What natural fertilizers prevent blossom end rot?
Written by
Benjamin Miller
Reviewed by
Prof. Martin Thorne, Ph.D.Natural fertilizers offer a source of calcium while improving soil health to prevent blossom end rot. Synthetic options seem great, but organic amendments slowly release nutrients that are timed to meet plant needs and are less risky due to reduced chemical burn. I've used them for years, and my tomato harvests were healthy.
Crushed Oyster Shells
- 38% calcium carbonate content slowly dissolves over 3-4 months
- Raises pH slightly benefiting acidic soils below 6.0
- Provides trace minerals like zinc and iron for balanced nutrition
Finely Ground Bone Meal
- 20-25% calcium plus 15% phosphorus for root development
- Microbes break down releasing nutrients during critical fruiting
- Attracts beneficial soil organisms improving soil structure
Gypsum Powder
- 23% soluble calcium available immediately to plants
- Improves clay soil drainage without altering pH levels
- Reduces salt buildup in container gardens effectively
Use Fertilizer Properly. 2: Carefully incorporate amendments into the top 6 inches of soil before planting. For established plants, make shallow trenches around the stems and gently work the nutrients into the soil. Lastly, thoroughly water in the fertilizer to activate nutrient release. I tend to use when I think it's going to rain so it depends naturally.
Combine with consistent moisture management. Calcium is mobile in a plant with water, hence the importance of irrigation. If using irrigation, use a drip irrigation system for even distribution and keep the soil slightly moist, but not saturated or dry. This combination prevents blossom end rot better than fertilizer alone.
Add compost and mulch. Apply 2 inches of finished compost before any fertilizers; this enhances microbial activity. Add straw mulch to retain water and maintain a consistent temperature. My plants are stronger with this method.
Observe plant response every week. New growth should appear dark green, and no leaves should curl. Fruits should develop without leathery patches. Rates of application should be adjusted based on visual observations and seasonal conditions.
Read the full article: Tomato Blossom End Rot Explained Simply
