|The peas don't like growing with the onions, but why??|
Time for a bit of google research and I found a few interesting articles.....
Is Companion Planting Scientific?
The Myth of Companion Planting
The Art of Companion Planting
I can see that the reasons that companion planting may work, are varied and include:
- alleopathic interactions (both good and bad)
- confusing pests
- preventing the spread of diseases
- enhancing environmental conditions for growth (mostly about shading young seedlings with wide-leaved plants)
|Zucchinis and corn are supposed to like growing together, but can you see the corn?|
Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial (positive allelopathy) or detrimental (negative allelopathy) effects on the target organisms- WikipediaYou really need to know the alleopathic interactions of each plant to know which can be planted together, and maybe that's why I had a problem with the peas next to the onions, but it seems that most of the research in this area has been targeted, as usual, at commercial applications for allelopathy - using the chemicals to develop herbicides. Its so frustrating that this research effort is wasted when they could be working out how to grow vegetables in organic gardens/larger scale farms more efficiently! Although I guess its pretty difficult to design an objective study of plant alllelopathy, so I should just use the associations that have been developed over the years based on experience and see what does work for me.
My next problem is finding a system that I want to follow. As this post found out after comparing several different companion planting guides, they don't all agree! They recommended that you at least consider the plants that are consistently reported to not grow well together and try to avoid those combinations, which includes peas and onions (damn!). They have compiled a summary of several commonly used guides to assist. There is also a summary table (which even includes some reasons for bad neighbours, I like it!!!) on this post from Sustainable Gardening Australia, which I think will be useful. I have copied it into a word doc, deleted the veges that I don't usually grow and printed it out for easy reference in future (I almost need to laminate it and put it on the garden gate so I remember to use it!).
If you are interested in reading about other potential gardening myths, Linda Chalker-Scott has reviewed a number of them, with some interesting and well-researched articles on her website.
Do you use companion planting in your garden? Does it work for you?