Crab/Lobster shell chunks — Organic Crab Shell (5-3-0) a dry, nutrient-rich soil amendment that feeds plants while improving soil structure.

Derived from natural crab shells, this amendment delivers essential nutrients and soil-building benefits. It supplies Calcium (17%) and Magnesium (1%), with an N-P-K of 5-3-0, helping to fortify root systems, improve soil moisture retention, and contribute organic matter over time. Its chitin-rich composition supports soil biology and creates a more resilient growing environment for a wide range of plants.

• N-P-K 5-3-0 with Calcium 17% and Magnesium 1% to support healthy growth and stronger cell walls.
• Soil health & root development: moisture retention, increased organic matter, and a deeper, more robust root system that helps plants access nutrients.
• Biological benefits: high chitin levels promote chitin-eating bacteria in the soil, enhancing microbial activity and natural pest suppression.
• Pest and weed management: helps deter ants, grubs, fungus, and root nematodes (as they rely on chitin-based structures); can help deter slugs and snails and contribute to weed suppression around plants.
• Application flexibility: work into the soil before planting or top-dress existing beds; suitable for lawns when broadcast with a spreader.
• Versatility: effective on lawns and all types of garden plants, including containers and raised beds.
• Brand trust: from The Soil Makers, backed by a science-forward approach to soil amendments and proven performance in lawn and garden applications.

How to use

Work Crab/Lobster shell chunks into the soil prior to planting to improve root anchorage and nutrient access, or top-dress beds and lawns to gradually enrich the soil over time. For lawns, apply with a broadcast spreader and water in to help incorporation. Regular, seasonal applications can support long-term soil health and plant vigor.

Ideal use cases

Perfect for home gardeners and lawn enthusiasts looking for a natural, organics-based fertilizer alternative that also enriches soil structure. Use in vegetable and flower beds, around perennials, and as part of an ongoing lawn care program to promote healthier turf and deeper roots.

Category context: Home & Garden > Lawn & Garden > Gardening > Fertilizers. The Soil Makers brings a science-based, soil-first approach to these soil amendments, designed to support robust plant growth and sustainable soil health without synthetic inputs.

Organic Crab Shell (5-3-0) is an excellent dry organic source of nutrients, including Calcium (17%) and Magnesium (1%). It retains moisture in the soil and builds the organic matter. It also gives the roots something to grab onto and wrap around, for a food source, creating a deeper root system. Crab Shell is high in Chitin (Kite-en), which promotes the growth of Chitin eating bacteria in the soil. It will help eliminate Ants, Grubs, Fungus and Root Nematodes, because they are all Chitin based in structure. Put around plants, Crab Shell will keep Slugs and snails off. It also helps choke out weeds and keep moles, voles, mice, etc… from digging up bulbs and root vegetables.

Crab Shell should be worked in the soil before planting, or top dressed. It can be applied to lawns with a broadcast spreader. It shows amazing results on lawns and all plants.