Why farmers may want to keep, not kill, weeds

I know this is crazy
but Cornell University (probably with some grant)
has come out and said that weeds may be good
who knew?

http://www.futurity.org/weeds-pest-management-1295912-2/?utm_source=feedly&utm_medium=webfeeds

Why farmers may want to keep, not kill, weeds

“The benefits of weeds have been neglected. They’re often seen as undesirable, unwanted. We’re now beginning to quantify their benefits.”

This articles explains why a farmer would want to keep weeds.  A must read for everyone!

Duane, thank you for sharing.

My favorite part of the article:

"More weeds, more butterflies

One additional side benefit for having a few milkweed plants in a field of corn is that it serves as a breeding place and food source for monarch butterflies. As of late, monarch numbers are down, and the US Fish and Wildlife Service is evaluating a petition to have them protected under the Endangered Species Act."

It's not crazy at all. I haven't read the article yet, but I know what it's going to say.

Most organic farms are very very heavy on cultivation and the mentality that "all weeds are bad". This is incredibly stupid. Basically they are saying that bare ground is better, which anybody can tell you makes no sense.

The longer I farm, the less I weed. I do absolute minimum cultivation in the immediate vicinity of growing plants until they are able to out compete the "weeds". If there is no competition, I do not weed. For example, with carrots I let weeds sprout along with the carrots and then weed in the immediate vicinity only enough to let the carrots outgrow the weeds. It's a tricky balance because I want the weeds to help retain soil moisture and even shade the young carrots, but not directly compete so much. After a certain point the carrots are bigger than everything else and I need only weed the odd thing that gets out of control.

For other crops, which are sometimes very sensitive to weed pressure and competition (e.g. corn) I'll cultivate with a hoe but only within 1-2 inches of the plants I'm growing. I never weed at the sides of my field or in between rows. I use those weeds to provide shade where appropriate. The difference is very dramatic -- it keeps the soil cooler and reduces water loss very significantly. But the real kicker is this: pests. I don't have significant losses to pests any more. For example, flea beetles LOVE hot and dry, so with weeds around keeping the soil moister and cooler they go elsewhere. And with flowers and all kinds of native plants I have beneficial insects and pollinators like you would not believe. The result is partly that people think I'm not a very good farmer. They look at my fields and think I'm doing it wrong, when in fact I have reduced my labor very significantly and use NO pesticides of any kind, organic-approved or not. None.

I don't know how we got into this idea that we had to have a barren waste land to grow our food in. It makes no sense.

I don't know how we got into this idea that we had to have a barren waste land to grow our food in. It makes no sense.


It really has mirrored technological development, which has led to increasing  corporate influence.

The article really refers to IPM as it relates to juxtapostition of beneficial weed type plants within or near a planted crop, it certaintly does not refer to a lot of weeds in fields. Corn is not going to yield well to a economic threshold if allowed to compete with too many weeds.

Ray, yes absolutely, but it's more complicated. For one, corn is not going to yield well enough to be profitable for most small-scale farmers anyway. I don't know a single diversified farmer who makes money on corn. We only grow it because it rounds out the offerings, is tasty and is expected. I stopped because I was losing too much money and couldn't justify the water in a drought.

Typically farmers will nuke everything in sight and cultivate between rows and never question this. Now that I've read the article yeah, it doesn't go nearly as far as I've gone in my thinking. As I said I don't weed beyond the immediate "competition zone" or sometimes at all for many plants. So in the case of corn that is about a 2"-3" swath on either side. The conventional thinking of "we must maximize yield always" is really quite silly. There are many efficiencies to be gained by sacrificing a tiny amount of yield (sometimes none at all) to save in other ways.

I have saved myself so much time and money by having lots of weeds in the fields. I wish I had pictures, but now it's winter. This has literally become my approach and I urge everyone to re-examine their thinking about "weeds". To give another example: this past spring I grew lettuce such that from a distance you could not see the lettuce for the weeds. I never had to irrigate and yet my yield was exactly the same. The lettuce tasted better to boot because the soil was kept cool.

