My hydrangeas are supposed to bloom all summer. The plants are healthy and growing so large they are taking over my garden. Problem is — no blooms. I have tried every method that has been suggested to me in regard to “cutting back” — time of year, length, etc. — without success. They are my favorite flowers. Please help!
The Gardener’s Answer
When Hydrangeas don’t produce flowers, it’s typically caused by improper pruning, too much or too little nutrients and/or inadequate growing conditions. Too much nitrogen can encourage leafy growth, but inhibit flowers from forming. Are your shrubs growing in a good amount of sun or do they receive mostly shade?
It is also possible that you purchased a floral type. This means that the plant itself is winter hardy, but the flower buds are not. Do you know what kind of Hydrangea you are growing? Different species have different pruning requirements. Pruning at the wrong time can result in lack of blooms. Panicle and arborescens (smooth) hydrangeas bloom on new wood, or current season’s growth. They should be pruned while the plants are dormant, before the new growth begins in the spring. Macrophylla (bigleaf) and oakleaf hydrangea bloom on old wood, or last season’s growth. These do not require annual pruning except to shape and remove dead wood. The best time to prune these is after they have finished blooming in the fall.
The overall health of your shrubs sounds good, but without the blooms they are not as pretty as they can be. Hopefully this gives you some insight.
If you have not had your soil tested recently, it would be a good idea. This can be done through your County Cooperative Extension Service.