Sawdust as organic component of substrate?

[jeanluc83]

I have access to large quantities of sawdust and was wondering if it could be used as the organic component for substrate?

To be clear I am talking about sawdust from a sawmill. This sawdust is more like very fine wood chips. It could easily be sieved to remove both the very small and large particles. It is almost all pine and most of it has aged a minimum of 5 years.

Most of what I have been able to find has indicated that sawdust can deplete nitrogen and raise acidity. Is this still a problem if used in small amounts?

 

[Poink88]

How much is "small amount"?

What fertilizer are you using? I use pine bark on mine which also deplete N but I regularly use high N fertilizer so I do not worry about it.

 

[PaulH]

I wouldn't risk it. If you keep a compost pile add the sawdust gradually to that with plenty of nitrogen and use it in your garden. If your bonsai have any value to you, why experiment?

 

[Don Blackmond]

I have access to large quantities of sawdust and was wondering if it could be used as the organic component for substrate?

To be clear I am talking about sawdust from a sawmill. This sawdust is more like very fine wood chips. It could easily be sieved to remove both the very small and large particles. It is almost all pine and most of it has aged a minimum of 5 years.

Most of what I have been able to find has indicated that sawdust can deplete nitrogen and raise acidity. Is this still a problem if used in small amounts?

The larger question is why would you want to do this? What are you trying to achieve?

 

[jeanluc83]

The main reason I ask is that I have a free and virtually unlimited supply. So I figured why not.

I also found the following in an interview with Nick Lenz:

"My organic is from the local good-old-boys - eroded sawmill chips and planer shavings"

The complete article can be found here http://bonsaijournal.com/nick-lenz-profile.php

 

[chansen]

I'm not sure what impact it may/may not have on tree roots, but walnut sawdust contains a natural herbicide. I would be super cautious. And besides, the organic component (should you choose to add one) is probably the cheapest to buy. So unless you're maintaining a large collection of trees, it's probably not going to save you much.

When I very first started, I couldn't find lava rock close by and my wife and I were still in college and super duper poor. I bought some of the big lava nuggets and smashed them up. It took forever! The funniest part... there's a HUGE lava supplier about 1.5 hours from where we were at the time. Last time I went, the guy let me fill up as many boxes and buckets as I wanted for $20. 70 gallons of lava later, we were on the road.

The point is... there are often ways of getting an ideal mix with local components if you just keep looking. I like the idea of sawdust because you're using local components that aren't pricey (although I do love me some akadama, nothing local or cheap about it!), but I would keep looking.

 

[Smoke]

I have access to large quantities of sawdust and was wondering if it could be used as the organic component for substrate?

To be clear I am talking about sawdust from a sawmill. This sawdust is more like very fine wood chips. It could easily be sieved to remove both the very small and large particles. It is almost all pine and most of it has aged a minimum of 5 years.

Most of what I have been able to find has indicated that sawdust can deplete nitrogen and raise acidity. Is this still a problem if used in small amounts?

Buy a composter and compost the stuff. It will be awesome stuff. 70/30 grit and composted sawdust for conifers and 50/50 grit and composted sawdust for deciduous.

After that adjust your watering schedule to meet the demands of the organic mix and be prepared to do whatever is necessary. The alternative is rotton roots. Just be vigilant and observant and it will serve you well. Water everyday and you could kill everything. You will be more of a slave......

 

[Don Blackmond]

The main reason I ask is that I have a free and virtually unlimited supply. So I figured why not.

I also found the following in an interview with Nick Lenz:

"My organic is from the local good-old-boys - eroded sawmill chips and planer shavings"

The complete article can be found here http://bonsaijournal.com/nick-lenz-profile.php

ok. But do you have a specific need for organic material in your bonsai soil? What is the purpose? Dirt is free too, but why would you want to put that in your bonsai soil.

Unless you have a reason to do it, I would suggest not adding sawdust to your soil. Of course I am biased. I don't add any organics in my soil unless there is a specific purpose to be served. For instance, soil for a bald cypress where moisture and muck is a positive and not a negative.

 

[Poink88]

After that adjust your watering schedule to meet the demands of the organic mix and be prepared to do whatever is necessary. The alternative is rotton roots. Just be vigilant and observant and it will serve you well. Water everyday and you could kill everything. You will be more of a slave......

Actually, wouldn't he be more free if he doesn't have to water daily?

In my mind, those who have to water daily or multiple times a day are the ones more closely tethered to their garden (slave as you termed it).

 

[jeanluc83]

besides, the organic component (should you choose to add one) is probably the cheapest to buy

Yeah but I hate to turn up free.

But do you have a specific need for organic material in your bonsai soil?

Walter Pall’s article on feeding substrate and watering he notes that the organic component should comprise 15-20% of the volume. He uses rough peat but also says that chopped bark would work. I was wondering if sawdust would fit the bill. Again this is not fine sawdust but rough sawdust from a sawmill.

