Wednesday, April 15, 2009

Myths and Legends - Raised Beds vs. Traditional Beds

I will make it no secret that I am a huge proponent of no-till gardening and farming practices. I've read plenty of research on the subject and having studied microbiology in college protecting microbes just plain makes sense to me. When I see a gardener out with a roto-tiller grinding up their garden I cringe, but I certainly don't stop try to force them to garden with my beliefs. The truth of the matter is there is no universal right way to garden. Each gardener has their own reasons and motivations and must find their own path. Still it doesn't mean we can't try and sway people to our beliefs!

I read a post on Garden Rant at lunch today discussing a post by a Uk Blogger at Simon's Allotment. He believes that the benefits of no-till raised beds are a myth. While I certainly don't believe raised beds are the only way to go. I do believe that they come with a wide array of benefits. Let's take a look at some of the thoughts Simon puts forth to support his point of view that raised beds aren't worth the trouble and I'll respond with my thoughts in kind.

To start with, this has been the orthodoxy for many years because, I presume, our ancestors spent hundreds of years figuring it out. I think it's worth paying them some heed. Unlike us urban dwellers they spent their whole lives on the land so it's not unreasonable to think that they knew a thing or two about what they were doing. -Simon

There are innumerable things we can learn from our ancestors and elders, but taking their practices as truth is foolhardy. Just because we've always done it that way doesn't mean its the only way or the necessarily the right way. I both ski and snowboard and would hate to have missed out on snowboarding because skiing had worked just fine for centuries.

Now imagine a forest on a hundred acres and all the diversity it contains. But in a forest of only ten or even fifty acres there will likely be less diversity. Now going back to our life in the soil I would like to postulate that THE MORE SPACE IT HAS TO MOVE AROUND IN THE MORE LIFE AND DIVERSITY THERE IS LIKELY TO BE. -Simon

Lets take this analogy to its logical conclusion. While more space to grow is certainly preferable tilling the soil each spring is like taking the hundred acre forest and sending a tornado methodically through all of it each year. If we have a ten acre forest that is left alone the plants and animals there will almost certainly be more balanced and better off. We must remember that just as we have a band of conditions we can survive in, so do soil microorganisms. Moving soil from a foot down to the top of the garden might not seem like a big deal to you, but it can be the equivalent of taking a human and dumping them on mars.

At the same time plants can still thrive in a ravaged microbe-poor environment giving the right amendments. Just because a practice makes life suck for microbes doesn't mean it won't work for growing plants. My personal belief is rich and stable ecosystems are less prone to disease and will produce higher outputs. So long as they are combined with practices such as crop-rotation.

It is true that no-till practices can lead to more pest bugs, but the knock on of that is more predators. When I walk into my garden I can spot dozens of predators from wasps, to spiders, to lady bugs, to snakes and birds. The important element is creating a stable ecosystem. An aphid outbreak in a normally sterile garden can be devastating because the predators aren't there. In a balanced garden there will be aphids and other pests but they will be kept in check by the predators that make your garden their home. This of course is not raised bed exclusive.

I've worked in gardens with raised beds and unless they are waist high then it's extremely uncomfortable trying to work on them without walking on them, or at least putting your boot on them from time to time. -Simon

I'm 6'5" tall with a wingspan of 6'7" from finger tip to finger tip. It is an unfair advantage that I can reach into the middle of a 5 foot wide raised bed without effort. This cycles back to each gardener being unique and needing to find the way that works best for them.

Unfortunatly, leaving compost on top of the soil means you lose a lot of its goodness through oxidisation. (I too use compost as a mulch once plants are growing away nicely, if I can spare it, but this is in addition to, not a substitute for, incorparating it into the soil at the start of the season). - Simon

This goes again to my point of a stable soil ecology taking care of itself. While it may look like the compost is just sitting there, the truth of the matter is there are plenty of creatures in the soil that drag that material deep into the earth. One that you may be familiar with is the noble worm. I hear that worm poop makes plants happy, but it could be another one of those myths.

By then the top of the soil has likely settled and dried out and isn't going to be compacted because I walk backwards with my dutch hoe loosening it up. And all that life is still going on its merry way beneath my feet. - Simon

This statement reads as ignorance is bliss to me. It is the same false sense of security that keeps tillers ignorant of tiller compaction. Just because the top couple inches are light and fluffy doesn't mean the same is happening a foot down. You're also killing untold millions of soil microbes by agitating the soil with your dutch hoe. So first you're crushing the spaces they live in and then throwing them about with a hoe. Soil microbes are fragile and this does kill them. They want to help you grow plants, really they do! Just let them live.

Raising the soil a foot above the water table inevetably means lots of watering, especially around the edges near the boards where the soil will quickly dry out. - Simon

I live next to a swamp. When it rains hard my garden floods and my plants die because they cannot breath. Having the raised beds allows the beds to drain before the plants die and the paths between the beds flood instead of the beds themselves. While I appreciate that in ground gardening works for Simon, I would lose whole crops to storms. I was really lucky last year that each time my garden flooded the rain stopped and the sun came out. It sapped the non-raised bed plants each time and a another day of rain would have done them in for sure. Our raised beds plants loved the storms that weakened the in ground beds. This is why they're all being raised this year.

You'll have to make paths between your beds which means slabs - a lot of slabs - or imported bark with dozens of metres of weed control fabric underneath it, or hours with the strimmer. Again, I'm not a scientist but it would be interesting if someone were to do a study of the time/reward ratio of all this compared to two or three days digging once a year. - Simon

A little cut here, a little cut there and all the cardboard we have from any number of resources become a perfect weed blocker for the pathways. They also decompose nicely on their own over the course of the year. It is also important to note that weeds become less and less of a problem over the years in a no-till garden. Agitating the soil brings buried seeds to the surface and gives them a chance to grow. Good weeding along with no-till practices in raised beds eventually tamps out all the viable weed seeds save those blown in on the wind that can make it through the living mulch.

For me raised bed gardening just seems like an unnecessary complication. What's wrong with "There's the ground - go work it"? But that would be absurd. Wouldn't it? - Simon

I think it would be anything but absurd. It is a practice that has worked for year and will continue to work for gardeners across the globe. The most important element is that you don't see the value and with that in mind I see no reason for you to go through the trouble. Still I also don't see those who go through the trouble of making raised beds as being absurd either.

The final issue to discuss is cost. Setting up a raised bed is going to cost more in materials than just digging a bed in the earth. If you buy a kit instead of doing it all yourself it can cost even more. While that cost is amatorized over years the up front cost might dissuade new gardeners and that would be a shame.

I'd like to thank Simon for helping me to hone in on what my beliefs are, and I wish him and any other 'absurd' gardeners the best of success with their gardens and their techniques.


Simon said...

Wow thanks for putting so much thought into your reply. I like the tornado analogy! Whilst I'd not use raised beds in my situation I am now thinking of doing a no-till experiment next year on a small part of my plot to compare results using the same crop with the two methods.

Cheers and thanks again, Simon.

Michelle said...

Hi Simon! Thanks for stopping by our blog! I look forward to reading about your no-till experiment. Cheers!

C4 said...

Hi Simon!

Thanks for taking the time to come visit and read my take on it all.

We have a small 8x4 traditional bed that hasn't been converted to raised yet that will make a perfect testbed for a comparison between its production and production from an equal raised area. With identical potato plants in both beds we should have a somewhat scientific experiment. This could be fun:)

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