Eric Bee wrote: This has literally become my approach and I urge everyone to re-examine their thinking about "weeds". To give another example: this past spring I grew lettuce such that from a distance you could not see the lettuce for the weeds. I never had to irrigate and yet my yield was exactly the same. The lettuce tasted better to boot because the soil was kept cool.

Eric, you made two great posts and a great example of why keeping weeds helps.  And now that you have read the article you know it is about Pest Management.  It is about not using pesticides and giving the natural progression of pests a chance.

My example would be that we can't spray pesticides or even soap spray because we have a Butterfly Garden.  We do not want to kill the butterflies or their larva.  This year we had lots of bugs/pests that we have never had before. Some good and some bad. Lubber grasshoppers, aphids, praying mantis, solder beetles, false milkweed bug, lady bugs, bees, flies, and maybe wasps.  Some like aphids got eaten by the soldier beetles.  We had lots and lots of butterflies and we had Monarch butterflies and their larva.  Nature took its course.

From the article:
"The milkweed plants can harbor aphids (destructive sap-sucking flies) that produce a nectar food source for beneficial parasitic wasps Trichogramma.  The wasps, in turn, lay eggs inside the eggs of the European corn borer, killing the corn borer eggs—reducing damage to the crop.  ...

“It’s very important to recognize the benefits of all the species within the crop field—that includes both the crops and the weeds—not to mention cover crops. Weeds can offer ecosystem services, such as soil erosion protection and pollination services for the benefit of insects,” Averill says. “They can be part of a restorative cycle.”

I encourage everyone to read the article.  The article seems to give the imprecation that they are talking to/about the commercial farmers, I see it as something anyone who grows anything can learn from.

I did not mean to say "imprecation", instead I wanted to say "impression".  Spell check error.

Actually Anne, most of my point was that my practices weren't just about pest management and that this sort of thing should be thought of holistically. Yes, they are talking to commercial farmers. That may be why they tone down their recommendations. When I said up there that "I know what it's going to say" I knew it would be about pests but hoped it would go farther. I think home gardeners need to take this as a general principle and run with it. For a commercial farmer like me to adopt these practices, however, is pretty much unheard of.

Keeping weeds solved pretty much all of my pest problems and now that that balance has been restored I don't need to do much and never spray anything. But this is also an extension of my long-standing practice of using the weeds to help me solve other problems, such as as wind protection when it's cold and to keep soil moist and cool when it's hot. Another example: my english peas this year went about a month longer than usual because they were surrounded by weeds and they never got the powdery mildew that inevitably has happened once the weather starts getting hot and dry. In the past I've mulched with straw, but that has problems and does nothing for beneficials. On the pest side, this really is about providing ecosystems conducive to the natural balance, which is about 90% things that don't eat your crops and 10% things that are a real problem.

Two other general principles I've learned over the years about pests and restoring balance: 1. If you spray anything, even just soap, you kill everything. All that does is provide opportunistic pests a window to do their damage without much predation; 2. Where there are pests there are things that eat pests. I've learned to be patient because I know when I do see pest problems the predator insects are not far behind.

Eric Bee wrote:
The longer I farm, the less I weed. I do absolute minimum cultivation in the immediate vicinity of growing plants until they are able to out compete the "weeds". If there is no competition, I do not weed. For example, with carrots I let weeds sprout along with the carrots and then weed in the immediate vicinity only enough to let the carrots outgrow the weeds. It's a tricky balance because I want the weeds to help retain soil moisture and even shade the young carrots, but not directly compete so much. After a certain point the carrots are bigger than everything else and I need only weed the odd thing that gets out of control.  

The interesting thing I noticed this year is that carrots do better when they are following another crop. I discovered that more or less by accident (impatience). I seeded carrots and they didn't come up and didn't come up so I seeded it with lettuce again. Sure enough best carrot crop ever. The lettuce grew nicely and I harvested regularly the outer leaves. The carrots came up in between and I let them be. In fall, lettuce was done and I had the nicest crop of carrots in that spot!

