Mabb, I'm not necessarily a proponent of one method over another. My practices are dictated purely and simply by a lack of growing space. If I have plants with vastly different requirements, I separate them as much as possible, even if in the same bed. If you have the space, rotate by all means, but the rotation system was designed, mainly, to overcome residual disease and/or deficiency problems. The ready availability these days of organic soil conditioners and improvers means you can renovate beds annually, overcoming those problems. For example, I've grown tomatoes in the same beds every year for more than a decade without the slightest problem.

Hi Mabb
From my perspective you need to understand several things for this to be successful...it works in nature...on the otherhand a garden setting is a long way from a natural setting...fences for example prevent a lot of air flow and make your garden prone to fungal attack
As far as soil pH goes ....most vegetables do pretty well in a general range of pH levels but do not do well in extreme pH soils....so you get leeks and onions doing well enough in the same soil as potatoes
In nature you find plants that have non airborne seeds having to grow in the space their parents did and that seems to work...I would suggest because the decomposed plant material stays on site and thus the nutrients in that are ready to supply the new generation of seedlings...a reason why I advocate sheet muching when ever one feels the compulsion to "weed"
I have also found that pests and diseases (seem) to be pretty well nonexistant when the flora is of greater diversity...it is much harder for pests to find and move from one host plant to the next in a "jungle" of diverse plant types
I think that the concern that some people have of weeds using water at the expense of vegetables is also misplaced because I feel that evaporation levels are lower when the moisture is trapped under foliage (as in a rainforest) and the sunlight cannot reach the soil (where it kills off soil micro-organisms to the detrement of soil fertility)
The greater energy conversion from sunlight to plant matter means an increase in soil fertility over an extended period
Fukuoka suggests that soils do change over time (in his experience it takes about 10yrs.) and that one finds a change in the success rates of some plants when the soil has had one type of plant in a succession in one area...this can be beneficial of course but when diversity is maximised and mass is also maximised at the same time you can only gain
The greatest problems I can envisage is that of toxic root exudates which some plants have and also that of autotoxicity which occasionally occurs
It all sure beats buying in your fertility
cheers
Peter

Hi Mabb.
I cant remember but I may have posted about my bed of Parsley, Asparagus, Capsicums, Basil and Spring Onions that has thrived and shown no signs of disease or pest attack. I have been sceptical about mixed plantings and their benefits, but this planting is proof to me that it works. I had 5 tomatoes in pots growing near this bed, and one of them is still going and producing fruit like mad in this extended summer down here. Makes me think that mixed plantings of the right types will really work.
What really got me started was that I wanted a bed of asparagus and my wife didnt. So, I went ahead and planted the crowns and then the parsley, capsicums etc, and she was happy. Now we are happy, and so it seems are the plants.

Hello Lol,
I look on rotations as a means of addressing the problems of monoculture, no monoculture, no need to rotate. There are advantages in growing legumes (inoculated if the right bacteria isn't present) before vegies with a higher nitrogen requirement and a few other things but it's not important, mulch brings most of the needed nutrients.

The argument that a a jumbled planting ranter than planting in straight lines reduces pest worries is quite valid. If you plant all your lettuces for example, in a straight line and pests eat a couple you notice it and worry. You don't notice the few pests eat in a jumbled planting so don't worry, much better-
Neil

Jumbled up works for me. I do look out, though, that plants with the same watering requirements are grouped together. No point in planting vegies amongst my herb garden. Don't want to shock my plants with water in summer. They are not used to that.

There are quite a lot of herbs scattered about/around the vegie garden, though. They are there for the vegies' entertainment.

I'm a rotatian girl, but not fanatically so. I have a six bed system but only 5 beds so tend to add the other things in wherever I can. I think there are benefits to both approaches & you should just follow whichever you fancy!