Oyster Shell Flour
Source of calcium.
Recommended for tomatoes and all vegetables. May be used with flowering plants, trees, ornamentals and shrubs.
May be used to raise soil pH.
available sizes: 5 lbs, 25 lbs
density: 0.70 lbs per cup
release time: 1-4 months
Derived from crushed oyster shell
Oyster Shell Flour may be used with all plants.
Application Rates – always mix into soil. Rate will vary significantly depending on if and what pH adjustment is desired (these are fairly conservative)
Roses, flowers, large plants and shrubs: use 1/2 cup per plant early in season (or at planting), 1/2 cup mid-season.
Vegetable gardens/beds: 2-3 lbs per 100 square feet, per month.
Containers: 1-2 tablespoon per gallon of soil, twice per season.
See ‘Plant feeding requirements‘ if you are using oyster shell in combination with other products or for more information.
See ‘Feeding with organics‘ for general information on using organic nutrients.