Lunar Gardening

Effects of the moon on plants

A Scientific explanation
Another scientific explanation
Biodynamic Lunar Planting
Yet another scientific explanation


[this icon gives gardening advice according to biodynamic principles. See the fruit and vegetable symbol for more info]

A great many gardeners believe that planting vegetables during specific phases of the moon, and/or when the moon is in a particular zodiac sign, is beneficial. Some almanacs are published especially for this purpose. Gardeners disagree on the exact details, but it is widely believed that planting when the moon is waxing ensures rapid germination and growth . Another idea is that vegetables which grow underground should be planted in the dark of the moon, and those which grow above ground should be planted at full moon
[2]. This sounds like sympathetic magic, but that doesn't mean that it won't work.
John Reid in "The Scots Gard'ner" (1683) [9] advises that
"Peas that you would have early, sow in the full moon of november, if in a warm place"
also that "great, white and red cabbages" should be sown in the full moon in july, and that roses should be pruned before the full moon in October.

In Wiltshire, there is an expression:
"Light Christmas, light harvest"[8] meaning that if there is a full moon at Christmas, the harvest will be poor.

The Maoris believed that the moon whom they call Rongo*, protects crops. They always planted sweet potatos on the 11th, 27th and 28th days of the lunar month. Their main agricultural tools are long spades with crescents carved into the handles[13]

The Miskito Indians of Eastern Nicaragua, believe that crops will spoil or the harvest will be light if they are harvested at new moon. They also believe that above ground plants should be planted between the first quarter and the full moon, and below ground plants should be planted between the full moon and the last quarter. The Miskito hold similar beliefs about the moon and animals[12]. It is worth remembering these words from Aristotle:

"It is even said that many ebbings and risings of the sea always come round with the moon and upon certain fixed days" [3]
Aristotle (who spent his whole life around the mediterranean) found this idea hard to swallow,(and considering some of the other things he believed, this is really saying something!). As a result, Julius Caesar was unaware of the tides** until he invaded Britain.


A scientific explanation

The following is taken from "Agricultural Ecology" by Girolami Azzi,

"According to experienced farmers, lettuce sown when the moon is waning is well developed vegetatively, producing a voluminous and juicy head: If sown with a rising moon, the plants rapidly go to seed without forming a good head.
Radishes sown with a rising moon blossom in 50-60 days when temperatures are reasonably high: sown with a waning moon, the interval between sprouting and blooming is much longer, so permitting the plant to develop the meaty root mass utilised by man
In these cases, as in many others which are empirically admitted but not yet scientifically proven, it could be affirmed that the period of time between new and full moon is a favourable one for reproduction, while the period between the full and new moons would be favourable to vegetative growth"

The main environmental factor triggering flowering is the length of the night, (a form of photoperiodism). Plant photoperiodic processes are perfectly capable of responding to light levels much lower than those experienced at full moon, so it would be surprising if plants did not respond to the phases of the moon.
If the moon can affect the flowering times of plants, then the distinction between "above ground plants" and "below ground plants", makes more sense: in the case of "below ground crops" (onions, carrots, turnips etc.) flowering is usually undesirable; but this is not the case with many "above ground crops" such as sweetcorn and beans (lettuce is one of many exceptions).
Azzi tested this with onions ("Effect of the moon on the development of the onion" La Meteorologia Practica An.17, No.6 Perugia 1936) and concluded that

"Sowing with a waning moon, and thus acting in such a way that the interval from sowing to germination aproximately coincides with a new moon, the formation of the reproductive organs is considerably retarded or put off, while the bulbs tend to reach a considerable size."

