If you just can’t find good sawdust locally you can pick up these equine pellets made from pine at farm supply stores. I understand that pellets for the pellet burning stoves can also be used and found cheaper on sale and in bulk.
We use sawdust in our Mittleider garden for our grow boxes and in our seedling trays. Each year we top off the grow boxes before the growing season begins. Today we made the trip over to a nearby town where a sawmill allows us to shovel our own sawdust for free. They make pallets and are largely cutting inexpensive cottonwood trees for the lumber. Any tree expect the black walnut provides a usable sawdust for a Mittleider grow box or seedling tray
The sawdust is mixed with sand for both the grow boxes and the seedling trays. For the grow boxes it is mixed at 3 parts sawdust and 1 part sand. For the seedling trays it is 2 parts sawdust to one of the sand. Both are mixed by volume. I’ll try and take some pictures that show the size of the particles. Too large and too fine are both bad.
No idea how much wood they cut in a week, but this sawdust pile is massive, the picture truly doesn’t do it justice.
A quick trip to Jamesport, MO, today to get sawdust for our seedling flats and grow boxes. This lumber mill makes pallets and will allow us to take the sawdust for FREE. They do not make pallets from walnut so this sawdust is safe to use. We will make a few trips here in the near future.