Biodynamic gardening: sound sense or plain silly?

Dismissed by many as just so much silly hocus-pocus but fervently endorsed by others, the biodynamic practice of gardening in accordance with the rhythms of the moon is one of those thorny topics that firmly divides the world of horticulture.

Its best known advocate was the Austrian philosopher Rudolf Steiner, who argued that in order to promote their optimum health and vigour, the sowing, planting, pruning and harvesting of particular species of plants should be carried out on specific days of the month and in tune with the phases/rhythms of the lunar calendar.

The world of science disagreed, although that didn’t deter many gardeners from espousing Steiner’s theories. By the 1950s, a German biodynamic farmer by the name of Maria Thun was experimenting with growing different crops – broadly divided into “leafy”. “flowering”, “root” and “fruit”– according to the lunar constellations.

By the early 1960s, Thun’s conclusions had led her to start publishing an annual calendar in which she gave gardeners and farmers specific cultural advice based on the movements of the moon.

Agricultural astrology

Since then, moon gardening, or agricultural astrology as it's also known, has occupied a strange niche within the world of gardening. Various rigorous scientific tests carried out by the consumer magazine Which failed to conclusively prove any real benefits, leading one gardening expert writing in the Telegraph a few years ago to condemn the practice as harmless but "indicative of a slight softness of the brain". But others, including Britain's Prince Charles and the well-known organic gardener, author and no-dig expert Charles Dowding, are less sceptical.

Dowding has carried out his own tests, albeit on a very small scale, coming to the cautious conclusion that there are possibly modest gains to be made in terms of the size of harvest when food crops are sown in accordance with certain lunar rhythms. Carrots, for instance, gave him a greater yield when sown when the moon was “waxing” rather than “waning”.

But Dowding also sounds a strong note of common sense, making the point that gardening according to the moon is not only complicated but also isn’t all that practical.

“I think that most of us are mainly governed by fitting our gardening into life’s other demands, people and the weather, so there is a danger with prescriptive almanacs that they can make you feel bad for doing a job on the ‘wrong day’”.

Yet still the popularity of “moon gardening” endures. Maria Thun died in 2012, but her son Matthias continues to produce her lunar planting calendar, as do a host of others including the well-known biodynamic gardener Nick Kollerstrom. Will it give you better beetroot, or healthier roses? That’s the million-dollar question . . .