The recent flurry of media stories about putting crocks at the bottom of containers to improve drainage, calling it a “crackpot idea”, is perhaps the beginning of much more rethinking about ‘the rules’ of gardening.

In my book, Gardening Myths and Misconceptions, there are many ideas for saving time and working better, and I do cover the question of pot drainage, explaining how water makes a capillary barrier between fine compost above and crocks below. It drains if you over-water, but it also drains without the crocks, and in the latter case you have more compost for plants to feed from, and to hold moisture.

Some of the myths I cover may be difficult to believe, such as that you can put blighted tomato and potato leaves on a compost heap. The reason is simple: blight spores can survive only on living plant tissue. There is none of that by winter, let alone by spring or summer when you might use the compost. I have practiced this for thirty years with no ill effect.

But all the time the opposite is repeated, and blighted foliage must be burnt. It’s a terrible waste and rarely, if ever, questioned. Yet you should question things, especially statements which are not backed with a sound reason.

I am the kind of gardener who does ask questions and I am trying new methods all the time, particularly when they offer a saving of time and resources. I stopped washing my pots and trays thirty years ago, after doing it once and seeing for myself that it made no difference; The RHS finally agreed quite recently.

Similarly, I have always watered plants in bright sunlight, should they look in need of moisture, and have never noticed any ill effects. Think of April showers! So I was pleased to read that a study at the University of Budapest in 2009 had confirmed that water evaporates before scorching can occur.

Watering in the morning is another one: where did that idea come from to water in the evening and save moisture? Presumably a dry climate and not Britain, where slugs come out and play when it is moist after evening watering, and mildew can build up on leaves.

All the Myths I discuss have been well checked by my own experience, if not by the work of others. Nothing is pulled out of thin air, nor is it based on just one trial or experience. Some are more misunderstandings than myths but its good to air them for clarity.

For example, the rotation of vegetables, which is often taught as though it is obligatory and that you are doomed to failure if less than four years lapse before growing vegetables of the same family in one place. Rotation is a sound principle, an excellent idea, but there is no reason it has to be four years, and how you garden in other ways can effect the supposed build-up of disease or decline of fertility. A recent TV programme featured a Frenchman growing onions in the same place for decades, with wonderful results. I am not advocating that you do the same, just saying that rotation is a principle to play with rather than a rule to be governed by.

Gardening is full of great principles and sound ideas about the joy of working with and understanding nature. Let’s find more of that and worry less about being governed by supposed authority, as Val Bourne put it in the Telegraph of 23 April:

“superstition, misinformation and strange practices are still with us today – and they’ll probably persist. For many who write about gardening, I fear, rarely handle a plant.”

Gardening Myths and Misconceptions, Dowding, £9.95 – www.greenbooks.co.uk/myths

Charles Dowding is an experienced organic gardener and author of several books, including Organic Gardening: the natural, no-dig way, How to Grow Winter Vegetables, Salad Leaves for All Seasons.
@charlesdowding