How to Use Wood Chips & Shredded Wood for Compost, Mulch & Potting Mix | No Dig Gardening Tips

Wood is a fantastic source of organic matter for use in the garden to improve soil. And how to use it? Because if you put on fresh wood, which some people do actually, I've never succeeded very well with it. You get a lot of wood lice, tingy winkles, and they eat a lot of small leaves and the decomposing wood on the surface is not actually, if you put it on fresh, it's not adding a lot of goodness to soil very quickly. It's a very long-term project. You know, if you wanted to beef up your soil over a period of years and you didn't need to use it immediately, that's an option. What I'm looking at here is how to treat wood, cut it, and then look after it in a way that it turns into compost maybe quite quickly. And there's a range of options because wood chip, as it's most commonly referred to, is now pretty available because it used to be burnt often in bonfires. People don't do that anymore. It's brilliant. So the wood is available as organic matter. Also, we've got motors now that can chop it up and shredders. And I want to show you here a range of options, starting with some wood here, which we've put through this sieve. So that's a throw-through, standalone 12-millimeter sieve. And I'm just chucking it down here so you can see it really, but that's already been through the sieve. So this is wood. And look how beautifully soft and crumbly it is. And it's roughly three years old. It's from wood chip that started as the big chip behind me there. Adam, last week, put it through the sieve. We've actually sieved it three times already. We sieve it every year and then put it back and it decomposes again. And then you can sieve out the bits that have decomposed the most, which is what that is, basically. And then we put this through another sieve, which is a smaller one, four-millimeter. This is 12-millimeter, half-inch. Four millimeters, about a sixth of an inch. And that separates out the woody bits that, even here, some of these more woody bits of wood, if you've gone through the 12-mil, you can see that's a long one, but it goes through lengthways. So that's not so good as surface mulch if there's too much of it, because that's when you do get buildup of mainly the wood lice. But also, it's not adding anything to the soil for quite a few years. And generally, with vegetable growing, you want to get some goodness into the soil, not physically, but taken in by soil life. When this is finer, it makes a fantastic surface mulch. And actually, although it's only wood, it's amazingly nutritious. I've just tried a trial, just to see. I sowed spinach in the sieved compost of this two weeks ago, and it's come up really, really healthily. It's got a very good structure, and that's very good for little roots in seedling module-trace cells. And there's no compaction or drainage. The drainage is really good. There's no water logging. So the spinach are looking really strong. We're going to plant them today, two-week-old spinach are going in the ground in wood. I did add a little bit of seaweed and a little bit of very fine rock dust, which is kind of trace elements, more for longer-term health and well-being. So that came from this, and this is what is left after putting it through the 12-millimeter sieve. Pretty unpromising, large bits of wood. Some of this is even four years old, actually. It's a bit of a mixture of, it's wood that we've sieved out of heaps over the last three years, but on average, about three years old. And some of these bits are really too big, you know, bits like that, bits of wood like that, hardwood. This might be poplar. They're never really going to break down within the next five years to any significant degree, but little bits do decompose off them, and that's what can give you that fine wood in the end. And checking the temperature of the heap is one way to see what's going on. So it's 21, 22 degrees there. The ambient temperature this morning is 14. It was 20 yesterday afternoon. So it's not much more than the temperature of the air around, but a little bit more. So there's a little bit of decomposition going on there, bacterial, which is what makes the heap. But also, in addition to that, there is the fungal decomposition. And I think probably that's more of a factor in giving us that lovely result. So that's not hot composting, whereas what we're looking at here more now, although it's wood, is kind of hot composting, where we have a heap that's over 50 degrees centigrade, and it's been here only for 19 days. And I'm just going to open it up a bit just to show you. So when the tree surgeon brought this heap, he said, do you want this? He said, it's a lot of conifer, Leylandii, and it's a lot of the green leaves. And I said, yeah, definitely, because when it's green like that, that's going to compost more readily, more quickly. And I'm actually looking for it to become more like compost. So here we can see, you can see the steam coming off. And there is good breakdown happening in there. It's pleasantly warm. It's also moist. And this is a big factor in achieving good decomposition of woodchip, because somehow wood seems to dry out all the time. It's partly, I think, the steam coming off when it's warm. It doesn't really hold much moisture wood, but you do want it to be damp in order for it to decompose. So we do water these heaps occasionally. This summer, not, because it's been so dry that all the water's been going on the beds. But if I ever have any spare water, which is actually this week recently, we did put some on this heap and we turned it. And that wasn't deliberate. It's because the tree surgeon dropped it here. And I wanted this space for a second drop of woodchip. So Adam and I, just using shovel, moved it to there. And that has helped the decomposition. You could either use this kind of stuff. It'd be brilliant path mulch in the autumn in that sort of state. And it's going to rot in quite quickly to the soil and enrich the soil of the paths. And path soil is really valuable because plants are rooting into it all the time. It's not dead soil just because you're walking on it. So that's why I value mulches like