Simone, I can never grow carrots without mulching them. My usual practice is to cover the whole row with a row cover. They simply will not germinate unless they are kept moist. Traditionally people would put down a board or even cardboard (which I've tried too). I'm guessing that your happy accident was just that the seeds where kept sufficiently moist -- this strikes me as wholly consistent with the general principle here. I also do that kind of intercropping, like radishes between tomatoes, and the weeds just became part of that thinking.

Angela Aragon wrote:I don't know how we got into this idea that we had to have a barren waste land to grow our food in. It makes no sense.


It really has mirrored technological development, which has led to increasing  corporate influence.

Since man first began to farm, he has tilled the soil to plant seeds. Prior to the invention of the plow the tilling was seed hole by seed hole instead of an entire field.
Once the plow came along and horses or mules were used to pull the plow, things started going the way of all bare earth.
Enter the tractor and the tools for decimation were complete.
After the "Dust Bowl" the methods now used by big farm operations were pushed as the way to treat the soil. chemical fertilizers, herbicides and pesticides were already on the market and always new ones were and are being developed.
If you really look at the "new methodology" it is all about mechanization and poisoning to get maximum yield, the fallacy of "feed the world".
Each country needs to be feeding itself, not one country or two or even three, feeding the whole world, it simply will not work.

There are not nearly enough people actually promoting permaculture techniques as yet, to have the needed impact on current methodology, but we are getting there, slowly.

Carrots and many other "slow to germinate" seeds are best planted with faster sprouting vegetables that will come up and provide shade so the soil remains moist for those slow germinating seeds.
This is the "Three Sisters" technique and it works well when understood and incorporated in your planting scheme.


Redhawk

It always amazes me how otherwise sensible people can hyper-focus on yield as the only measure of success in farming. As if yield means anything if it's not cost-effective or sustainable.

Guess it's all in maintaining the balance.  Real life is about applying proper principles to a shifting current situation to "ride the wave" adjusting as needed.  I noticed the article said "a FEW milkweek plants" in a field of corn.  

My wife told me years ago that there are two ways to approach cooking,

1.  collect and follow recipes EXACTLY
2.  figure out why and how cooking works and what the ingrediants are doing, then you can adapt recipes to your current requirements and ingredients.

If you paying even a little attention, the first approach will eventually lead to the second approach, but it happens a lot faster if your always keeping the second approach in mind.  Seems like lots of folks want to restrict themselves to cookbook recipes and not try to dig deeper for the 'why'.

I heard about a man who led a group of thousands who seemed to work together unusually well.  When asked how he governed them the man responded "I teach them correct principals and let them govern themselves."

The wonderful thing (to me) about permaculture is that it teaches general principles that, understood, allow us to adapt to whatever situation we run into.  

Even a poorly cared for, weedy garden is more productive than no garden, so do what you can, but don't not garden because you don't have time to do it "right".  Eventually you'll learn how if you pay attention.

hau Eric,  Greed is the problem, it is the only reason people allow themselves to be fooled into; poisoning themselves, keeping obviously ineffective officials in office, Giving up the freedoms that were hard won in the Revolutionary War, just about anything else you see people do that are more harmful than healing or that lead to true well being of spirit, body and mind.  People are easily fooled when they can be led to believe there is an easy life to be had. When that happens, they are quick to give up liberties for false promises.

Redhawk

Greed is the problem

Bryant, I agree that greed (and maybe pride) are root problems, don't overlook the incredible power of ignorance and stupidity.  Individuals may be smart, but humans in large groups  tend to be stupid, the larger the group, the more stupid.  Hence the need for organizing into smaller groups.

I'd like to add another couple of reasons to befriend weeds in the garden.
We've got a small herd of dairy goats in a dry , high desert climate. We've also got a very weedy but super-productive 1/2 acre of annual veggies. For three months of the year a significant part of the goats' diet consists of weeds from the garden that I cut back( never pull them) and throw over the fence. They will grow back and provide a continual source of nutritious forbes for my hard-working girls. So we are turning our weeds into milk and cheese and cutting our feed costs in the process! Many weeds are dynamic accumulators and I also harvest and dry a lot of them for winter use to add to the feed for a plant-based mineral supplement for the goats.
We've got a plant called sow thistle , an annual that comes up every year. And the goats just love it. I looked it up and it is high in protein( supposedly a very popular staple in NZ and other countries) and increases milk production. I didn't have to plant the seeds and it grows itself. This is just one example of the bounty that happens when we invite nature to co-create with us( as opposed to trying to dominate the garden with our own agenda)

I also have a theory that by leaving some weeds to grow in amongst the crops( but like Eric said, being careful that they don't out- compete the food plants) they help the soil microorganisms and mycorrhyzae to thrive. From what I have read, mycorrhyzae do not form symbiotic relationships with some plants like brassicas and chard. So those beds might not foster as healthy soil as beds with other things growing in them. But if there are weeds growing in the beds with the brassicas....well then maybe they are encouraging the fungal growth in the soil. Plus the fact that we really do not know how plants roots interact with one another. They exchange information and nutrients and all kinds of things that we are only just beginning to understand.

It's all about diversity.  

Sequoia

Last winter I spent a lot of time researching what to plant to discourage unwanted insects.  I planted marigolds and sweet alyssum to control aphids.   There are several beneficial insects that plants attract to control the bad insects that destroy plants.

The article gives the example of milkweed.  While I do not consider milkweed a weed some do, it grows wild in roadways and in pastures.  There are many other weeds that control pests.

Since many people do not want weeds, it is hard to find example of what weeds will attract the beneficial bugs and deter the bugs that are considered pests.

I am always trying to find natural ways to get rid of unwanted bugs.

This year we succeeded by attracted the insects that feed on the bad bugs.

I visited a friend in the Willamette valley late one summer and noticed that there was a 6 inch wide hedge of lambsquarter on each side of his raised bed. when I asked him about it he said it was for frost protection.  The tender greens in the center of the bed were protected from wind and by the mass from frost. Because the lambsquarter had reached maturity it was not even drawing much moisture but shading the soil. Because it was taller than the greens it could even be used to hold up a covering if necessary.  Of course it would reseed itself so the bed would have an early crop and when the center was harvested it could be planted to a succession to be protected by the outer hedge again.

^ and lambsquarter is a delicious green itself!

Many "weeds" are also great for pollinators as well as the parasitic wasps and other beneficial insects.

From earlier this year: via Abundant Design

I've mentioned a study before showing increased yields in Blueberries, and research out of Texas has demonstrated cotton yield increases of 18% with improved pollinator habitat.

But Corn & Soybeans?
Iowa's largest commercial crops corn and soybeans don't rely on pollinators like many other crops.  However, new research by Iowa State's Matt O'Neal suggests growing more bee-friendly habitats could prove to be a worthwhile goal for soybean growers looking to improve yield.  

    Read more http://cornandsoybeandigest.com/soybeans/can-bees-build-soybean-yields

"Three examples of earlier research include:
• A short-term Canadian study found bees’ presence was associated with much higher yields in food-grade soybeans.
• Australian researchers demonstrated yield increases of 10-40% in honey bee-pollinated soybeans, compared to self-pollinated beans.
• In 2005, a Brazilian research project compared soybean seed production with and without honey bee colonies by raising plants in cages, and reported 50% higher yields when bees were present."

I am in an urban setting and have limited space.  Still, I do like to let the "weeds" take over in some sections of the yard - for several reasons:
1. It definitely saves on watering and mulching
2. It makes, what I consider to be, productive use of unused spots - attracting pollinators (with zero effort), trapping carbon, growing wild foods and feeding whatever wildlife still survives in the city.
3. It helps me to understand the quality and nature of the soil, showing me what grows well in which location - where do the wild carrots take hold, for example.
4. It saves me a heck of a lot of time that I would otherwise spend on needless, OCD preening & mowing
5. It creates an interesting juxtaposition to the neighbor's lawn
6. Many times the early weeds provide more food than my early garden plants.

Complications that I have noticed with "letting things go".
1. Certain weedy plants tend to take over and dominate the space - sometimes growing into places where I don't want them before I notice.
2. There are times when I get aphid explosions on some of the "weeds" and it takes a while for the predators to appear.  During that time, a lot of damage can be done when the aphids spread.
3. I have to either separate the weed compost or hot-compost it before applying it to the remainder of my garden, to kill seeds.
4. The weeds can end up thatching over in spots, making them difficult to cultivate later.  Sometimes tree seedlings can hide in the brush until they get tall enough to be difficult to remove.

Lessons I've learned from the weeds
1. Productivity doesn't have to be all for the gardener/farmer.
2. Some weeds are more difficult (and dangerous) to manage than others.  I need to be careful about letting deadly nightshade, knotweed and poison ivy take hold, for instance.
3. Selective weeding, favoring the helpful, edible and less invasive weeds, is more helpful than letting things take their "natural" course.
4. Letting things go indefinitely is not a great option when you intend to cultivate an area later.
5. It is very helpful, if you are going to go this route, to know (and study) your "weeds", otherwise you lose half the benefit and raise the possibility of creating unnecessary challenges.
6. The word "weed" is entirely subjective.

One of my earliest reads on this concept which years later proved a useful review, was a short pdf from "Nature's Way Resources"

https://www.natureswayresources.com/DocsPdfs/shootmessenger.pdf

Even if this list of diagnostics is a woefully incomplete and speculative start, reading a set of "unwanted" "volunteers" for the information they can give regarding soil condition is probably a skill much deeper than making compost, and much less understood.  

Like making assertions more subtle than "taproots help break up compacted soils" and "nitrogen fixer" with regard to this concept, and claiming this assertion as "scientifically" "measured" and not "circumstantial" "anecdote" seems like a wild west.

still, all caps, DON'T SHOOT THE MESSENGER

Eric bee where are you located?

well farmers are catching on. In dry lands farming environments 'no till' is becoming the norm. The stubble and subsequent cover crops will suppress some weeds, but only a few, the balance survive. The whole idea is to keep a crop on the surface and never allow a bare patch of earth appear. Its saves water doing so.

Karl Treen wrote:I am in an urban setting and have limited space.  Still, I do like to let the "weeds" take over in some sections of the yard - for several reasons:

I agree with a lot of what Karl said.  You can't just boil it all down to "weeds" either - there is such a diversity of plants we consider weeds.  Treating them all according to their own growth pattern is a more nuanced approach than either of the oversimplified "No Weeds At All" or "Nothing Is A Weed" approaches.
But I think it's the best way to go, with the least work and higher understanding of what's going on in your garden.  

For example, I'm in S Florida and our most common weed is Bidens alba.  It's an Aster family plant which comes up quick from seed, makes some greens, then makes it's flower and goes to seed.  It gets the name spanish needle because the seed heads are clusters of needles which spread easily.  Before it goes to seed it's a great pollinator plant, edible, medicinal, and keeps the ground moist, shady, etc.  So I want those benefits and I let it grow, but I mow it once I see it's going to seed.  Some seeds still get spread around, but the population is kept under control.  So by managing it that way I get the benefits of having patches of Bidens growing, but minimize the annoyance.  That comes from knowing the plant individually.  There are plenty of other weeds which I wouldn't manage that way, and some I'd remove immediately.

Know your weeds!

I plant field peas and never weed,I even plant tobacco for the peas to clime on,I stir up the fire ants to destroy any pest,best to use what you got

The whole concept of weeds needs review. There are very few plants that I will not tolerate in my land, blackberry because it becomes invasive, kikuyu grass, inkweed, honeysuckle and california thistle all ditto. I take out scotch thistle, tarweed and most of the black nightshade when I see it but many others like taraxicum spp, dock, plantago (both types) chickweed, fat hen, pigweed and others get a lot of tolerance, pretty much all of them get used as cow treats at milking, the dock provides dynamic accumulation, the cows love the leaves and the seeds go into my breakfast muffins.

In general I look at desirable plants and the more that volunteer the better like lettuce, parsnip, kale, tomatoes, spuds etc, compost volunteers which is anything that wuld be tolerable but is in the way of something I need more, and charcoal feedstock for anything whose roots, leaves or seeds I want out permanently. Weeds, however, don't have many of them.

