Growing plants in sawdust

[El Presidente Hillbillios]

i got it as horse bedding. We had a few of us buying it by the truck load at the time. It was just pine shavings. Have to be really carefull sourcing as most is either mdf or particle board dust, both have glue and other nasties in it.

[planthelper]

you have to only ask around solid wood door manufacutures or sawmills.

some workshops will be able so say to you, yes it's only solid wood shavings.

you need to look for the dustbags fitted to machines which only produced solid wood shavings.

[tripsis]

Exactly, that's where mine has come from. There's a couple of places not far from me who produce what I need. Not huge quantities as one might expect from large commercial manufacturers, but enough. One place has (untreated) pine shaving mixed in too, but there's far less pine than hardwood. The other place I'm only going to go to today, so unsure of what it will be like.

Marcel, I'm pretty sure I asked a couple of places on the Northern Beaches who were able to help out, but I didn't follow it up. I'll check if I wrote down the names when I get home later. Bit precious about the places where I'm getting it presently to disclose names though, as it took me ages to find them. If don't need huge amounts, I might be able to pass some on your way every now and then (maybe a garbage bag worth).

[Moses]

Tomatoes get to 10m - 12m tall? Surely you mean feet...

I suppose 8 months is a pretty fast turnaround time, relative to using it in permanent beds.

 

no i meant metres, once they got to about 10 foot they would be lowered on the string they grew up so they lay along the bags of sawdust so yeah the active growth area of the plant was around 10 to 15 feet but the plants actually grow to 12-15 metres, trust me it's a long week driving around a picking frame that is about 12 foot tall lowering plants (25,000 plants)

best bloody tomatoes ive eaten, the king tomato which we would remove could be so big one slice was bigger than a slice of bread and solid flesh not full of watery seeded sections.

i'm trying to get some now to grow.

you can see in this pic the stems running along the grow bags at the bottom

Edited August 24, 2011 by Moses

[ubza_1234]

holy moley! 8O

 

[tripsis]

That's really quite incredible Moses...! I had no idea tomatoes could get so massive. Is that king tomato you speak of a variety? Happen to have spare seeds? Sounds pretty good.

[tripsis]

Alright, what about this idea. Using sawdust as a seedling propagation material? I think it would be perfect. Not likely to dry out too quickly, wouldn't have issues of drawing nitrogen while breaking down as the period it would be used for would be relatively brief and it's a fine texture, so perfect for small seedlings.

[Moses]

That's really quite incredible Moses...! I had no idea tomatoes could get so massive. Is that king tomato you speak of a variety? Happen to have spare seeds? Sounds pretty good.

 

when you grow truss tomatoes like in pic above you'll notice they grow in pairs except at the very top/beginning of the truss, this was always referred to as the "king" tomato and was removed to allow for even growth of the rest of the truss or left on depending on what we were after(small truss of 3-4 large fruit or large truss of 5-6 medium fruit) either way the king was never sold to public the staff would take theses home each week after pick.I had people everywhere waiting for my weekly tomato delivery and often 1 was enough, i would get around 3-4 shopping bags a pick, twice a week.

I cant remember the actual variety of tomato now and sadly don't have seeds....yet.There were always fruit outside of the greenhouses and property so the g.f and I plan a drive by one day to scrounge up some old fruit and regain this variety so i'll keep you in mind when we do.

[tripsis]

Ah, right, got it. So do the king tomatoes naturally grow larger than the others?

Sweet, would be keen if you end up getting some. Should have some seeds of a couple of very good varieties once they start fruiting this season if you're interested.

[tripsis]

For those that proposed treating the sawdust in dilute urine, how dilute does it need to be?

Also, could anything else be used in place of urine?

Edited September 4, 2011 by tripsis

[tripsis]

The more I think about this idea, the more enamoured I am with it.

Found this:

Field studies dating back to the 1950s — and as recent as this year — suggest that a high-fiber diet of woody materials is exactly what many soils need. Rotted bits of wood persist as organic matter for a long time, enhancing the soil’s ability to retain nutrients and moisture, which results in bigger, better crops.

