Using 15-20 Year-Old Railroad Ties in an Organic Vegetable Garden: Safety Considerations and Alternatives

When it comes to framing out raised beds in an organic vegetable garden, using 15-20 year-old railroad ties can present some risks due to the potential presence of chemicals. Historically, railroad ties were treated with creosote, a coal-tar derivative that is toxic and can leach into the soil. Even if the ties are older, there is still a risk of chemical leaching, especially if they are weathered or cracked. This article will explore the safety concerns and suggest safer alternatives for your garden.

Chemical Treatment Concerns

Historical Chemical Usage: Creosote has been the most common treatment for railroad ties. This tar-based preservative is known to be toxic and can leach into the soil over time. Even after decades, there is a risk of chemical leaching, especially if the ties are no longer in good condition due to weathering or cracking.

Alternatives to Contamination

Untreated Wood: If you want to avoid potential contamination, consider using naturally resistant timber such as cedar or redwood. These wood types are naturally decay-resistant and do not require chemical treatments. Composite Materials: Composites made from recycled plastic and wood fibers are another good alternative. These materials are durable and do not pose chemical risks. Stone Bricks or Concrete Blocks: These materials are safe and will last for a long time without needing any chemical treatments. They can add an aesthetic appeal to your garden while ensuring safety.

Testing for Contaminants

Even if you decide to proceed with the use of old railroad ties, it may be wise to have the soil tested for contaminants after the installation of the ties, especially if you notice any signs of deterioration. Testing can help you assess the potential risks and take necessary precautions.

Additional Safety Measures

Internal Barriers: If you still choose to use the ties, consider lining the interior of the raised bed with a barrier such as landscape fabric or plastic sheeting. This can help prevent any chemical leaching into the soil, thus minimizing the risk.

Industry and Academic Perspectives

Expert Opinions: Different experts and organizations have varying opinions on the use of old railroad ties. For instance, Pattie, in a discussion on the Garden's Alive website, found that badly rotted timbers might be treated with arsenic or other toxic preservatives. This led to an EPA warning that creosote-treated wood is not intended for residential use and is illegal to use in home landscaping.

On the other hand, the UC Davis website, a reputable source for agricultural science, is less alarmist. They suggest that using railroad ties in the past, stacked two high and overlapping with steel supports, was a common practice. They do not discourage the use of old railroad ties but suggest caution and the use of barriers to prevent any potential contamination.

Conclusion

While it might be possible to use 15-20 year-old railroad ties in a raised bed garden, the safety concerns associated with chemical leaching make it advisable to consider safer alternatives. These include untreated wood, composite materials, stone, or concrete blocks. Proper testing and the use of internal barriers can further mitigate any risks. Ultimately, the decision should weigh both the benefits of using old ties and the potential health and safety risks involved.