Neptune’s Harvest Crab and Lobster Shell is a superior dry fertilizer for all your growing needs. It has an NPK of 5-3-0, but also contains Calcium (17%) and Magnesium (1%). This organic fertilizer is high in chitin and will promote the growth of beneficial organisms in the soil and help deter plant parasitic nematodes. The high calcium content of Neptune’s’ Harvest Crab and Lobster Shell reduces the effects of fungal diseases such as blossom end rot and helps plants develop healthy, strong cells. Works well with kelp meal fertilizers High calcium fertilizers are great for bulbs and flowers Can be worked into the soil before planting or used as a top dress Shop All Neptune’s Harvest Products here .