But wait: Woody materials are high in carbon and cellulose, so they need nitrogen and time in order to decompose. If you ignore these facts by mixing fresh sawdust or wood chips directly into your soil, the materials will bind up much of the soil’s nitrogen and render the spot useless for gardening for a season or two.

The outcome changes, however, if you add nitrogen or time. For example, when researchers planted a new organic apple orchard in northern Maine in 2005, fresh wood chips combined with blood meal (a very high-nitrogen organic material with a typical analysis of 12-0-0) and tilled into the top layer of the soil — plus a surface mulch of wood chips — proved better than three other treatments at promoting rapid tree growth. And, in less than two years, the organic matter content in the chip-amended plots went from near zero to 2 to 3 percent.

...

If kept moist, sawdust can decompose surprisingly quickly. In a study at Ohio State University, sawdust rotted faster than newspaper or straw, both of which were still recognizable after 16 weeks. To speed up rotting in a pile of sawdust, simply add moisture and nitrogen. This can be done by mixing up a big batch of fish emulsion, pouring it into an already damp, doughnut-shaped sawdust pile, and then covering it with a tarp or an old blanket to retain moisture. After sawdust turns black, you can use it to lighten up any soil — including potting soil — for seedlings and container gardening.

From the same site:

Sawdust has much more exposed surface area than wood chips do, so incorporating fresh sawdust into soil is not a good idea chemically (because of nitrogen tie-up) or physically (the mixture won’t hold water worth a flip). But sawdust makes a spectacular mulch for perennial crops. As long as you scatter a bit of organic fertilizer, poultry manure or other nitrogen source over the surface each time you throw on a fresh layer, sawdust makes unsurpassed mulch for blueberries, strawberries and raspberries, and it can work well with asparagus, too.

I find that last quote a little hard to believe though. If sufficient nitrogen is mixed in with the soil, it shouldn't matter about nitrogen tie-up. As for water holding qualities, sawdust hold water brilliantly! So not sure what to make of that last quote.

Source.

[Zaka]

Irie,

Well I've been testing out germination in wood shavings.

I have done Nutmeg successfully.

Just tried out Moringa which also did well.

The roots were well developed & easy to remove from the shavings.

Once seeds have started sprouting the plants are then individually potted up...

Respect,

Z

[tripsis]

I definitely see the value of sawdust for seedlings. Even with the associated problem of drawing nitrogen as it break down, I don't think the seedlings would be in there long enough for it to become an issue. Without that issue, sawdust is fine enough to raise seedlings and has good water holding capacity.

[Gunter]

sawdust is an awesome medium, it buffers N too!!!

It also uses the carbon cycle, which is directly related to N turnover!

A lot of people do not understand this, that by putting uncomposted plant material in the root zone you can get better growth results.

the way it interacts with N is an advantage! it ends up slowly releasing the N back, and you can accelerate this buy supplementing soluble carbon, like sugar. It is quite advanced in some ways but really old school, like a forest floor.

All you have to do is add a bit of extra N, it really isn't an issue that N gets tied up.

Consider nature, it puts organic matter down year after year and fertility increases over time, the carrying capacity of a forest increases over time.

This works so well with leafy plants it is funny that more people have not tried it, but you do have to know how to care for it, if you have a sawdust/straw rich garden and then someone cares for it who doesn't know what they are doing things are not going to go well. For example don't top water when you can avoid it, it leaches soluble nutrients away from the plants, meaning that N that is being turned over in the carbon cycle gets washed away before it goes to the plants.

Edited September 4, 2011 by Archaea

[planthelper]

For those that proposed treating the sawdust in dilute urine, how dilute does it need to be?

Also, could anything else be used in place of urine?

 

make up 20l, or whatever ammount you need, of a hydroponic mixture and say twice as strong as recommanded for full grow.

than drench the sawdust (which is stored in big buckets or drums) with the mixture right to the top level.

after two weeks you might drain the fert off into another fresh sawdust bucket.

fresh sawdust can absorbe quite a bit of water.

for seedlings sawdust, i would use normal strengh hydroponic mixture.

the old hydroponic liquid can be used to turn some sawdust into mulch.