11 years ago, when i was in my first season of transplant production in detroit, i didn’t have a lot of time to build equipment, we just needed to start transplants.
we decided to make our soil mix from all raw parts, purchasing peat and perlite and other materials and then combining them together. the previous farm where i worked we had a cement mixer that was used for mixing soil, but without that luxury we tried other methods, including filling a barrel with materials and then rolling it all the way down the greenhouse and back. this proved to be a lot of work and to not work very well. we settled on a simple “mixing box”, little more than a platform with three sides you can see the original here. i slapped it together from what was laying around and didn’t really give much thought to design. one very silly aspect of it’s design included mounting support “L” brackets on the inside which would catch on the shovel as you mixed. i swore for years that i would put a fix to this and rebuild the box in such a way that it would not be nearly so frustrating, and yet i never did. until this year.
since i was making improvements, i figured why not make more. one thing that i had noticed is that people liked the platform to be raised off the ground, sticking milk crates under it to raise it up. i also noticed that we often were slowed down by the fact that we filled trays/made soil blocks out of the same mixing box, what if we had a separate potting bench just for filling trays and making blocks?
after making the improvements i can’t believe it’s taken me so long to do them. i need to be more proactive about making these improvements in the future.
to put together the box i worked with what i had, some 4×4’s and 2×6’s, and purchased two sheets of 3/4 inch plywood, and some metal corner brackets. i think i over built it, the whole thing could have been made with 1/2 plywood and 2×4’s but i figure the last box was used for 10 years might as well make it sturdy. the boxes are both 4×4 feet, the mixing box is 10 inches off the ground the potting bench 2’8″ off the ground.
the boxes are not attached to each other so if you need to move them you can do so easily, or if you want to arrange them in a different format you can switch them up. we increased the height of the sides to 12 inches so that you don’t have soil coming over the edges as easily and sloped the left side of the potting bench so that when you shovel soil from the mixing box to the potting bench you don’t have to lift the shovel as high.