How to Make a Soil Sterilizer

Growing from seed ensures that you have complete control over the life of a plant, but it also means that you are responsible for the tender, early days of the sprouting seedlings. In those early days, bacteria, fungi and pests in the seedling's soil can quickly damage or outright kill the young plants. Sterilized soil helps give the seedlings a fresh start. If you grow plants in pots, you can sterilize small amounts of soil in an oven or microwave, but researchers at the University of Guam have created a way to sterilize large amounts of soil using a 55-gallon drum.

55-gallon metal drum

Clean cloth

Sawzall

Drill with 1/8-inch bit

4 concrete blocks

Wire mesh screen

Plywood

Firewood

Remove the top of a 55-gallon drum with a Sawzall or similar tool. Cut inside the rim of the drum, not through the outer edge -- the top will need to fit back inside the drum later.

Drill 25 1/8-inch holes into the removed drum top at regular intervals.

Rinse out and wipe down the inside of the empty drum to remove any residue remaining from its original use.

Stand two concrete blocks on level ground, then set the drum on top. Leave room to place fire-making materials between the concrete blocks, under the center of the drum.

Sit two more concrete blocks inside the drum.

Add water to the drum until it covers the concrete blocks. Lay the removed drum top over the blocks, then place a wire mesh screen over the drum top to prevent soil from falling into the cut holes.

Sterilize soil by lighting a fire underneath the drum for at least 30 minutes. Cover the drum with a sheet of plywood to prevent heat and smoke from leaving the soil sterilizer.

Avoid touching the metal drum until it has cooled down.

Wear work gloves if the edges of the cut metal top are too jagged.