 

[Poink88]

Walter Pall’s article on feeding substrate and watering he notes that the organic component should comprise 15-20% of the volume. He uses rough peat but also says that chopped bark would work. I was wondering if sawdust would fit the bill. Again this is not fine sawdust but rough sawdust from a sawmill.

Soil mix is one of the most debated topics in bonsai...as they say, ask 10 bonsai folks and you will get 12 different answers.

Experiment and see if it works for you. Share your thoughts after but be prepared to be questioned (or even attacked) from all angles. A few will listen thought and be delighted to hear your results.

You've done your homework and know what to avoid or compensate for. I say try it.

Good luck!

 

[dick benbow]

My input would be to make the effort to involve a tree or two in various % experiments and find out by actual involvement.
you have component % input and know about nitrogen loss, so that can be compensated for.
Our supplier of bonsai needs offers their own soil, that seems to work for the wet NW. One third each of bark, volcanic, pummice.

 

[jeanluc83]

Thanks for all the responses.

Experiment and see if it works for you.

I knew it was only a matter of time.

I guess I will need to do some experimenting. Since I am just starting out I think I will stick with tried and true for now. Maybe in a couple of years I'll do some trials and see what happens.

 

[greenman63]

Sawdust as substrate for culinary mushrooms

You might be able to sell your free sawdust to people who cultivate culinary mushrooms. They often use different woods for substrate with different kinds of fungi, according to species or habitat.

 

[Alain BERTRAND]

Sawdust has been the object of experiments for "classic" nursery because theses people use quite a lot of organic matter in their mixes.

In summary, it uses to much nitrogen and (it is linked) it is not dimensionally stable. In almost any aspect it is inferior to pine bark and that is why it is not used.

 

[crust]

organic component

For more 25 years Lenz used exactly this stuff as his organic component--so did I. Theses where years when he produce many, many world class bonsai, all grown fundamentally with carefully composted saw chips (saw mill saw dust), Turface and a some grit--and a few other things. He is a expert in growing fragile plants in a organic based media. One must water and fertilize in a controlled way and watch PH. It is just a different mode. I have some of my plants, western pines and some others, in a porous lava/pumice substrate with little organics such as Walter uses but all my deciduous and larch still go into a relatively fine organic base mix that includes composted saw chips/dust or composted soil conditioner, aka ground bark. Composting the stuff requires a little knack. The big pain is sifting it to remove the fines. I use a 1/8" screen and a window screen. I compost mine in a garbage can. I first soak it in full strength Miracle grow. Then drain it and put it in a in a holey garbage can and keep it warm and let it sit for a couple weeks. Turn it and dampen it with some compost tea and organic fertilizer water and let it set again--don't make it soppy--just damp. It will darken and smell good--then it is ready. If you dry it it will stop rotting for use later. I always used a wetting agent to dampen it before use.

 

[jeanluc83]

For more 25 years Lenz used exactly this stuff as his organic component--so did I. Theses where years when he produce many, many world class bonsai, all grown fundamentally with carefully composted saw chips (saw mill saw dust), Turface and a some grit--and a few other things. He is a expert in growing fragile plants in a organic based media. One must water and fertilize in a controlled way and watch PH. It is just a different mode. I have some of my plants, western pines and some others, in a porous lava/pumice substrate with little organics such as Walter uses but all my deciduous and larch still go into a relatively fine organic base mix that includes composted saw chips/dust or composted soil conditioner, aka ground bark. Composting the stuff requires a little knack. The big pain is sifting it to remove the fines. I use a 1/8" screen and a window screen. I compost mine in a garbage can. I first soak it in full strength Miracle grow. Then drain it and put it in a in a holey garbage can and keep it warm and let it sit for a couple weeks. Turn it and dampen it with some compost tea and organic fertilizer water and let it set again--don't make it soppy--just damp. It will darken and smell good--then it is ready. If you dry it it will stop rotting for use later. I always used a wetting agent to dampen it before use.

I guess I’m not crazy (at least my question isn’t).

Much of the sawdust has been self-composted for at least 5 years is some areas much longer. Would you still consider the above treatment necessary?

 

[bougie nights]

If you have an abundance of this, perhaps you can compost it as described, and create some raised beds using it as a component of a medium for rapidly growing out smaller stock. Add some perlite and sand maybe.

 

[crust]

I guess I’m not crazy (at least my question isn’t).

Much of the sawdust has been self-composted for at least 5 years is some areas much longer. Would you still consider the above treatment necessary?

Not so much would be required but I would still dose it with some fertilizer because the action of decomp depletes the nitrogen to the point of sterility, then dry it and sift it. Most people don't have the time or inclination for this. Some just assure that its mostly coarse and use it damp. Once mixed with the other soil components it dries up and can be given a quick sift as used too.

 

[Bill S]

I guess I’m not crazy (at least my question isn’t).

Much of the sawdust has been self-composted for at least 5 years is some areas much longer. Would you still consider the above treatment necessary?

Just sift out the fines, we/me our club uses 1/3 composted pine bark haydite, and turface.

We sell a 5 gal bucket for $35, do you belong to one of the Ct clubs??