Azzi admits that this is not conclusive, and I am certainly not satisfied with the small sample size (10 plants grown over two years). There does not appear to be sufficient compensation for the weather either: Onion bulbs planted a month apart, in spring, could be subject to completely different weather conditions. If anyone knows of any more recent work on this subject, please
E-Mail me.[top]

Another scientific explanation

I recently watched a series on BBC called "Supernatural". One program talked about the influence of the moon on plants and animals, and claimed (among other things) that moon planting could improve potato yields. Their explanation was that plants and animals consist mostly of water, and so are subject to the tides. I had heard this before, as an explanation for all kinds of astrological phenomena, and I always found it rather unconvincing. No sources were quoted on the program, so I e-mailed the producer to ask where I could look for more information. He replied to say that most of the information came from personal communications with the scientists involved (in other words it had probably never been published, or if it had, the program makers had not read the appropriate books or papers). He did point me towards a number of authors, but didn't give clear references. Some I have been able to find, others not. Here is what I have managed to read so far:

The diameters of tree trunks fluctuate with the phase of the moon (the study looked at Spruce - the same tree which
Boots climbed to heaven). The authors compared this to the changes in water level in wells, and the ebb and flow of springs, in response to the tides. They concluded that the "moon is influencing the flow of water between different parts of the tree" [9]. The paper also quoted work showing that germination and initial growth of plants is affected by the phase of the moon by E.Zurcher (available at -Zurcher E.(1992) Journal Forestier Suisse 143 951-966), and a review of similar studies on 600 plant and animal species (Endres, K.P. & Schad, W. Biologie des Mondes Mondperiodik und lebensrhythmen, S.Hirzel Verlag Stuttgart/Leipzig, 1997). Unfortunately I haven't been able to get hold of this last reference, let alone translate it (languages aren't my strong point).

The claim that sap movement in trees is governed by the moon was not new C.F.C.Beeson made similar claims as early as 1946 [14], but denied that this was of any significance in forestry. His article was part of a review of literature on the moon's influence on plants, which was fairly sceptical. Beeson commented that this subject goes in and out of fashion periodically (as do many controversial areas of study), but the majority of studies find no correlation between the moon's phases and plant growth. He did draw attention to a study by Kolisko L. entitled "The moon and the growth of plants" (1936), which seemed to provide the best evidence. Kolisko found that wheat growth was greatest at the time of full moon, and in particular, the Easter full moon (I think this may be relevant to the page about Lunar Calendars).
H.S.Burr observed changes in the electrical potentials of trees (measured by putting electrodes 1.5m apart in the cambium), in 1945, which were attributed to changes in sap flow. It could simply have been that expansion of the trunks moved the electrodes further apart. (Diurnal potentials in the maple tree Yale J. Biol.Med. 17 727)

Frank A.Brown wrote several papers on the moon and plant growth. I managed to find one that he wrote, claiming that water uptake by bean seeds peaked 4 times every lunar month, around the time of full moon, new moon and the quarters.[15]. Harry S.Truman once said: "if you can't convince 'em, confuse em". I think this sums up Brown's approach to writing papers. The paper I read contained statements like:

"earlier evidence (Brown and Chow, 1973) had suggested that under some circumstances beans in closely apposed vessels mutually induced one another to adopt opposite signs of correlation with subtle geophysical variations, and under other circumstances the same sign"
What I think he is saying is that if the beans are too close together, the experiment doesn't work. (O.K. I admit it, these pages are not always very coherent and I have been accused of using too many long words, but I don't do it on purpose, honest!) His experiment also seemed to be unnecessarily complicated, requiring rotating electromagnets suspended over the beans, and beans arranged in rows aligned to points of the compass. It would be quite hard to repeat. Brown also wrote a number of papers on lunar rhythms in animals

M.G.Maw[17] looked at stem elongation rates in Galanthus nivalis (snowdrop), Corydalis cava (climbing corydalis), Anemone nemorosa (Wood anemone), Symphytum tuberosum (tuberous comfrey), Allium ursinum (Ramsons wild garlic), Aegopodium podagraria (ground elder) and Campanula rapunculoides (a sort of bellflower). Snowdrop grew fastest 5 days before the full moon, climbing corydalis at the second quarter, Wood anemone had a 7.3 day growth rhythm in phase with the moons quarters, comfrey's growth peaked at the second quarter, ramsons peaked at new moon, ground elder at full moon, and bellflower at the second quarter. The statistics and method seemed a little bit dubious to me:
Abrami sampled 3 or 4 plants of each species, but only presents results from the plant which "most closely approximated mean population growth and phenological stages". Consequently the statistics were too complicated for me to understand.
I was also recommended to read work by T.M.Lai (1976) and "Goldsworthy's ideas on electromagnetic detection in plants" (wasn't he the cop who plugged his pot plant into a lie detector?) I haven't managed to find anything by these people yet. All this has made me rather more sceptical about some of the things I watch on TV. [top]

