Weeds and pests in organic farming have been more than simple foes--they have also shown us a complexity to the symbiotic nature of growing things that we did not know existed. Take weeds, for instance. In California, we had less weed pressure in the summer when native plants are actually dormant (because of lack of rain and too much blazing heat). So when we came to Ohio, we were unprepared for the aggressive, quick-growing capacity of weeds. We lost many first beds and crops to this nemesis. It was our first challenge and we tried our best to educate ourselves on everybody's best method of fighting against weeds. In the end, we chose the mulched bed system--in which less tilling of the soil and more building up of beneficial microbes have been key to turning our soil around. But in our studies we have learned a curious thing: these weeds know something we don't and show us above ground what they sense underground. Take the dandelion for instance. Where there is lack of calcium in the soil, the dandelion will appear, and with their deep taproot pull up calcium to the topsoil in order to restore balance. This is true for many of our common weeds, who, at one glance are ugly and intruding, but at another are attempting to indicate imbalance and correct the growing conditions! Who knew?
As for the insect world--I understood there were beneficial and non-beneficial bugs. (Actually, I had a hard time with that. I can't stand any bugs.) But the good ones are called "beneficial insects," like ladybugs, spiders, and praying mantis; and the bad ones are called "pests," like aphids, Japanese beetles, blister beetles, etc. While I still can't think of a good reason to like pests, I've learned another curious thing: that when a plant is sickly, it emits a "signal" that lets pests know of its weakness, and pests show up from miles around just to attack that plant and do away with it. This also indicates poor soil, and saves us from eating from a plant that does not produce optimum vegetables.
While that may be all I know where weeds and pests are concerned (Jeff knows WAY more) I am still amazed at what I've learned--especially about the rightness of NOT spraying chemicals to kill off weeds and pests. They are trying to communicate to us about the intricacies of the unknown, unseen biological world...which indicates to me we have a really smart, Green-Thumb of a Creator God.