Hi,This is sort of permaculture/tool library/urban farm related, I'm putting it in the urban farm discussion forum as it seems the best place...
I need to do some sheet mulching on my blackberry-cane-infested side yard. In the past for my mulching projects I've used mulch from tree trimming companies since they will deliver as much as you want for free (as long as you're willing to take a "truckload", doable with a few neighbors splitting). I've always used stuff from Seattle Tree Preservation as they seem cool and are nearby (35th and lake city).
So the problem....
Their pull-behind-a-truck chipper/shredder is designed to chip branches up to 12" and it's output is _very_ course. Long lengths(12 to 18") of thin branches can make it through the chipper no problem. So when I have used them to mulch the smaller stuff tends to break down pretty quickly and then I am left with lots of the sticks on the surface.
I am wondering if the tool library has a chipper/shredder yet. I was thinking maybe if the course stuff was feed through a smaller chipper/shredder it would make it more consistent/homogenous. Does this seem like an OK idea or would their be problems feeding stuff back through? Anybody have other ideas how to solve this? I've thought about sieving it but that would be _really_ labor intensive unless you had some sort of rotating screen type sieve.
My other idea for the free wood chips is to convince the tree trimmers to split their trucks down the middle and sort deciduous and coniferous chip so that we might using them for growing edible mushrooms :)
I know what you mean when you describe all those stringy twigs in the Arborist Chips. I generally hand pull them as I find them while moving them, and rake them up with a metal leaf rake as the final step in spreading them. Normally they then go into the Yard Waste bin, where I let Cleanscapes process them.
Yes, the Tool Library has a Lescha ZAK 1800 Chipper, but it is out of service temporarily for a bad switch. It is not the best solution to your problem however, because it is low powered and noisy. Once wood has dried, even partially, it becomes much more difficult to chip. This causes a lot of wear and tear on the chipper blade. The dullness is in part the reason for the twigs in the first place, as Arborists often are behind in their chipper maintenance. Branches get sucked through without being fully chipped. The Lescha also draws a lot of electricity, to the point of often blowing circuit breakers. I used to own one, but like the one donated to the Tool Library, I got rid of it. So what's the solution?
The first recommendation I have is to ignore them, after all they will decay, plants will over grow them and who cares? That having been said, what other choices are there?
These twigs would be ideal for Bio-Char, a process of wood gasification that reduces the wood to nearly pure carbon. This is the basis of the Swidden Agriculture in tropical forests. Art Donnelly and Larry Davis teach classes where you can make a bio-char stove out of a 5-gallon metal bucket, in which these twigs would be converted into a wonderful resource for your garden. Check out their website: http://seachar.org
You can do as I do and put them in Yard Waste, but you could also gather them and place them in out of the way places as small piles. Twig piles are an extremely valuable habitat provider for many lifeforms that share our gardens. The insects and spiders that live here form the next step up in the food chain that feeds birds and eventually larger predators (like cats, unfortunately). Over time they will decay, but in the meantime they provide service. The Washington State Department of Fish and Wildlife is a great resource for landscape design ideas: http://wdfw.wa.gov/living/landscaping/#backyard
Finally, I love your idea about growing mushrooms, and yes it would be ideal to sort through different types of chips. You can probably develop a relationship with an Arborist who can get you a more specific load. If you haven't already read Paul Stamets' book, Mycelium Running, it is highly recommended. Paul goes into great detail about the importance of chips in the forest ecology and his company provides a wealth of spawn. http://www.fungi.com/home.html
Good luck with your endeavor and Green Wishes, Keith
wow thanks for all of the great info Keith!