How to Use Chlorine Bleach to Control Fungus on Seedlings

Chlorine bleach can help reduce the risk of fungus attacking young seedlings. Many pathogens, such as root rot fungus, black rot or damping-off disease attack sprouting seeds and seedlings, causing them to be stunted or even die before becoming well established. A simple solution of regular household bleach and water can reduce the risk from these pathogens and improve the chances for your young plants. Soaking the seeds in the solution before planting kills the spores of the fungi to greatly reduce or eliminate the risk of infection to growing seedlings.

Things You'll Need

• Household bleach
• Bucket
• Cheesecloth or loosely woven cotton bag

Instructions

1. Make a solution of one part household bleach with three parts warm, but not hot, water -- around 100 degrees Fahrenheit. Mix the solution thoroughly. Prepare 1 gallon bleach solution for every pound of seeds.

2. Place the seeds in a cheesecloth or loosely woven cloth bag. Soak the seeds in clean water for several minutes to wet the seeds thoroughly.

3. Soak the seeds in the chlorine solution for one to two minutes. Agitate the seeds during this time to allow the solution to reach the surface of all the seeds.

4. Remove the seed bag from the solution. Rinse the seeds thoroughly in clean, cold water. Open the bag and spread the seeds out evenly. Allow the seeds to air dry before planting. If desired, treat the seeds with an additional fungicide at this time.

5. Dip any seed trays or other planters in the solution to kill any pathogens on the trays you use to grow the seeds. Rinse the trays thoroughly to remove any chlorine residue.

Tips & Warnings

• When planting seeds, use a pretreated and sterilized seed starter soil mix to help prevent fungal spores from infecting germinating seeds and seedlings from contaminated soil.

• Chlorine is a powerful oxidizer that can irritate skin, eyes and mucous membranes. Always wear eye protection and gloves when working with strong concentrations of chlorine bleach. Avoid contact of chlorine solutions on fabrics or other surface to avoid damaging them.

References

• University of California; Chlorination in the Production and Postharvest Handling of Fresh Fruits and Vegetables; Trevor Suslow
• North Carolina State University; Starting Plants From Seeds; Erv Evans, et al.
• University of Illinois Extension; Vegetable Seed Treatment; March 1992
• University of Alaska; Seed Starting and Transplanting; Wayne Vandre