Lye Contamination in Garden Soil: Assessment and Remediation

Understanding Lye (Sodium Hydroxide) in Soil

Lye (NaOH) is a strong base (pH 13-14). Spilled 3-4 years ago, it has likely reacted with soil components, but residual alkalinity may persist.

Testing and Response

1. Test soil pH in the affected area and surrounding zones. Use a reliable meter or lab test.
2. If pH > 7.5 (alkaline): The lye raised pH excessively. Remediate by:
   • Incorporating elemental sulfur (1-2 lbs/100 sq ft) to lower pH gradually.
   • Adding organic matter (compost, peat moss) to buffer pH and support microbial recovery.
   • Retesting in 4-6 weeks; repeat sulfur if needed.
3. If pH 6.0-7.0: Soil has self-buffered. Proceed with planting; monitor plant health.
4. If pH < 6.0: Unlikely from lye, but amend with lime if needed for your crops.

Planting Considerations

Most vegetables prefer pH 6.0-6.8. After remediation, choose tolerant crops for the first season (beans, peas, kale). Avoid acid-lovers (blueberries, potatoes) until pH stabilizes.

For comprehensive soil building guidance, see Avant-Gardening's soil resources.