Weed Control – or Loss of Control – in Mid-Summer
This morning I got an email from a dear friend who is farming for the first year on new land. With no time for her usual warmth, she simply wrote: Drowning in hand weeding and can't keep up. Tool bar I got this year isn't really working on my International Harvester. Do you think this looks like a good move or a stupid move [referring to an Allis G cultivating tractor that was for sale] - would have to take out another loan, so don't want to make any hasty moves.
All of our farms and gardens are cresting into July madness, where food crops and weeds collide in a decisive battle of wills. Gone are the early May days when nicely transplanted rows of green and red lettuce were the only colors freckling the field, where the soil was a cakey brown simply waiting for the carrot seeds to gracefully raise their cotyledons towards the sunlight. Now, with these solsticey-long days and moist, warm soils, conditions are perfect for weed growth. Any bare soil is quickly covered in a haze of amaranth, crab grass, and, if you are unlucky (but normal), galinsoga. What food-growing person doesn’t feel like they want a magic bullet to combat these rampantly growing weeds? Taking out a loan for a new cultivating tractor, or even briefly contemplating the wonders of herbicides, is where our brains dwell this time of year, especially as the window of opportunity to control the weeds closes in.
Which brings me back around to that endlessly troubling question about how do you control weeds on an organic vegetable farm? Our farm manages 55 acres of land organically, which has forced us to manage weeds with a few broad guiding principles:
- We try to manage our weeds as a population with the long-term weed seed bank in mind.
- We try to use the appropriate mechanical cultivation tools for our scale and we ALWAYS precede hand weeding with some form of mechanical cultivation.
- We acknowledge that we are never going to eliminate 100% of our weeds (although we do aspire to be the Nordells!) and we try to humbly maintain happy lives nonetheless.
- In 2011, we had onions in one section of a field which we grew in plastic mulch and kept relatively clean of weeds. We harvested the onions, pulled up the plastic, and planted a solid fall/winter cover crop. Very few weeds set seed, leaving us with a clean field going into 2012. Knowing that we had low weed pressure in this field, we planned to seed our salad mix there this season, which we direct seed and like to keep absolutely weed free. Prior to planting the salad mix, we prepare several beds in advance by shallowly basket weeding them in order to disturb just the top ½ inch of soil and force weeds to germinate. When we seed the salad greens, we flame the weeds, cover the bed with re-may, and return to harvest in a couple of weeks from a pretty weed-free bed. The key to our salad mix luck is keeping several beds ahead of ourselves with the basket weeding, allowing weeds to germinate and then die in advance of planting.
- Winter squash is a big acreage crop for us. We grow most of it from transplants, and count on it establishing itself quickly, vigorously, and shading out any weed competition about a month after transplanting date. We simply can’t afford the time or money to do more than a couple of tractor cultivations and one quick hoeing pass with the crew through the field before the canopy of squash leaves shades the soil underneath. If we miss our opportunity to get through the squash before it’s too late, we suffer from an ugly, weedy squash field. As of this article, we are just finishing our one and only hoeing trip through our two acres of squash; after that, we cross our fingers and hope we did a thorough job.
Thank you.