First some background on railroad or cross ties. This might be a little excessive, but I found it wild how many ties are used per mile.
“A railroad tie/railway tie/crosstie (North America), or railway sleeper (Europe, Australia & Asia) is a rectangular support for the rails in railroad tracks. Generally laid perpendicular to the rails, ties transfer loads to the track ballast and subgrade, hold the rails upright, and keep them spaced to the correct gauge.
Railroad ties were traditionally made of wood, but prestressed concrete is now widely used especially in Europe and Asia. Steel ties are common on secondary lines in the UK; plastic composite ties are also employed, although far less than wood or concrete. As of January 2008, the approximate market share in North America for traditional and wood ties was 91.5%, the remainder being concrete, steel, azobé (red ironwood) and plastic composite.
Up to 3000 ties are used per mile of railroad track in the USA.” – wikipedia
Are ties a good choice for raised beds?
Railroad ties have a preservative known as creosote applied to them. You may also notice this same substance on power line poles. Creosote has been shown to be uptaken by plants. The following article produced by MSU Extension Water Quality program details this here. Per the article, “Plants have shown only limited potential to take up creosote but some compounds have been shown to attach to roots, which could lead to elevated creosote levels on tuber vegetables. For this reason, it is advisable not to landscape with railroad ties directly in contact with vegetable gardens.”
Here’s another interesting quote from EPA’s website, “Creosote is a wood preservative used for commercial purposes only; it has no registered residential uses. Creosote is obtained from high temperature distillation of coal tar (itself a mixture of hundreds of organic substances), and over 100 components in creosote have been identified. It is used as a fungicide, insecticide, miticide, and sporicide to protect wood and is applied by pressure methods to wood products, primarily utility poles and railroad ties.”
In Farmer Dawkins opinion, it would be best if one can avoid the use of railroad ties around plants they intend to ingest.