Biodynamic Lunar Planting

Biodynamic farmers believe that planting and other agricultural activities should be planned according to the zodiac sign which the moon is in, but consider the phase of the moon to be unimportant (the moon passes through all 12 zodiac signs every lunar month. The new moon will be in the same sign as the sun each month). In essence they believe that leaf crops should be planted when the moon is in a water sign (Cancer, Scorpio or Pisces), fruit and seed crops when the moon is in a fire sign (Leo, Sagittarius or Aries), flower crops when the moon is in an air sign (Aquarius, Gemini or Libra) and root crops when the moon is in an earth sign (Taurus, Virgo or Capricorn). Eclipses and other unlucky days are avoided . Maria and Matthias Thun have produced some excellent scientific research on this subject. If you want to know more about this subject, I would strongly recommend Planting by the moon: A gardeners calendar by Nick Kollerstrom, published yearly by prospect books. It can be obtained from the "Planting by the Moon" website (link below)

Yet another scientific explanation

Lunar cycles can influence the activity, behaviour and breeding of animals (click
here for more on this). Plants are vulnerable in the first few days after germination, planting at a phase of the moon when pests are active could reduce the yield. The Malayan black rice bug is a serious pest, and seems to be caught more in light traps at full moon [10]. Gerbils in the Negev desert forage for food most at new moon, when they are less at risk from owls [11]. It seems likely to me that mice and rats (which can eat a lot of newly planted seed) might do the same. [top]


I approached this subject initially as a benign sceptic, experimented a little, compared some folklore traditions, chased journalists for scientific references and sifted some hard science out of a morass of junk science, rumour and hokum.

I am now fairly sure from my own experience gardening that the cycles of the moon are significant factor in plant growth (and I am 100% sure after many moonlit winter nights spent parting my donkey from her swain that the cycles of the moon significantly affects animal behaviour!) "Significant" here means statistically significant, it doesn't mean "big" and it doesn't mean "most important".

The effect of lunar cycles on planting may be an experimental artefact: wild plants drop their seeds when they are ripe and the seeds lie in the soil for long periods until conditions (temperature, moisture primarily but also possibly cosmic cycles.) are right. Wild seeds have mechanisms to prevent germination when conditions are not optimal. In contrast, cultivated plants often have seeds which germinate as soon as they get wet. Farmers have bred out germination inhibitors from their seeds, because under the artificial conditions of the field or garden, seeds must germinate fast before weeds smother them. Consequently crop plants in practice often germinate under conditions which are less than optimal, and choosing the right time to plant is crucial.

The choice of planting date is governed by a number of factors: The solar cycle is important. For instance, frost sensitive plants should not be planted or transplanted out until the last danger of frost has passed. The last frost date is primarily determined by the solar cycle, although the moon has small effects on the weather. I currently live in a continental climate (Bulgaria). Previously I lived in a maritime climate (Britain). In a continental climate. Summers are very hot and dry and winters are very cold and wet. The seasons change sharply and spring and autumn are brief. In a maritime climate all seasons are wet and mild in comparison. In a maritime climate, there is a lot of flexibility in the garden year. In a continental climate, the solar cycle is crucial: There is a short window of opportunity for planting each crop in spring: Too early and the cold will kill young seedlings, Too late and the sun will scorch them. The clay soil where I live can only be dug in a warm dry spell in early spring. If it is dug wet it compacts. If dug too late, the seedlings get killed by drought (I get around this problem by zero /minimal till gardening, but most gardeners here do not).

The evidence shows that lunar planting has a significant benefit to crops. In other words, crops planted according to the biodynamic lunar calendar sometimes grow better than those planted on other dates, sometimes they grow as well as those planted on other dates, and sometimes they grow less well than crops planted on other dates. Overall though, seeds planted according to the lunar calendar grow better than those planted on other days more often than would be expected by chance. In science, an effect that could only happen by chance 1 time in 20 is considered statistically significant (although odds of 1 in 100 are preferred). Scientists accept that this means they are wrong 1 time out of 20.

