This post was prepared by Gary Martens of the South Eastman Transition Initiative.
It wasn’t so long ago that I looked forward to the new spring growth; the greening up of the world. Then it came on strong, nurtured by timely rains and the warm sun. Now, a few weeks later I am already thinking about stopping some of that growth. I hear lawn mowers cutting grass, and sprayers out in the fields. Garden hoes are quite silent but do provide a satisfying clunk as they cut off a thick dandelion root.
As I survey my beginning trees I see weeds filling in the spaces around the trees. The carrots seem so slow to establish compared to the lambsquarters, stinkweed and pigweed that form a carpet of unwanted green between the rows. Why is it that my beans are so slow to emerge and some of them have not emerged? I am going to plant again to fill in the vacant spots. Why is it that the weeds are abundant, need no help from me, start without watering and grow incredibly fast, covering the small domestic plants that need my assistance to make it in this world?
I think part of the reason for the extreme competitiveness of weeds is that we (homo sapiens) have, for the last ten thousand years tried to get rid of them. Because of this, they have then adapted to our methods and thus outwitted us. For example they have changed their appearance to look like our crop plants. A case in point is barnyard grass which resembled rice, yet looked different. Rice in Asia is intensively hand weeded, but people did not pull the barnyard grass that looked like rice, so the more barnyard grass looked like rice, the more likely it would survive the weeding and produce seed. So result is that in Asia, all barnyard grass now looks like rice and can not be distinguished from rice until it flowers. Then it is easy to identify but it is too late to do anything about it.
In larger fields where hand weeding is not practised, weeds are under different kinds of selection pressure. Some weeds adapt by starting early to finish their reproductive cycle before we even get onto the field. An example is the winter annual stinkweed. Other weeds wait till we have finished seeding and come up along with or just before the crop. An example is pigweed. The use of herbicides has also placed selection pressure on weeds and they have adapted by becoming resistant to the herbicides.
One of the reasons that I am switching much of my small farm to permaculture is that I am tired of fighting weeds. Of course, I still will have weeds but I won’t have as many annual weeds like wild oats, green foxtail, lambsquarters, and pigweed. I will however have more perennial weeds like dandelion, thistle and quackgrass. I hope to introduce the right animals at the right time to help me control those weeds.
We can reduce our weed problems by not allowing them to go to seed. That way if we garden the same plot for many years eventually the seed bank in the soil will decrease. Unfortunately, the wind will always bring some new weeds. We can also fill the spaces that weeds like to occupy before they get started. In a large field that means using higher seeding rates and intercropping; that is, planting more than one crop on a field at a time. There are now significant numbers of innovative farmers that are developing this new method of farming. Tannis and Derek Axten of Minton Saskatchewan have been recognized as Canada’s 2018 outstanding young farmers. They do not plant a single crop (monoculture) in a field anymore. They plant canola or mustard with peas, chickpeas with flax, and cereals with clover.
In the garden some people have become skilled at companion planting. For example you could plant beans and squash with your corn. This is the classic “three sisters” planting practised by indigenous peoples in North America for many thousands of years.
The basic principle in the fight against weeds is, don’t give them a place to grow. Fill the space yourself so that they can’t. You can do this with living plants as just described or you can use mulch to cover the ground to prevent or reduce the weeds in your garden. Mulch works especially well around transplants because they are already above the mulch and small weeds will not be able to get through a thick layer of mulch.
Check out this talk (download MP3 audio file) given by Colin Rosengren, Producer from Midale, SK at the Organic Day which was part of the Manitoba Ag Days in January.