Some hydrangeas will change flowers based on soil pH such as Endless Summer Hydrangeas. A lower pH will grow blue flowers, a higher pH will grow pink flowers. Vanilla Strawberry Hydrangea isn’t one of those hydrangeas. Their flowers will change colors when the night temperatures cool in the fall. To grow more flowers, use a fertilizer with a higher middle number on the NPK ratio. Phosphorous helps grow flowers. Also, be certain you don’t accidentally prune off the flower buds. Here’s a video with tips on how and when to prune.
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