The lunar cycle is a factor to be considered in planting, transplanting and harvesting crops, but many people seem to think that it is the only factor to consider. I have heard of tomatoes left on the vine after frost, because "the moon was not right for harvesting". Bare root trees planted in spring when they were already making leaves, because of the phase of the moon. In both cases, the solar cycle was completely ignored.

Timing of agriculture needs to be timed according to both solar and lunar cycles, and also consider the weather, which is influenced by both solar and lunar cycles, but
integrating these cycles has been a headache for astronomers down the ages. Generally if a planting date is missed the next appropriate date will be around a week later in the biodynamic calendar. A weeks delay can have serious consequences in a climate like ours. It seems likely that the theoretical optimum planting or harvesting date may not be achieved in many cases.

Of all ideas in biodynamics, planting by the moon seems the most popular. However there is far more to biodynamic farming than just this. Biodynamic farms produce very high yields per unit area, and follow many practices not used in mainstream agriculture (use of herbal and homeopathic preparations, astrology etc.). The most important aspect of biodynamics IMO is it's strict adherence to organic principles and emphasis on system self sufficiency. Biodynamic farms cannot import large quantities of animal feed or manure from other farms, they must produce enough for their own needs through diversification. It is hard to tell if some biodynamic practices are useful and others ineffective, as they cannot be studied in isolation on a biodynamic farm. Biodynamic methods could force farmers into a level of focus on their land that could have indirect benefits. It is difficult for biodynamic farms to be very large, but small farms often produce more yield per hectare than larger farms, because the farmer is closer to the land, can observe subtle variations in soil, disease and pests etc. and devote more hours of labour per unit area than is possible on large farms.

* Rongo is a male name, but the Maoris also call the moon by the female name Hina or Sina. The ancient Babylonians also believed the moon to control the growth of crops. Their androgenous moon deity was called Sin[13]. [note, I've been told that the Maori alphabet has no letter S, so the Maori moon goddess probably wasn't ever called Sina. However, According to: "H is pronounced [ç] in some regions".If anyone can shed any light on this, please email me at untamedrootvegetable[at] ] [back]

**Recently, Randall Cerveny of Arizona State University has discovered that the temperature in the Arctic and Antarctic is 0.55 degrees C greater at full moon than at new moon. The moon also affects temperature in temperate latitudes, but not in the tropics. This may be due to transfer of heat by tidal effects on wind patterns, distortions of the earth's magnetic field by the moon, lunar effects on meteoric dust or simply the reflection of sunlight off the moon onto the earth. Others have commented that the earth is slightly closer to the sun at full moon, and that this may also play a part. The moon's cycle has also been implicated in other climatic effects. [4][5][6] . [back]

Links to other sites on the web:

Nature and Weather lore
Internet Classics Archive
For all the works of Aristotle and other classical authors (no honestly, it's really interesting )
Moon planting
Dragon's Lunar gardening
Gothic Gardening: potpourri
Gothic Lunar Gardening
Lord Skyknight's Medieval Gardening Page

A Witches Garden Wiccan Lunar Gardening
Randy Cerveny's Page

Planting by the moon
The old farmer's almanac

Using moon as planting guide can boost harvest

The Witches Workshop
Really comprehensive stuff on lunar/astrological gardening + moon tables
BBC Supernatural Page
The mysterious Moonflower
Ipomoea alba: No lunar garden should be without one
Seeds for a moongarden
Herbs Unlimited: Moon Planting
This is an excellent series of pages which go into the scientific theories about the moon's effects on plants in far more detail than I have. It is also fully referenced (makes a change!)
Planting by the Moon
A British site, not to be confused with the American site of the same name.
Gardening by the moon monthly advice continually updated
Effect of seedling date on initial growth and development of naked oats (according to recommends of biocosmic calendar. Roman Sniady et al.
Met Roman years ago at an organic farming conference. This is one of his scientific papers

Lunar Influence: Understanding Chemical Variation and Seasonal Impacts on Botanicals

Astrologers garden of delights

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