Organic gardening was once labelled 'all muck and magic' but now as we start to understand the interactions of our soil's ecology it becomes more a matter of 'muck and management'. Practices once considered magic such as companion planting have now been shown to give yield increases of about a fifth in field trials. We now begin to appreciate the value of trace elements, the importance of humus and the role of mycorrhizal fungii; all of which would sound like magic to any gardener from before 1850, and quite a few of 1950 I suspect.

The commonest bit of 'magic' practised by gardeners (other than touching wood?) is Lunar or astrological planting. Now I must here admit to my position which is not a sceptical one but more heretical. I believe that there is an effect but I have no truck with all the woolly minded practices that have grown up around it.

Now there are some of us who are neither credulous nor gullible and can see there is just about a logical reason for not walking under a ladder, and even for not walking on the cracks in pavements which may once have been a dangerous footing. Many such magical dictums are not magic but good observation dressed up in other clothes. However it is important to find out the difference.

There is no question of the sun affecting our plants. It does! And not just in the so obvious ones. Plants do not respond to sunlight in one simple way of growing in light and not in dark, or even just in a proportional way of more light more growth. Many plants 'measure' the length of day (rather it seems they measure the dark) and whether it is increasing or decreasing, and change their growth accordingly. Indeed experiments with tomatoes show they can be grown under continuous light but are not happy; like us they need a period of complete dark for a 'sleep'. (A street or security light nearby could possibly affect a crop of tomatoes, or other day length sensitive plants) And it turns out that some plants can be easily fooled. Growing them under lights they do not understand that a short burst of bright light is not another day gone by and thus come into flower sooner. Now with some known solar effects it seems likely there could be others so it should not be surprising if the weird lighting of an eclipse may not trigger some change in plants, perhaps a total one initiating a premature flowering. However I noticed nothing remarkable after recent partial eclipses.

However I am more sanguine as to the possible effects of the moon. The light is nowhere near as bright as daylight but it is quite enough to see by! Thus plants can be assumed to respond, and it varies rhythmically and has been doing so for millions of years so it seems logical it will have become incorporated in many plant's measuring schemes. Certainly many marine organisms are synchronised to the full moon. Moon light is also very different to day light as it is polarised which means that it is a strongly directional signal. In fact one would be surprised to find that the plant world had not made some use of this feature in their environment!

However when one starts to discuss the Moon's effects most of the justification centres around water, after all, as is always pointed out, the moon affects the tides. Indeed and the water under the ground and the ground itself which moves up and down by many inches in just the same way as the seas! But more importantly; the moon affects rain, there is not much doubt that rainfall is cyclical on an annual basis, but in many places it is also claimed to be cyclical on a monthly lunar basis.

Well that doesn't seem so unlikely but if the water table or the rainfall was such an important factor then there would be little point sowing or planting by the moon in the garden as one good watering could eliminate almost every such effect, and under cover in pots all such influences are completely eliminated anyway.

Of course it may be they are responding to the direct variation in gravity; most plants must be sensitive to gravity, how else could they grow as upright on a slope as on the flat. The moon is pulling at every thing and so it's gravity could be used by plants as much as polarised light to determine in which direction or when to grow. And this brings us on to other masses, the planets may be far away, and other suns even further, none the less just as we can see their light with the naked eye, their gravity fields interact with ours even if only on a sub-microscopic scale. Yet it is at that same sub-microscopic scale that most life processes work so again I would not be surprised that life has utilised these signals for it's own purposes.

Then there are magnetic fields. These undoubtedly do change the rate of some chemical reactions and can even make flames burn more efficiently. Very large numbers of people claim some relief from pain with magnetic bracelets and also apparently so do animals! So it seems reasonable to assume they must affect the plant world to some extent. Some experimenters have tried using magnets on plants with varying results. One early idea was burying railway lines under rows of crops to enhance the Earth's natural lines of force. Today electronic equivalents are on sale -though I've not yet seen one in use.

