By Allen Dong, I-Tech, PO Box 413, Veneta,
Here is a design for making
a hand held weeding spade to weed between
plants, such as a bed of garlic. The weeding
spade was made from a masonry "pointing"
trowel (Figure 1) by notching and sharpening
the edges of the trowel. The advantages of
using a "pointing" trowel to make
the weeding spade include:
High quality towels have
very strong and hard blades made of tool
steel that cannot be sharpened with file.
A high quality trowel will hold a sharp
edge better than a hand hoe blade that
can be sharpened with a file.
Compared with a hand hoe,
less effort is required for working a
trowel blade below the soil surface because
the towel blade is thinner. For example,
the Marshalltown pointing trowel blade
(model 45-5 and 45-6) is 0.05 inch thick
near the handle and 0.025 inch thick near
the point; compared to the Ames hoe with
a 0.1-inch thick blade.
trowel blade provides both a narrow edge
and a broad edge for weeding between plants.
Grind notches (1/8 inch wide,
spaced 3/4 inch apart) on the edges of the
trowel using an angle grinder (Figure 1).
The notches permit hooking and tearing of
the weeds. The edges of the trowel are beveled
sharp with an angle grinder, or a grinding
wheel. Be careful not to grind the blade at
one spot for an extended period (more than
1 second). Otherwise heat will build up, changing
the steel color to blue and the steel may
become brittle at that spot. The grinding
can also be done at shops that sharpen knives,
scissors or saw blades. Cost of a six-inch
masonry "pointing" trowel is $3-10,
depending on quality of steel, thickness of
blade, and manufacturer.
1. Angle grinder for modifying the trowel;
masonry "pointing" trowel; and
a weeding spade.
( Acknowledgement: Technical assistance
from Emeritus Professor William Chancellor,
University of California, Davis and Roger
J. Edberg, University of California, Santa
Hand Hoe and Mower Blades
By Allen Dong, Jane Edberg and Roger J. Edberg,
I-Tech, PO Box 413 Veneta, OR 97487
The hand hoe uses a sharp straight edge to
cut plant roots and stems. The hoe can be
improved by grinding slanted grooves on its
cutting edge (Figure 1). The grooves give
a serrated edge to the hoe and keep the plant
from sliding out of the cutting edge as it
cut and tear. This modification can be made
with a hand-held electric disk grinder or
A hand-held electric disk grinder with a
4 1/2 inch (114 mm) diameter by 3/16-inch
(4.8 mm) thick grinding disk is used (Figure
2). The grooves are approximately 1/32 inch
(0.8 mm) deep by 5/8 inch (16 mm) long, spaced
1/2 inch (13 mm) apart and ground on the flat
side of the hoe that faces the person. Compared
with the beveled side facing the earth, grooves
ground on the flat side of the hoe will not
wear out as quickly and the grooves are not
ground off when the blade is sharpen on the
beveled side. The grooves are slanted away
from the hoe handle. Slants on the left side
of the hoe are mirror images of the slants
on the right side of the hoe. This modification
can be made in less than 2 minutes.
Other applications of serration include rotary
mower blades (Figure 2). For lawn and rotary
mower blades, the grooves are ground on the
flat side of the blade, perpendicular to the
cutting edge and are spaced approximately
5/8 inch (16 mm) apart (Figure 2). After grinding
the grooves, the mower blade must be balanced
to reduce vibration during use of blade.
Acknowledgements: Technical assistance from
Emeritus professor William Chancellor, University
of California, Davis and Phyllis Woodbury,
Top Figure. Hand hoe with grooves.
Bottom Figure. Rotary lawn mower blade,
500 mm (20 inch) (A), rotary mower blades
for 1.27 m (50 inch) cut (B), and hand held