrinth of horticultural knowledge
THE internet is burgeoning with info of every possible kind, while seed companies and nurseries entice you into falling for something, anything. And let’s not forget all those writers and broadcasters. How can you successfully navigate this maze of information?
I believe gardening tips should pass three tests – is the advice from a reliable source, does it take into account recent research and is the information suitable for where you live?
Google makes life easy. At the click of a mouse you can browse the sum of human knowledge, but sift with care. You can generally trust sites such as the RHS, Garden Organic and the BBC, but be more cautious with lesser-known sources.
We’re often drawn to the experiences of others in blogs, but again, tread carefully. One tip I came across was especially enlightening: “From each according to his ability, to each according to his needs.” Garden centres and mail order firms are more helpful than that, but they don’t want you to leave without splashing the cash.
Writers and broadcasters do their best, even if we don’t always agree with each other, but our advice must be up to date. Research often modifies or even throws a couthy old method out the window.
Take planting up a container, for example. As I wrote here in 2013, research showed the traditional technique of layering the bottom of a pot with broken crocks was wrong. It impedes, not helps, drainage. By 2015, Monty Don and others started recommending alternatives.
And should you double dig? A hundred years ago, one writer said “the town garden should be deeply dug and well manured, if not annually, at least every two years”. And this treatment should even be meted out to herbaceous borders. Everything but trees and shrubs should be howked out and replanted after the big dig.
Although I’ve never run amok in the flower border, I was brought up with double digging etched in my soul. It’s laborious but satisfying. The latest research by soil scientists, however, demonstrates that this cultivation disrupts the soil ecology and should be avoided where possible.
In our defence, garden writers can only offer general advice. Even so, homegrown tips will be more relevant than UK-wide advice. I always advise opting for quickgrowing veg because plants have a lot of work to do during a short growing season. This makes successional sowing more challenging, so late-maturing sprouts and leeks rarely perform as well as early ones.
As a general rule, you need a hot, sunny summer to grow tomatoes outdoors, whatever you hear from south of Hadrian’s Wall, and our feeble sun shines just as weakly in the flower garden. Although honeysuckles are fairly hardy, varieties such as Lonicera etrusca Superba need more sun than we get here. And you should be choosy with camellias. C x williamsii won’t let you down, but you’ll be hard-pressed to squeeze a flower out of a C japonica.
The sun isn’t everything. Geography and altitude are critical so there are no hard and fast rules for the whole country. Japanese maple, Acer japonica, tolerates “mild” midwinter cold, but can’t handle severe or late winter frosts and biting east winds.
The experts can help, but you need to know your own area and tailor advice to your particular garden. Will a plant get enough sun or shade, and, if relevant, can it tolerate salt? If you need a reference book, try Garden Plants for Scotland, co-written by my predecessor in these pages, Raoul Curtis-Machin, and Ray Cox.
Camellia x williamsii Saint Ewe is among the camellias that will thrive in Scotland, though you might struggle to hear such geographically specific advice from garden writers south of the Border