Is woodchip good or bad for a vegetable garden bed?

Do you think woodchip is bad to use in your vegetable garden?

  • Yes

    Votes: 0 0.0%
  • No

    Votes: 2 100.0%

  • Total voters
    2

Mark

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Up until now, I have never used woodchip as mulch in my vegetable garden beds because I have always heard woodchip can deplete the soil of nutrients (particularly nitrogen) and that's not a good thing when growing a food garden.

However, something deep down in my instinctive gut kept nagging away at me over the years urging me to use woodchip in my patch even just as a trial... And, lately (the past few years) I had been reading and seeing videos about others who do use woodchip in their food gardens with only positive results!

So I decided to finally give it a go in my raised garden beds and see what results I get. In truth, I have been mulching around my fruit trees with woodchip from when I first started our orchard and all the fruit trees seem to have done well - I've certainly seen nothing negative.

We have a lot of established trees on our property and they tend to drop a lot of debris, plus the odd fallen tree or big branch, not to mention the pruning I do, and all this gets chipped into mulch once or twice a year. It always made sense to me to use it as a free mulch around the ornamental garden and orchard, therefore, I'm thinking why not in the vegetable garden!?

What do you guys think - use the attached poll to cast your vote and post your thoughts why you believe woodchip is good or not in the vegetable garden?

Here's a video I knocked up on preparing one of our raised beds with woodchip.
 

Steve

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I can't remember where i saw it (probably on SSC) but there was someone who use bulk wood chips on their whole property and added mushroom spores to break it down quicker. It was an awesome idea and their soil looked pretty healthy to me.
I think plants/trees etc are just an extension of the soil so they should compliment just about any crop nicely. It will slowly break down and in the mean time provide all the good things that mulch does (cool the soil, retain moisture etc). There's probably some exceptions with specific species that don't mix with certain crops but lets not complicate the issue, stick to the KISS principal.
Play on I say.....and can't wait to see the results. :twothumbsup:
 

Mark

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The use of mushroom spores is a good idea.

When I was moving the mulch from its heap I could already see the white "roots" like veins forming through it from fungi I suppose slowly breaking the mulch down.

Yes I tend to agree... it makes sense woodchip being plant material and organic should give more than it receives. If (for argument sake) the process of breaking down the chip removes some nitrogen from the soil then it's just a simple matter of adding a little extra nitrogen fertiliser - too easy ;)
 

GlennoFromKenno

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Surely the rate of nitrogen depletion would be too slow to affect most annual crops? Might be an issue for longer term perennial beds, but a bit of chicken poo/other nitrogen rich fertiliser should fix up the balance no? Looking forward to hearing more about how your experiment goes mate.
 

Mark

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Yes that's a good point and I'd think the rate of nitrogen usage by the woodchip would have to be pretty slow (if at all) I just don't know for certain.

Yesterday I threw 3 wheelbarrows of woodchip in our quail pen for them to work over and turn into a fertiliser mulch hopefully in about 3 months.

Putting it through the quail pen first before the garden should work well but I expect you could get a similar result by adding some organic chicken pellet fertiliser (like Rooster Booster) to the woodchip in the garden bed as a way to correct the loss of nitrogen.

Welcome to SSC @GlennoFromKenno cheers mate :cheers:
 

Mark

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Hahaha... Yes fantastic indeed... many of them are rather cringeworthy but I get a lot of fun out of making youtube videos - I'm improving slowly :D

Thanks
 

desman

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I know this is a super old thread, but the nerd in me can't help but add as I've seen quite a few YouTube vids or blogs in other places etc about wood chip sucking nitrogen out of soil. Of course SSM channel suggests it's not going to do that. Which is true. I have a hydrochemical background and couldn't resist adding to this topic as once you understand the science behind it the answer is obvious. Denitrification is really only going to happen when there is low or no oxygen. Basically the bacteria use oxygen, and when it's not available they steal it from other molecules, like CO2, SO4 (sulphate), and NO3. It takes more energy to get it from molecules so it will only happen when oxygen is scarce. The process is generally called reduction. Reduced CO2 = CH4 (methane), Reduced SO4 = H2S (rotten egg gas), Reduced NO3 = N2 gas, or denitrification. If your soil is denitrifying then it's probably water logged and anoxic and you have likely have bigger problems than whether to add wood chip or not.
 

