Make Your Soil Blocker
Almost every part of your blocker can be salvaged.
Paint cans, medicine bottles, or just about any
smooth container will work for the cylinder. The
eye bolt serves as a plunger handle, and you could
just as easily use a long bolt with a wooden handle.
The bakery containers are convenient trays, as
they come with clear lids and are reusable.
1. Make the cylinder.
You can make soil blockers any size you want,
depending on the seeds you have. A 2" block
(½-pint can) is best for most seeds. We like the
4" size of the quart can for large seeds like squash
and beans. Smaller blocks are good for starting
faster-growing, smaller seeds like lettuce, greens,
and onions. If you go with a smaller can, you may
want to reduce the size of the eye bolt as well,
cutting it down to 3"– 6" long.
The main thing with the can selection is to avoid
a corrugated can, like a soup can, as the soil won’t
release easily. Before starting, be sure to clean the
Using the hacksaw, cut off the bottom of your
1" to ¼" from the bottom. Cut slowly,
and make sure you get a good, straight cut. The
can bottom will become the plate that presses
the soil blocks.
2. Make the press plate.
With your pliers, go along the edge of the cut-off can
bottom and bend the
1"–¼" remaining part of the
can toward the center. This should give you a nice,
smooth circular plate without any sharp edges.
Mark the center of your plate, then drill a hole at
your center mark, starting with the
1" drill bit for
a pilot hole, and then stepping up to your
Drill a hole in the center of the lid, and trim it to
fit within the cylinder if necessary.
3. Assemble the plunger.
Put one nut on your eye bolt, and thread it about
1½" to 2" from the end of the bolt. Place a washer
on the eye bolt, followed by the lid of the can. If the
lid has a protruding rim, make sure the rim faces
the eye of the bolt.
Now, slide on your press plate and follow it with
a washer. Thread your last nut onto the eye bolt.
The very last nut should be flush with the tip of the
bolt. Tighten the first nut back against the last nut
you put on, sandwiching the other parts tightly
between (Figure A, following page). You should
now have a very stable plunger (Figure B). This
plunger slides inside the main cylinder of the can.
NOTE: If you’re making a bigger blocker, put
2 nuts on the tip to make a deeper depression
for larger seeds.
Press Your Own Soil Blocks
4. Mix the soil.
This recipe (below) is almost foolproof. One “unit”
can be any sort of can or bucket, depending on the
amount of soil you need (start small). There are lots
of different recipes online, so feel free to experiment. You can also buy commercial mixes, but we
haven’t tried those.
Sift all ingredients before mixing. Mix the peat
with the lime or wood ash first. Mix the sand or perlite with the fertilizer. Then mix everything together.
ELIOT COLEMAN’S ORGANIC SOIL RECIPE
30 units peat
1 unit lime or ½ unit wood ashes
20 units coarse sand or perlite
¾ unit organic fertilizer (equal parts blood meal,
colloidal phosphate, and greensand)
10 units good garden soil
20 units well-aged compost
5. Set up a nice large work area.
You’ll want a hard surface like a concrete slab to
dump your soil mix on, and then another area to
keep your trays and blocks once they’re made.
Dump your mix onto your hard surface. Patios are
good for this, as well as outdoor worktables.
6. Wet your mix.
Be careful with this step, as most people won’t
add enough water initially. You want your mix
thoroughly moist, almost dripping water. If your
materials are fairly dry, a good ratio is 3 parts mix
to 1 part water by volume.
Make a large pile of your wetted mix. The pile
should be an inch taller than your blocker.
7. Press a soil block.
Place the plunger into the cylinder of your blocker.
The eye should come through the top toward you.