None the less I was careful when I made my garden plan to align all my forty vegetable beds north south. Now this makes sense with the beds not shading one another and any rows on the beds get equal day light length on either side. But I aligned the beds magnetically and not by the sun as there are several degrees of difference and this has a big theoretical effect on the efficiency of gathering magnetic lines without much changing the light distribution.

Similarly there are increases from the supports for tall crops on some beds which are recycled steel scaffolding poles. But the whole lot is surrounded by runs of wires carrying soft fruit and wire netting to keep out my hens. This is what is termed a Faraday screen and reduces the electromagnetic influences to some extent, perhaps shielding my crops from pernicious mobile phone conversations. and stopping them tuning in to Eastenders. Indeed it becomes impossible to predict what departures from the completely natural environment this modern clutter all entails and actually whether any of it is of benefit or to the contrary.

So that is where we come back to experiment. I have compared the speed of ripening of two fruits; the winner with a magnet on it's stem -but did I subconsciously choose the most likely. And did a magnetic bracelet heal a sick plan? Not as well as good practice! But it did seem to increase the speed of rooting, or then again did it? The problem is that such experiments are hard to make really 'blind'. Searchers only search for what they search for.

But worse than this is the variability of the outcomes depending on who does the experiment. When I conducted a mass experiment on lunar planting on the radio the end result was totally conclusive; some people found one of the two days really good and the other poorer, and other people were as convinced they had found the opposite. The experiment was partially blind as the days chosen were equivalently astrologically poor. But none the less the outcomes were very different when tested on the ground, but not predictably as it varied more by the person than the day.

A similar trial I have conducted several times is to sow a few seeds every day, day after day, in the same way and same conditions. It is amazing some days you get every seedling emerges, another day none, another day three batches all come together. It seems to me although you may sow when you like the seeds wait till the right day to germinate or emerge anyway.

In another classic trial series, the germinating cress problem, the method is simple. Three pans of cress are started off, labelled on their bottom: A, B & C, and shuffled well before commencing. Each day they are shuffled when watered and A is prayed for and encouraged, B is cursed and cussed and C is thought of as control. Two things invariably happen; the first and most common is 'accident' causing the experiment to abort and secondly it either works magnificently well for some people, or not at all for others.

The very act of experimenting appears to influence the outcome, and now we are deep into Heisenberg's uncertainty principle of sub-atomic interaction. But even if you have what seems to be hard statistical evidence in a double blind trial with different folk it may not be evidence of any real cause or connection; there are parallels. For examples; in one large US city the cases of rape per week exactly follows the same graph as the sales of ice-cream but as yet not even the most rabid politician has suggested outlawing the latter for it's evil influence. Or you do get the right observation but draw the wrong conclusion. For example; in the dark ages great efforts would be made to recover weapons which had been used to make a wound in order to then clean them immaculately. The understanding being completely correct in everything except as to timing!

Primitive folk were incredibly observant, and had good memories, and were gullible and credulous. It is easy to see how some unforeseen side effects could become given magical overtones. Take the area where an animal was killed, the blood spilt and the next year the crops would grow better on that spot and quite noticeably so. Indeed I would expect the sacred groves of trees around sacrificial sites to have been amazingly luxuriant. And thus prone to soft growth and pests and thus honeydewed. Then after another sacrifice takes place, fresh blood and flesh attracts hordes of flies who also clean off the honeydew the trees appearing miraculously cleaned. (A dead rat did this for me in my polytunnel, the hatch of flies was uncomfortable but while they lived they cleaned my citrus trees up perfectly.)

Or daubing magic signs and symbols made of 'very home made ingredients' about the place could have attracted or fed some other creatures to do some apparently strange thing. I 'persuaded' ants in a coldframe to take my jam after I saw a nature film of tropical ants protecting a plant in return for nectar. I put jam on some peppers that every year always got aphids when they rested there which were then farmed by the ants. The ants found the jam and soon the aphids disappeared, I guess with plenty of sugars the ants wanted more protein.

So I can see how even the most outrageously bizarre ritual could actually have had some effect especially when it involved many ingredients. Indeed it is up to us to find the good seed in amongst the chaff. So next issue I will deal with even more exotic magic.