The Power Of Polyculture
I was never really convinced that this had a real impact on productivity until I tried it. The idea is that a large group of the one plant makes it easier for pests for that plant to thrive. You've grown them a food farm of their own. But can grouping many species together really make much difference? Yes it can. And here's why I believe so...
Canopies - when you have a patch of all plants at the same width and height, you lack one of the most advantageous systems in ecology. The canopy. Having a canopy can trap up to 80% more moisture in the local microclimate helping all plants within it to thrive. Condensation forms on the leaves of shaded plants and eventually drips to ground level like irrigation.
Diversity of insect life - when you get a range of plants you get their range of residents as well. The more diverse the resident population the more likely it will be that one will keep the other in check preventing plagues of any one pest. We've seen this with our citrus plantings. Every now and gain we will see an outbreak of aphids on the citrus plants. When I say an outbreak, I mean whole stalks covered in a thick layer of them. Thousands, if not millions of them. It's enough to wipe out the entire yard. Yet as soon as these aphids appear like this it is only a matter of days before the surrounding population of lady birds moves in, lays a heap of eggs and their larvae wipe out the aphids. Without the umbellifer plants in the garden we would not have a lady bird nursery present that naturally and effectively keep the aphids from destroying our garden.
Hiding the crops - when you have a great mix of plants in the one section the garden takes on a wild aspect and replicates natures own defense against predation of crops. Simply being out of sight. Whether the predator is a possum, bird or grub, they have to find the plant first. A nice large patch of lettuces is an open invitation to snails and slugs, yet we have hundreds of Cos lettuces self seeding in the garden at all tmes of the year and never have a problem with these pests at all. Mostly we have to go foraging for the lettuces, tomatoes and other goodies because they have sprung up under something else. What a treasure it is for us to find, also that it is not been found by anyone else.
When I first started gardening here a year ago, The temptation was to plant patches of monocrops, and each time they failed or had limited success due to predation. Once I started scaterring mixed seed about everything became a lot more productive. The latest crop is a mix of carrot and buckwheat, one was sown over the other. So far, no carrot fly and the carrots are almost at harvestable stage.