If you can imagine what might happen to a whole field of cabbages, growing as far as you can see all around you, should a pathogen to which that particular type of cabbage is particularly vulnerable happen to strike, then you will quickly be able to realise the value of a diverse field. When the cabbage has, say, origanum and spring onions as neighbours and the next large plant in the planting plan is a brinjal, rather than another cabbage, then there is a barrier between our first sick cabbage and all the others of its kind in the planting plan. This means that although a pathogen might find its way onto one of your cabbages, that is not to say that your entire cabbage crop will be affected. In fact it is quite possible that some of the companion plants around these hypothetical cabbages vulnerable to infection may destroy the pathogen. Certainly other aspects of the bio dynamic system will be destroying pathogens and reducing the likelihood of infections. Not only is bio dynamic soil full of the most diverse array of micro organisms possible but the earthworms and associated microbes at work throughout the soil will be progressively removing or destroying pathogens as healthy germs are added to the soil. This diverse approach, addressing both microbes and macrobes is what creates the rock solid stable agricultural system that is bio dynamics. Building soil rather than depleting soil.should be the goal and diversity is what makes it possible. A diverse garden orfield, to put it simply, is worth far far more than the sum of itsparts.