Companion Planting

I've heard a lot about companion planting over the years, everybody knows about sticking onions and carrots together and placing marigolds near tomatoes and I believe roses should be planted at the end of rows of grapes, but perhaps that's just to make them look pretty. Anyway, this year Kylie and I (i.e. Kylie) decided to give it a bit of a go.

Companion cropping can be described as the establishment of two or more plant species in close proximity so that some benefit is derived, like pest control or higher yield. It is related to intercropping and biodiversity which brings its own benefits. At the other extreme, single crops are notoriously susceptible to pests and disease (think potato famine).

We are starting with the onions as we know they work so they'll be a center piece of our companioning strategy. We were also going through the seed catalogues and found pyrethrum - it must be useful for something as it's used in organic pesticides so we bought a packet of that and I'm sure we've got marigold seeds somewhere too. I've had a bit of a scout around the net and there's plenty there but mostly it ends up with a table such as the one below.
The theory is that companion plants either:

• lure pests away;
• fix nitrogen for the other plants;
• emit chemicals to keep pests away;
• physically confuse or protect from pests;
• provide protection from sun and wind create a habitat for beneficial predators;
• provide diversity as most pests target a limited number of plant species (i.e. they can't eat them all).

Basically I'll let you know how it's going or if we've given up as the year progresses. Feel free to drop by B31 to have a chat - any companionly suggestions will be gratefully taken on board.