Grandmother Goose

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I know this is a super old thread, but the nerd in me can't help but add as I've seen quite a few YouTube vids or blogs in other places etc about wood chip sucking nitrogen out of soil. Of course SSM channel suggests it's not going to do that. Which is true. I have a hydrochemical background and couldn't resist adding to this topic as once you understand the science behind it the answer is obvious. Denitrification is really only going to happen when there is low or no oxygen. Basically the bacteria use oxygen, and when it's not available they steal it from other molecules, like CO2, SO4 (sulphate), and NO3. It takes more energy to get it from molecules so it will only happen when oxygen is scarce. The process is generally called reduction. Reduced CO2 = CH4 (methane), Reduced SO4 = H2S (rotten egg gas), Reduced NO3 = N2 gas, or denitrification. If your soil is denitrifying then it's probably water logged and anoxic and you have likely have bigger problems than whether to add wood chip or not.
Science is such a wonderful thing. I don't think this forum nor anyone using it is worried about people doing a bit of thread necromancy (raising old posts from the grave) here. I'm glad you did or I wouldn't have ever found this one. I've heard a lot about certain types of bark chip, particularly pine, raising acidity levels in the soil, but even that I can't see as being a problem given that most fruits and many veg either love or even if they don't love they at least don't mind a bit of acidity, and those that really don't can be easily sated by adding a little bit of wood ash (or a commercial base product) to the soil to bring the pH back up again. Which has always made me wonder if the stories about bark chip being no good for gardens was started by someone that wanted everyone to buy their other type of mulch product instead, because after all, most of the time when these types of completely unfounded stories go around one can usually figure out where they came from by following the money, because someone somewhere benefits from people believing such things.
 

KathrynJN

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One thing I've heard recently is that leaving the bark chip mulch on top is ok, but it's the digging it in that depletes the soil.
 

desman

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Science is such a wonderful thing. I don't think this forum nor anyone using it is worried about people doing a bit of thread necromancy (raising old posts from the grave) here. I'm glad you did or I wouldn't have ever found this one. I've heard a lot about certain types of bark chip, particularly pine, raising acidity levels in the soil, but even that I can't see as being a problem given that most fruits and many veg either love or even if they don't love they at least don't mind a bit of acidity, and those that really don't can be easily sated by adding a little bit of wood ash (or a commercial base product) to the soil to bring the pH back up again. Which has always made me wonder if the stories about bark chip being no good for gardens was started by someone that wanted everyone to buy their other type of mulch product instead, because after all, most of the time when these types of completely unfounded stories go around one can usually figure out where they came from by following the money, because someone somewhere benefits from people believing such things.
I find even amongst scientist people attach to things innocently and then they become gospel. Belief is a powerful thing. Maybe some context was missing as this topic was discussed by others in the past. There’s a lot of incorrect info in gardening world on this. I always like to know they why behind things, but that’s just me.
 

desman

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One thing I've heard recently is that leaving the bark chip mulch on top is ok, but it's the digging it in that depletes the soil.
I do think that rumour is a bit of a furphy. The nitrogen cycle is pretty complex, but basically the only way nitrogen will leave the soil is if those nitrogen sources are converted to gases such as N2 in the denitrification process, which generally is only significant in low oxygen environments. In Great Barrier Reef catchments where excess nitrogen is polluting the reef scientists and farmers are trialling burying wood chip to remove excess nitrogen from the soil. These ‘bio reactors’ exploit denitrification but they only work if the mulch is buried so there is no oxygen.
In typical soils adding mulch whether to the top or dug in won’t deplete the soil of N, as in exacerbate a denitrifying scenario where lots of nitrogen is lost to the atmosphere. Think Hugel mounds, which are buried logs etc: if wood chips depleted the soil if nitrogen then Hugel mounds would do the same. Also if wood chips depleted soils of nitrogen, compost would be low in nitrogen, which is often not the case.
Fresh mulch might create a scenario where microbes use a lot of the nitrogen in the soil, making it less available to plants, but this is temporary and the nitrogen will become available to plants again once the fresh mulch has broken down somewhat.
Anyways, I’m only aware of this stuff because of my profession touches on hydrochemistry and I thought others might like to know some info. Back home in the garden, I’m a self confessed amateur and and often grower if pretty crappy veggies. I think I have a lot to learn, especially to be successfully self sufficient in the subtropics.
 

JP 1983

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Throw some blood and bone on top of the woodchip (don't water it in) and you'll get your answer for why it allegedly depletes nitrogen.

I found this out quite by accident only a month ago. I was crumbling b & b on my potted citrus which has a woodchip mulch, getting it ready for spring growth and got distracted by wifey and forgot about it. Anyway I came back 2 days later to water the lemon, and the woodchip where I had sprinkled the blood and bone was caked in white mould. I'd given them a bonanza of nitrogen and they were going wild (and so were the damn fungus flies... ugh!). Note that these were surface level moulds and there was no shortage of oxygen for them.

So I don't think it's necessarily the case that woodchip in and of itself depletes nitrogen, but the fungi, moulds and bacterium that like to live on both woodchip AND nitrogen certainly do.
 

Alpenrose

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We live in high country. Pine and fir trees are the dominant source of wood chips here. Many people use wood chips from those trees on top of the beds, with no negative impact. What you don't want to do is leave the needles laying around on top.
 
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