So, you have a new hydrangea this year. Excellent! Hydrangea are a huge and diverse group of shrubs with large showy clusters of tiny flowers. Will it bloom again next year? Yes, it will bloom next year if it is the correct kind for our area and if you care for it properly.
“Why doesn’t my hydrangea bloom?” is a common question with a complex answer. “Did you receive the hydrangea for Easter or Mother’s Day?” “Did it have pretty foil or plastic around the pot?” If so, your plant may be a “florist’s” or “gift” hydrangea. It is simply not winter hardy in our area. Mother Nature freezes the flower buds and/or the stems each year, destroying the future flowers. The hydrangea roots may be hardy, but the top of the plant is not. Usually, these plants are a big-leaf hydrangea (Hydrangea macrophylla).
Most varieties bloom on “old wood,” i.e., wood that grew and produced flower buds during the previous year. Therefore, early or late freezes or bitter winters may damage the flower buds. The other reason that these hydrangeas don’t bloom is pruning at the wrong time. If you cut back a hydrangea between the autumn and spring and it blooms on old wood, you have trimmed off all the future flowers.
Did the hydrangea previously bloom, but not recently? Another problem may be that the area is too shady. Have trees grown to shade the hydrangea? Most hydrangeas require partial sun or partial shade to do well. Full morning sun with dappled shade in the afternoon is ideal. Remember that nearby trees also absorb water from the soil and that hydrangeas do best in moist, well-drained, but not wet soil. Those big, soft leaves lose a lot of water by transpiration. High nitrogen fertilizer applied to lawns could be stimulating leafy growth rather than flower buds.
Look for a newer variety of Hydrangea macrophylla that blooms on both old and new wood. Read the plant tag and ask for help at a nursery. Try the “Endless Summer” or “Let’s Dance” collection of re-blooming hydrangeas. You get early bloom on old wood and later bloom on new wood (current season’s growth).
A bonus with the Endless Summer series is that you can choose the color of the flower by changing the soil pH. To produce blue flowers, the plant needs a soil with an acid pH to allow aluminum uptake. Apply a soil acidifier, aluminum sulfate, only one tablespoon per one gallon of water, to the soil each month of the growing season.
Take care to water well before treating, as this chemical can burn the roots. Consider using slow release, organic soil acidifiers that are gentler on the plants. