Monday, April 9, 2012

to till or not to till

she prefers getting a ride on the trike over riding her bike with the new training wheels

That's the question.  Now that it's really spring, and even though it's supposed to freeze tonight, most if not all gardeners around here have either begun digging up their gardens or are thinking about doing so really soon.

Whether or not to till has become far more controversial than I ever thought it would be.  Tilling, generally meaning turning over the soil with a rototiller or other machine, that is. 
I subscribe to the comgar listserv, sponsored by Gardening Matters (they're on the sidebar, a non-profit and a good source of community garden information by the way) and have been following a thread on the merits or demerits of tilling a garden.

On the merit side is the fact that it's quick, it de-compacts a new garden which is starting with compacted or otherwise difficult to dig soil, it kills off weeds if done repeatedly, and causes a 'flush' of nitrogen by way of suddenly exposing the soil organisms to lots of oxygen.  It also leaves the top of the soil looking nice and neat.

On the demerit side is the inconvenient fact that repeated tilling breaks down the structure of the soil and eventually leads to new compaction, due to that lack of structure, or tilth, as well as the weight of the machine.  The flush of nitrogen turns into a nitrogen deficit, and some say that there will be more weeds as a result of tilling, as this exposes buried seeds to light. 

So do I till or not?

Some of my earliest memories are of watching my dad till our backyard garden.  We had a large backyard when we lived for a while in a northern suburb of Minneapolis, and I remember how excited he was to get his new red  rototiller.  It was probably 1975 or 76, and there weren't many people around with their own tiller.  There weren't really even that many people in our neighborhood with vegetable gardens.

 It was a massive thing that sat in a corner in the garage for 363 or 364 days a year.  The neighbor kids were fascinated by it and came over to look at it.  One kid fell on it and cut his head, and had to go to the hospital for stitches.  The tiller was interesting, and a little bit scary.

The day or two that dad used it though were fun ones.  It was loud and smelled like gas and he walked it back and forth across the garden a few times.  Watching it rip up the sod or last year's brown plant leftovers was fun in the same way that watching construction equipment was fun, except that the construction was taking place in our yard.

So when I started my garden here in 2006, of course I figured I needed to at least borrow a tiller.  So I did.  My sister had bought a used one years before so I borrowed it and proceeded to tear up a portion of our new backyard, probably to the neighbors' horror- though nobody said anything at the time.

What I found out, was that tilling wasn't easy at all.  It was a lot of work, and not really fun work at all when I'm the one behind the tiller, trying to keep in going in a straight line and breathing gas fumes the whole time.  And they're loud.  Louder than a gas lawnmower, and potentially more dangerous.

The tiller stopped working part-way through, and I finished digging up the garden with a shovel, which was quieter and really not a whole lot more work.  I struggled to load the tiller back onto the truck I owned at the time and wondered why I had bothered.

turnips and spinach popping up in the (sort of) tilled soil
That same spring, I was surprised to find morels growing in our lawn, cut down by our gas lawnmower and scattered over the lawn like torn kleenex.

I thought that there must be a better way.  I had heard of no-till gardening, and decided that the next year I would try it- to avoid the hassle of tilling, and to hopefully preserve the mycelium in the soil that were sending up the morels.

scilla and fern-leaf bleeding heart blooming near the rain garden
That year, and the year after, I not only didn't till, I didn't even spade the soil over to aerate it, choosing only to cut off last year's top-growth from the veggies with a garden hoe and leave the dead roots of the plants in the soil to stabilize it.   In theory, the roots would decompose and feed the new plants.  Mulching the top of the soil would hold in the moisture and keep the weed growth down.

However, it didn't quite work out that way.  The morels went away, despite the lack of tilling, and the weeds were abundant.  The tilth of the soil may have been good, but it didn't do the plants many favors.  Gita dismissively called it "Tharu gardening" after the no-till methods used by the native Tharu people, which are less effective, at least in the short term, than the 'green revolution' methods used by the more recent settlers in the Inner Terai region of Nepal.  And she had a point.  Our no-till garden of years two and three was nowhere near as productive as our tilled garden the first year.

After the second year of experimenting with no-till gardening with lackluster results, I decided to go half-way back and turn over the soil, but only with a shovel, and incorporate as much organic matter as I could in the process.  I wasn't too thorough in my shoveling, so some soil was left undisturbed. I also made sure that lots of leaves and old plant matter were dug back into the soil, then raked off the rough stuff remaining on top to make a smooth surface for planting.

And it worked!  The garden had the vigor that it had had the first year, and fewer weeds, though I continued to mulch as well as I could.

I've stuck to that method now for the last few years, and it continues to work well.  And I enjoy the process.  After years of working organic matter into the soil with a spade, the soil is black and rich.  I don't have to wrestle with a loud smelly machine, and the total time I spent this year preparing our 400 square foot veggie garden bed came to about an hour and a half of shoveling and raking.  Not bad by my way of figuring.

his tree is a autumn brilliance serviceberry
I've been heading up a group this year working to start another community garden in our neighborhood.  Our current community garden is slated to be used as a construction yard by the city of St. Paul for the 2013 and possibly 2014 growing seasons.  So we've just received approval from our district council to go ahead and start gardening this year on some public land near the interstate highway.

And of course, one of the most controversial questions is whether we will till, or not till.

Right now (and this may be a reasonable way to start) lasagna gardening is the way many of the gardeners are leaning.

I have no experience with it, but apparently it's a method involving laying cardboard or multiple layers of paper over the existing grass
it flowers just after his sister's tree and bears blue berries in june
or other vegetation, then piling layers of leaves and/or other compostable matter on top, in the manner of a lasagna hot dish.

It's an interesting idea, and a great way to use a lot of materials that might otherwise go to waste.  In theory, with the cardboard keeping the soil moist, the worms go into overdrive and begin tilling the soil with no effort required by the gardeners.

I don't know if it will work out
budding lilacs indicate a soil temperature around 55 degrees
that way, but for a group just getting started, and with little money for tiller rental, it may be an ideal solution.  I hope that it works better than my early not-so-successful attempts at no-till gardening.

The site has sandy, gravelly urban soil, full of the remains of a building and possibly a parking lot, having been bulldozed in the 1950s or 60s when the interstate was pushed through the middle of the city.  It's a tough site to test this sort of thing on.  If it works, I suppose it'll make a believer out of me.

Until then, I'll turn over my own plot every year with a sharp shovel.

---------and by the way---------

If you happen to live in Saint Paul or Minneapolis and have bags of leaves that you raked last fall or this spring still sitting behind your garage, please consider dropping them off on Saturday April 14th at the new Merriam Station Community Garden at the corner of Prior and Gilbert streets, just north of I-94.  We'll be using the leaves as a sheet mulch this year and compost the next.  We have a massive area of mowed grass to convert to garden plots, so please grace us with your bags of leaves yearning to become sheet mulch.

Bags of leaves will be accepted from 10AM to 2PM and I will personally be there on site until about 11:30.  Please don't drop bags of leaves off afterward, as the city is a bit particular about that sort of thing, so we have to be careful to make the whole thing look nice until we get around to using all of the leaves.

If you'd like to learn more, visit the Union Park District Council website and click on "Merriam Station Community Garden" on the left sidebar.

Thank you in advance!


  1. Argh...

    What we have here is a failure of education...

    Switching from industrial agriculture ALWAYS gives poorer results, FOR 3 TO 5 YEARS. It takes that long for the soil to get healthy again.

    Your experience with no-till is thus meaningless.

    Tilling is a lot like heroin. You feel great the first time. But once you're hooked, the results gradually get worse and you have to make up for it with more and more fertilizer.

    What you're doing is more like opium. You're not doing as much damage, so you can get by on the organic matter you're adding.

    Please Please Please don't judge the results of the no-till gardening for 5 years.

  2. Uggh. With a small urban garden, who has 5 years to wait for a productive gardening year?

    I use a Golden Garden Claw by Weasel to break the soil up a bit. I wouldn't really call it tilling. More aerating and loosening. Luckily we don't have too much of a compaction problem because the worms go berserk come spring and aerate the soil like crazy. Plus many of the beds are already demolished from last season--digging up carrots, parsnips, leeks, onions, garlic, beets, potatoes.....which can be really messy (not to mention impossible to dig up while not disturbing the soil).

    I don't think it's a big deal to do some mild tilling on a small urban farm. My soil has been great just adding in a bit of compost to the top few inches of soil every year and mulching. Minimal weeds and awesome production with a little help from some fish emulsion and of course no "chemical" fertilizers.

    1. Nick, I love my Garden Claw too. I do use it a fair amount, in small areas.

      I am definitely not advocating never disturbing the soil. I chose the heroin/opium analogy very carefully. Like morphine for patients in major pain, there are times when tilling is appropriate. For example I'm planning on completely digging out several beds for hugelkulture. Also, on this spectrum, pulling up root crops is more like eating poppy seeds, you can do it all the time. What's important is not killing off the web of life in the soil and not burning up the organic matter faster than it is being added.

      From your results it sounds like you have a darn good system going. The fact that you have a good worm population is a great indicator, along with the minimal weeds and awesome production.

      From the extreme abuse received by the site mentioned in the blog, I think 5 years is entirely reasonable, assuming a low budget. I actually have an area of my property that was destroyed last summer when they put a water line through. But when I am starting with undamaged soil, I find a simple sheet mulch over one season gives pretty good results.

      If time is more important than money, the best results I've found come from just buying bags and building an excellent mix on top of the soil.

    2. Hugelkulture sounds very interesting. I had not heard about that before. Now I have another obsession to think about. The C:N ratio in the short-term might worry me a bit, but sounds like it's been working for centuries, so who am I to judge? I always think it's funny that many people don't know that most non-decomposed/ing organic material actually takes up nitrogen out of the soil before any nitrogen is released in a plant usable form. But as long as there is enough nitrogen present, I bet Hugelkulture creates an amazing soil.

  3. RE: the lasagna gardening method - I subscribed to Organic Gardening magazine a few years back, and think I saved their article on doing something like that - haven't tried it yet, though.

    1. Found the article:

  4. Rather than a sharp spade to cut through the worms, I use a garden fork, which may not protect that many more worms, but it makes me feel better. That, and I think the fork does a better job of breaking up compaction. I'm not forking up two of the tomato beds this year though, as a test, just pouring a little compost on the old stems. Not sure that I could go with the no-till method, as I prefer not to mulch, except around the edges - the neighbor mulches, and he has a considerable slug problem. I like the idea of hugelkulture if not the name (it sounds like some sterile school of nuvo-mod architecture.) Last year I used a riff on a Jeavons method, pulling out the top twelve inches of soil, pouring in a few inches of carbon matter, and forking up another twelve inches. I now have nearly two feet of loose tilth. Hard work, especially if the winter store was exhausted and you were starving, but good for 2-3 years.

  5. Jeff - Just like any project (building a fence, sweating copper pipes, or building rain barrels), gardening and garden installation has many tools that can be used, and many of them for specific tasks. I have put the majority of my beds in using the lasagna method. I love it and have had great results. One draw back though is having enough organic matter to work with - grass clippings, leaves, straw, cardboard, rotted manure and compost. With the size of most community gardens you will need a lot of materials to do it successfully, so hopefully you have a good, core group of gardeners to help out and scrounge up the materials. Since the garden is being sanctioned by the city of St. Paul, talk to the person in charge of the city compost sites to see if they can help. I commend you for your efforts of starting a community garden. My wife and I did that last year here in WSP and this is what we got ... .. A whole lot of nothing, and betrayal on the part of the city council and citizens. I wonder what kind of world some of these people think we live in - well the future will show them that community gardens will be essential to help feed ourselves when gas is eight dollars a gallon. I hope you have better luck - Peace & Cheers - Andy

  6. Wow- what a response! I opened a can of worms, no?

    John- I agree with Nick. 5 years is too long to wait for results in my back yard. I garden intensively, taking a lot out of the soil, but I also put a lot back in. Never chemical fertilizers, but I do work in a lot of leaves, grass, dead plants and compost. Really, very little organic matter escapes my yard. Most of it ends up in the veggie plot either as compost, raw organic matter or wood ash. Even the dead squirrels end up in the raspberry or blueberry patch. As there's no consensus on tilling or not tilling (I'd get an equally vehement response from a county extension agent on the other side of the spectrum, I think) so I like trying both approaches. And this is what I've settled on, a low-till method rather than a pro-till or no-till.

    And I think what is appropriate varies with the site and the soil. I have a small,level site with sandy loam and high organic matter. The soil is crumbly and pretty resistant to compaction, so it can take a lot. If I had clay, or was on a hillside, or had to work 100 acres, the appropriate method of working the soil would be different.

    Amy- I may have to look up that article on lasagna gardening. An email conversation I had with one of the community gardeners today makes it look like we may be going the sheet mulch route- at least for most of the garden. I'm looking forward to seeing how it works!

    Also-Nick and John- I'm going to look up the Garden claw. If it's similar to a broadfork, then it may be something that we may be purchasing for the community garden.

    William- I think about the worms when I dig- but I have a shovel that is one of my longest-lasting possessions. I've had it for over 15 years now, and it fits my hands like nothing else. I've worn the handle smooth, and the blade isn't sharp from filing, it's sharp from heavy use. The end is even notched from my trying to dig some rocks out of a garden years ago, but it still works better than the new-ish shovel I inherited a few years ago. A sturdy and well-used tool is a beautiful thing, and I just like using it. If it ever breaks, I probably will cry- and then I'll try using a fork to work the garden.

    Andy- We are having a compost drop-off day for the neighborhood this Saturday (that reminds me that I should post a link for it here). We're hoping to get people to drop off their bags of leaves for the start of a sheet-mulch at the community garden site. Depending on how many people show up, we may have enough organic matter overnight. Also- I saw the article after someone posted it on comgar. I can't believe people seriously still believe that community gardens attract rats. Rabbits, yes, but other rodents, no, at least not in my experience. Don't give up on it. There's a lot of support for community gardens growing, and the picture may be different next year.


  7. I grew up in Nepal in a farming family. My dad was a farmer, farm was main source of income for family of 8. Not tilting was not a choice. But he skipped planting part of land every year to make sure soil is good. Most of the time my dad harvested very well: rice, corn, mustard, all sort of vegetables. geetz.

  8. It was definitely wise on your part to opt for rental equipment services instead of buying those which you'll just need for certain occasions.