Although bone meal is sometimes added to the soil around established shrubs, it has been traditionally added to the soil as an organic amendment before planting bulbs of flowers that bloom the following spring. Bone meal is 28 percent phosphorus by weight. Unless
Although bone meal is sometimes added to the soil around established shrubs, it has been traditionally added to the soil as an organic amendment before planting bulbs of flowers that bloom the following spring. Bone meal is 28 percent phosphorus by weight. Unless your soil truly needs phosphorus or you’re an organic gardener, weigh the benefits and drawbacks carefully before using bone meal.
Bone Meal Basics
Bone meal doesn't dissolve in water, but rather it releases phosphorus slowly as it decays. Phosphorus doesn’t leach from soil easily, so you may not need to add it. While phosphorus is needed for plant growth and is one of three main ingredients included in fertilizer formulations, high concentrations can cause problems. Root tips exude acids that allow the penetration of useful fungi. These fungi help plants take in nutrients and water. When phosphorus levels in the soil are too high, the fungi spores go dormant. To compensate, plants grow more roots at the expense of the rest of the plant. Transplanted seedlings may suffer shock from lack of fungi in the soil. The best way to know whether you need to add phosphorus is to test your soil. A home test kit gives a basic idea of the phosphorous levels.
Flowers that grow from bulbs contain all the nutrients they need for the first year of growth, notes the Netherlands Flower Bulb Information Center. If you believe your soil lacks phosphorus and you plant a bulb in the fall, incorporate 1/3 teaspoon of bone meal to the soil three weeks before you plant it. Work the bone meal deep enough so the roots of the bulb have to grow through it, in the process gleaning all the phosphorus the plant needs. For a larger area of soil, work 3 pounds of bone meal into the top 3 inches of each 100 square feet.
If you leave the bulbs in the ground to bloom again, then you should fortify the soil with a balanced bulb food after the flowers have faded in spring. This is when bulbs store food for flowering the next year. Chicago Botanic Garden recommends a 10-10-10 or 10-15-10 slow-release, balanced fertilizer. Apply the fertilizer at a rate of 2 cups for each 100 square feet to the top of the soil then lightly cultivate the soil to work the fertilizer in then water it well. If you’re an organic gardener, add well-rotted compost or cow manure in the fall of their second year of growth. Work a 1- to 2-inch layer of compost into the top 6 to 8 inches of soil.
The nutrient value of commercially prepared bone meal is less than traditional bone meal because it is steamed before grinding to remove bits of bone marrow and scraps of meat. A drawbac