Do you know if you have lace cap or mophead hydrageas? The lace cap produce “flowers” that consist of teeny, tiny flowers surrounded (more or less) by substantially larger, usually four-petal flowers. Mopheads have the large balls of same-size flowers. If that’s not what you’re dealing with, we can only suggest this: It could be as simple as too much shade or too much sun. It could be too much fertilizer, esp high nitrogen fertilizer, which will result in beautiful foliage but few if any flowers. It could be too much moisture—or too little moisture. And, how is the pH of the soil?? Have they got enough compost? There may not be a good, solid explanation, but moving them to a different “environment” will at least give you a point of comparison. Also, the blooming of hydrangeas is affected by how they have been pruned, which depends on the type of hydrangea. Some bloom on second-year wood, others on the current year’s growth. Not knowing the type you have or how it has been pruned, I can’t say for sure why it isn’t blooming.
Do you know if you have lace cap or mophead hydrageas? The lace cap produce “flowers” that consist of teeny, tiny flowers surrounded (more or less) by substantially larger, usually four-petal flowers. Mopheads have the large balls of same-size flowers. If that’s not what you’re dealing with, we can only suggest this: It could be as simple as too much shade or too much sun. It could be too much fertilizer, esp high nitrogen fertilizer, which will result in beautiful foliage but few if any flowers. It could be too much moisture—or too little moisture. And, how is the pH of the soil?? Have they got enough compost? There may not be a good, solid explanation, but moving them to a different “environment” will at least give you a point of comparison. Also, the blooming of hydrangeas is affected by how they have been pruned, which depends on the type of hydrangea. Some bloom on second-year wood, others on the current year’s growth. Not knowing the type you have or how it has been pruned, I can’t say for sure why it isn’t blooming.