For pink blooms: Add dolomitic lime to soil several times a year to raise pH (no higher than 6.2). Types of Hydrangeas. Mophead Hydrangea (Hydrangea macrophylla) Most problems are issues of watering, sunlight, and soil quality. When this comes in an easy to use packaged fertilizer, you can be sure that it will be an excellent choice for your hydrangeas. Hydrangeas are beautiful when they bloom in spring and summer. When I did a lot of landscaping as a teenager and in my early 20s, I was using bone meal for almost all of my plantings. Hydrangea flowers can be finicky, but taking care of your plant's needs increases your chances of getting to experience an amazing bloom. Burpee Organic Bone Meal Fertilizer; Bone meal contains vital ingredients such as calcium, phosphorus, and organic nitrogen. Using bone meal for plants has been passed down for generations.. It’s made from ground up animal bones and comes in a granular or powder form. It's an old gardening adage: toss a cup of bone meal into the planting hole for a rose bush to help it … These enhance the growth of your plants and encourage root strength. It also boosts the growth of alliums such as garlic, leeks , and onions. Fertilizing Hydrangeas Organically. Excellent results have been reported by visitors to this site after using composted manure. So it is a natural fertilizer for Hydrangeas. bags and directions say to use 1 teaspoon mixed into the dirt for bulbs. I buy mine in 4.5 lb. Commercial manure or compost can be applied yearly around the base of the hydrangea. These ingredients are derived from natural materials including Hydrolyzed Feather Meal, Pasteurized, Poultry Manure, Bone Meal, Alfalfa Meal, Greensand, Humates, Sulfate of Potash, Sulfate of Potash Magnesia, and Elemental Sulfur. For an organic approach, many gardeners use commercial manure on the soil around hydrangeas. Organic bone meal is often used for establishing lawns since it helps young plants mature quickly. Bone meal is an exceptional organic fertilizer to add for flowering plants like roses and amaryllis. After stating this with much certainty, I hasten to add that it is virtually impossible to turn a hydrangea blue for any length of time if it is planted in soil with no aluminum and that is highly alkaline (chalky). Use low-phosphorus, high-potassium fertilizers; avoid bone meal and superphosphate. How to Apply Bone Meal to Established Roses. However, sometimes they don’t bloom the way you want them to. Bone meal replaces depleted phosphorus and will get the plants off to a good start for summer growth. Use high-phosphorus fertilizers (similar to 25-10-10; phosphorus is the middle number). For shrubs, such as the hydrangea, apply 1 to 2 pounds (2.25 cups of bone meal equals 1 pound). Superphosphates and bone meal should be avoided when trying to produce blue.