Charcoal in Soil for Tomato Plants
- Charcoal briquettes that are labeled as made from 100 percent hardwood are best as garden amendments. Some briquettes have binders or other additives, which can actually be harmful to plants. Check labels for any additives.
- Place your charcoal briquettes in a sack, preferably a gunny sack or something similarly sturdy, and hit the briquettes with a baseball bat or something similar. Crush your briquettes into granules approximately 1/8th inch in diameter.
- Spread the ground charcoal evenly over the soil where you will be planting your tomatoes. There is no evidence as of yet as to how much charcoal constitutes the proper amount, but adding approximately 5 to 10 percent to the top 6 inches of soil would be appropriate.
- Till your charcoal and any other soil amendments, such as organic compost, into the top 6 inches of your garden soil. Break up dirt clods so the soil is ready for the tomato plants or seeds to be added. Plant and water as usual. There is no need to treat your tomatoes any differently because charcoal has been added to the soil. Tests have shown that adding charcoal to the soil can improve tomato yield by as much as 9 percent.