Which Type Of Fertilizer Should I Use For Hydrangeas?

The color morphing of hydrangea flowers can be a surprise, especially for bigleaf hydrangeas, H. macrophylla, or H. serrata (mountain hydrangea). To ensure healthy hydrangeas that truly shine, it is crucial to fertilize properly. The best fertilizer for hydrangeas is a slow-release product that provides essential nutrients such as nitrogen, phosphorus, and potassium gradually over several months. It is also important to select a fertilizer specifically formulated for hydrangeas or flowering shrubs, ensuring it has the correct N-P-K ratio and nutrient. Some hydrangea fertilizers contain ingredients to adjust the soil pH, allowing you to achieve your desired flower color.

For blue blooms, use a fertilizer that contains sulfur or aluminum sulfate. Compost is a great way to slowly energize hydrangeas. Hydrangeas benefit from a 10-10-10 NPK fertilizer, while higher phosphorus fertilizers like 10-20-10 NPK are ideal. Organic, slow-release, all-purpose, balanced fertilizers also work well for hydrangeas, but they won’t boost the size and number of blooms like a rose fertilizer will.

The best fertilizer for hydrangeas is a granular (ie, not liquid) fertilizer formulated for woody plants. Rose food is ideal as is any granulated shrub fertilizer, either organic or a time release product. A good all-purpose 12-4-8 or 10-10-10 composition will provide all the fertilizing hydrangeas need. Either a chemical source or organic matter is recommended for hydrangeas.