Acidifying Soil for Container Blueberries in Southwest Florida

Blueberries need pH 4.5–5.0. In Southwest Florida's alkaline soils, create the right mix in containers:

Best container mix:

• 50% sphagnum peat moss (naturally acidic)
• 25% pine bark fines (acidic, improves drainage)
• 25% perlite or coarse sand
• Mix in 1 cup elemental sulfur per cubic yard of mix

Alternative acidifiers:

• Calcium sulfate (gypsum): Lowers pH, adds calcium, safe to plant immediately. Use 1–2 tbsp per gallon of mix.
• Soil sulfur (elemental): Works slowly via microbial action. Apply in fall, wait months before planting.
• Aluminum sulfate: Fast-acting but can build up toxic aluminum—use sparingly.

Maintenance: Mulch with pine needles. Fertilize with acid-forming fertilizer (e.g., ammonium sulfate). Test pH annually. Water with rainwater or acidified tap water (1 tbsp vinegar/gallon).

Resource: avant-gardening.com for detailed soil-building guides.