Dear Modern Farmer,
I hate weeding. No matter how much I do it, the nasty things seem to keep coming back. What’s the best way to kill weeds without using herbicides?
-Jamie in Connecticut
Manjula and Orin Martin.
Photo By Stephanie Martin
Orin Martin: In organic systems the best and only way you control weeds is mechanically – knock ’em down with hoes or hand-weed them outta there. One initial way to do that is preemptively, before you plant. Anytime you work the soil, 10 or 15 days later there’ll be a flush of weeds that comes up. It’s guaranteed. So if you have a really bad weed situation, you can flush weeds out before planting: Plow, bed up, irrigate, knock the weeds out as soon as they start coming up, and then plant. Especially if you have heavy weed pressure I’d recommend doing that a few times before you plant.
Manjula Martin: Where do weeds even come from? And why won’t they leave us alone?
OM: There’s this thing called the weed seed bank reservoir. It’s in the soil, it’s full of weed seeds, and it has an endless supply. And I mean endless. It’s crazy. Common weeds like lamb’s quarter, amaranth, and purslane have seeds than can lie dormant in the soil for 40 to 80 years and come up over time.
Not to get too anthropomorphic, but weeds are smart. Some are windblown, like dandelions. Some are designed to stick to mammalian fur, or in the case of humans, our socks. They’re inventive and ingenious in their strategies for dispersal. They’re metabolic opportunists, they use resources better other plants. And they live in the soil. So when the conditions are at all good or the soil is activated – a.k.a., when you garden – they’ll grow. When you cultivate, you aerate the soil, allow light in, water the soil – any of those things stimulate growth. With amaranth, or pig weed, as little white light as the glow of the full moon will activate germination. So no other factors considered, at least once a month those seeds are gonna germinate.
MM: This is getting a little spooky. I’m picturing this army of smart, strong weeds lying in wait beneath us, and now you’re telling me there are werewolf weeds?
Compared to weeds, cultivated plants are wusses. Weeds are smarter and stronger, and they’re coming to get your cute little butter lettuces.
OM: Yeah, well, it is a little spooky. Weeds are simply better at using resources than cultivated plants. By comparison, cultivated plants are wusses. Weeds are smarter and stronger, and they’re coming to get your cute little butter lettuces…
MM: Dun dun dunnnn… . So, we can’t do much about the seed bank. How else can we minimize the presence of weeds in the garden?
OM: Well you can keep yourself from contributing more weeds. Don’t let weeds go to seed. They germinate quickly, they grow big, they mature and set seeds early in the cycle. So don’t let ’em. Knock ’em out. This includes compost – if weeds haven’t gone to seed, they can be a good source of nutrients to cycle through a compost pile. But make sure they haven’t gone to seed. Once they’re there, they’re in there for the long haul. With something like poison hemlock, if it hasn’t gone to seed, it’s fine, but if it’s gone to seed it’s the end of your garden as you know it. Of course, the other way to minimize weeds is to weed using hoes or your own two hands.
MM: Here’s a sentence I never thought I’d say to my dad: Let’s talk about hoes. What do you recommend?
OM: Yes! Hoes are great. For early-stage weeds, my favorite tool is a collinear hoe. It’s got a narrow, very sharp blade and it’s made to be used standing up. With this hoe, you can get the weeds at the thread stage – when they’re 2 to 3 days away from breaking the surface, if you poke under the soil you’ll see this little white thread of a stem. And you can just move very lightly through the soil with this hoe – it’s not an old fashioned chopping hoe. It doesn’t disturb the soil too much.
There’s this amazing video on YouTube of Eliot Coleman using a collinear hoe. Of course, you may think it’s a little boring to watch an old dude weeding, but it’s so great! It looks easy, but he has such skill – you and I couldn’t do that as well. We’d knock down all those little lettuce plants.
The next step up would be a hula hoe or stirrup hoe. This hoe moves back and forth and gets the weed out in the next stage of growth, but it roughs up the soil a little. It’s a bit more disruptive but it works.
If you have to use one of those old-fashioned chopping hoes, you’ve probably waited too long. You gotta do it, of course, but it sucks.
One of the frustrations of using any tool is you can’t really get where you need it – the base of the plant – because you’ll knock the plant down. This is where you have to just get in there with your hands. If you have a loamy soil, you can just literally massage the earth – get down in there. That’s probably more effective than using any tool. They also have short-handled versions of those colinear hoes.
MM: We should mention that there are some deservedly negative associations with short-handled hoes. In 1975 the farm workers rights movement successfully got California to outlaw the use of the short-handled hoe – el cortito – because it caused debilitating pain and injury for farm workers.
OM: Yeah, and it was brutal. But in this context, if you’re a home gardener or small-scale farmers – you’re doing this by choice, so, you know… A short-handled hoe, when used judiciously, can be a valuable aid.
MM: So, how can a gardener keep on top of weeding? Are you ever “done”?
OM: No. But you can play an offensive game. And put it in your schedule. At the Chadwick garden, every Thursday morning, we go out and deal with weeds in a preemptive way. If you lock in time on the calendar, it gets done. Don’t let it lag.
It’s not really the best practice in terms of personal safety or fire safety, but sure – if fire’s your thing, go for it. This is a war.
You can also think of weeding by hand as a better way to know what’s going on your garden. When you get down in the ground and you’re weeding, you’re in the soil, you’re looking at the whole system. So you can have all these great insights about other aspects of the garden system and see how things are and aren’t doing. As my departed friend, accomplished artist and acclaimed garden-maker Hardy Hansen used to say about gardeners, “Orin, you can tell the good ones. The good ones aren’t afraid to get down on their hands and knees and weed. They love it.” Weeding by hand is kind of a badge of courage for gardeners.
MM: I actually love weeding by hand. I just sit down and Zen out. Meditate or whatever.
OM: Sure, it can be Zen, and it can be torture. But there’s this feeling, at the end of the row, at the end of the bed: you turn around and look and bam! You did it. You can see the progress you’ve made.
MM: Or if you’re less Zen, you can just get a propane backpack flamer and set the damn things on fire.
OM: Yeah, that’s not really the best practice in terms of personal safety or fire safety, but sure – if fire’s your thing, go for it. This is a war. Pick your weapons and get on the offensive.
Want more growing advice? Check out all of Orin and Manjula’s columns here.