Thank you for sharing! I would love to convince some of these farmers. When my father or father-in-law talk about weeds I will say 'a $20 rose is also a weed in your precious $7 a bushel corn field.'

When weeding in a bed with young plants to clear out the competition, I've come to leave in all the Fabacaea, mostly clover, which appears. As everyone probably knows, they fix nitrogen, so they are actually helping soil fertility, plus they attract pollinators.

Even the weeds I remove or chop up are useful, as their remains becomes compost, either in place in the growing bed, or in the compost pile.

I define weeds as any plant that is in the wrong place. therefore any wild plant that helps my garden is not a weed.
I have a lot of open land, more than five acres, that I do not garden, so the weeds can have it, my one little acre is for me & I will grow what I need & want there.
It seem fair to me.

We have been experimenting with mowing weeds in pathways with a string trimmer. It seems to work well but I would like to use the metallic string so there would be less plastic residue from the string. We also bought a 24 inch flail mower which we will use in the wider areas. I try to mow before there is too much seed set, but I suppose a little seed is okay for next years free cover crop.

However, I agree that some weeds are not negotiable.

We rake or pluck out quackgrass roots whenever we find it growing. It doesn't seem to be very picky about where it grows.

We experimented with letting galinsoga run almost wild in a previous garden, and we are now trying to keep that totally out of our new garden. Galinsoga is really hard to "work with" in my experience. Because it pops up so secretively and sets seed so quickly, it can almost choke out crop plants. Even knowing we can harvest it for food was not a big help, although it is a good salad plant and spinach substitute.

In our new garden, we have crabgrass, which we are learning about. It doesn't appear to be a bad weed at this point; I'm told it's just signalling anaerobic tight soil, which we are trying to correct with crabgrass's help. However, if it turns out to be a villain, I will try to mow it a little harder to keep it from setting seed.

As some others mentioned, plants such as plantain, dock, dandelion, clover, fleabane, aster, evening primrose, and others are not bad weeds if they aren't right next to a crop plant. I like the diversity they provide and the beneficial insects they harbour.

I look forward to further discussion on this topic, and especially pictures of what others are doing. I will try to get pictures this summer.

A weed is an unwanted plant: In a lawn a rose is a weed, in a rose bed grass is a weed.
If you want the plant it is not a weed. Simple.

duane hennon wrote:
I know this is crazy
but Cornell University (probably with some grant)
has come out and said that weeds may be good
who knew?

http://www.futurity.org/weeds-pest-management-1295912-2/?utm_source=feedly&utm_medium=webfeeds

Why farmers may want to keep, not kill, weeds

“The benefits of weeds have been neglected. They’re often seen as undesirable, unwanted. We’re now beginning to quantify their benefits.”

My horticulture teacher had a definition for weeds: " A weed is a plant growing in a place you don't want it to."  So even flowers and veggies could be termed 'weeds' under  that definition, if a corn plant was in the middle of  a flower bed, or a petunia was in a onion patch, since they are not supposed to be there by some standards, they could be considered weeds.

Personally, if it grows, it has a reason in nature.  We can take  things out of areas, but  try to  do it so that you can replant it somewhere else more suitable

To me, any pest or weed is both information, and a potentially valuable resource. So many weeds indicate different nuanced soil conditions, like pH, organic matter levels, aerobic/anaerobic biology, compaction, looseness and especially mineral availability. They are often edible to me, and always edible to something, at very least the soil or the compost pile. Pretty much all weeds accumulate one or another mineral nutrient. Weeds are often symbiotic with my preferred plants. If they are actually a problem, I generally chop and drop them. This delivers the minerals that that plant specializes in back to the soil.

I consider pests and diseases either symptoms of weak/stressed plants, or of predator deficiency. Pests should be turned into a resource, by some kind of conversion factor. If I have a pest problem that looks impossible to beat, I look to the soil to tell me why the plants are practically begging to be removed. I also ask myself what keeps this pest in check in it’s own native range, and see if I can turn the answer into a resource-generating solution.