Crab & Lobster Shell Fertilizer 5-3-0 (4 lb)

Neptune's Harvest Crab & Lobster Shell Fertilizer (5-3-0) is a dry organic plant food made from crab and lobster shells, naturally rich in calcium (17%) and magnesium (1%). Calcium strengthens cell walls and supports root development, while magnesium fuels photosynthesis, making this a sustainable choice that recycles seafood-industry shells.

At a glance

• Analysis: 5-3-0 NPK
• Calcium: 17%
• Magnesium: 1%
• Size: 4 lb
• Type: Dry organic fertilizer from crab and lobster shells

Best for

• Strengthening plants and root systems with calcium
• Supporting bulbs and flowering plants
• Pairing with kelp meal for fuller nutrition
• Organic and sustainable gardening programs
• Building healthier, more resilient soil

How to use

Work the fertilizer into the soil around plants, following the manufacturer's recommended application rates to avoid nutrient imbalances. For a broader nutrient range, use it together with kelp meal, which adds nitrogen, potassium, and micronutrients. Water in after applying.

About Grow Organic

Grow Organic supplies natural amendments, seeds, and tools for healthy soil and productive gardens, helping growers build fertility with earth-friendly methods.

Sold by Grow Organic, based in Grass Valley, California.