DIY Soil Wetting Agent Recipe for Improved Plant Hydration

A homemade wetting agent reduces water surface tension, improving infiltration in hydrophobic soils.

Recipe

• 1 gallon (3.8 L) water
• 1 tablespoon (15 mL) liquid dish soap (non-antibacterial, non-degreasing, e.g., plain Dawn)
• 1 tablespoon (15 mL) isopropyl alcohol (70%) or rubbing alcohol
• 1 teaspoon (5 mL) Epsom salt (magnesium sulfate – provides Mg/S)

Instructions

1. Combine in a large container.
2. Stir gently to dissolve (avoid excessive foaming).
3. Apply to soil around plant base (not foliage) during watering.
4. Use fresh; do not store long-term (soap degrades).

Mechanism & Cautions

• Surfactant (soap) lowers surface tension → water penetrates hydrophobic organic matter.
• Alcohol enhances penetration.
• Test on small area first – some plants sensitive to surfactants.
• Overuse → soil structure damage, root toxicity, salt buildup.
• Commercial wetting agents (yucca, polyacrylamides) are more consistent and safer for regular use.

Best for occasional use on water-repellent potting mixes or dry garden beds.