that for path. Or if you left this another year, it'll probably turn into something like we saw there, options. And then the question of the conifer, there's big belief that pine needles or any kind of coniferous wood will acidify soil. Take pine needles as an example, that's Pinus sorbus. And there's a study you can see on the internet by the University of New Hampshire in 2019. And they looked at this and measured pH. And basically what happens is the decomposition of pine needles or this kind of thing, the decomposes in the heap and take away the acidity. I don't understand how that happens, but you end up with a compost that's not highly acidic. It goes from 3.5 maybe to six, something like that. It's not going to acidify your soil. There's long-term studies show this. Certainly I'm finding it here where we're using quite a bit of this kind of woody mulch. So the essence of that is you don't need to worry about where your wood comes from. Any kind of wood is good. Wood is such a fantastic resource. And we're going to have a look as well at a heap that was delivered a little bit before this one, just to show the contrast. This heap arrived on the 19th of June, that's 10 weeks ago. So it was hot, 60 degrees centigrade when it came and I had a space here, which had been a heap of cow manure, in fact. So it was all ready to receive it, but it wasn't quite big enough for this load. This is one drop. And so I need to shape it up a bit at the side. So this is more in the middle of the garden. It's a bit more windy here. You might be hearing that on the microphone. And it also actually raises the question of where do you store this chip if you want to keep it for a long time? You know, you need space, obviously. And I've got little pockets of ground dotted around the garden. Here, the edge of the heap was on top of some quite vigorous perennial weeds. And then I can see some bindweed pushing through there, for example, some couch grass further up. So that's something to look out for. When we're using this, we'll be careful to pull out any bits of bindweed root or anything like that. It's not going to spoil it. We can pick them out. So this was quite green wood as well, but it's chip, not shred. And it's had a lot of tree leaves in. So I don't know how that came about, but I think that was a factor. It definitely got hot and for longer than other wood that I've had. And it was 60 degrees centigrade for a good three weeks. And let's see what it's turned into. Ah, yeah. I haven't really had much of a rummage in here. That, it's kind of looking almost like, well, going towards compost. What we could do with one like this is use it as an ingredient material for adding to compost heaps as a brand. But again, I would sieve it out because we don't want the bigger bits like that in the compost heap. Yeah, they'll break down eventually, but not in the shorter term that I'm looking for. There's a lot of good stuff in here. So this could be left for longer to turn to compost, but again, it would need some sieving or use on a pathway. Be almost a bit of a waste actually. There's so much compost in here, I think. But yeah, it's just one of so many options that we have with wood chip. So Minty's come to join the fun. What we're looking at here is a different kind of chipping. It's actually shredding. So it's wood shred, a much bigger machine that kind of pulverizes. It pushes the wood through. Now we're just going to have a look, Minty, at that. And it comes through as long, thin strips if it's actual wood. Another word for this is ramial. Bois ramial, chopped up. So ramial is a French word, which means branch. And it's branches that have been less than three inches in diameter. That's a technical term for it, 75 millimeters. And there's quite a lot of green as well. So it's green wood. What does green wood mean? It means wood that's grown in that year. We're now at the end of summer. So everything in here is wood that's grown since March. And it's already turning quite woody. There might be some slightly older wood here. I think some of this is a bit older. There's a lot of young wood. And that's why, one reason why anyway, 65 degrees centigrade. So it's really composting. And it's been here only three days. So that's another reason why. And another reason why is because I thought, right, I'm going to make a proper compost heap of this one. It feels special. And see whether it can be turned into something like compost pretty quickly, maybe within, well, within a year anyway. And let's just have a quick look. And you'll get a view of the steam, I hope, coming out. You know, you see that's really working. And you can also see, oh, it smells gorgeous. It's kind of fruity almost. That's amazing. Fermenting wood. Most of it is pretty fine. That's hot enough that I could only just handle it. And the bits that are, they're long, thin strips, not chips, not cut across so much. And that means there's much more surface area. And it's the surface area that speeds up the decomposition. It's the same in any composting process where you always want to be cutting up the woody bits. Not put them in length, also slice them. I like to slice at least diagonally. That way you get a bit of the shredding effect as well as cutting. And with a heap made like this where we've also got cardboard lining there, that's going to hold in the temperature right to the edge. There's probably enough moisture in there for now, but I reckon this could do with watering perhaps in a month or so. I'll check it for moisture. All that steam coming off, you know, it's losing moisture all the time. And yeah, we'll see this in a future video for sure. How all of these different piles compare. And if we are filming when we're using these, I'll just mention, I'll refer you back to this video because this is kind of like the starting point. I can show you some finished result, which is what we saw at the beginning there of beautiful compost. But it is a longer term process than normal composting. I reckon to use my compost that I make normally from a bit of wood, but not so much, some green as well within about eight to 10 months. And this is more like at least a year, two or three if it's big pieces.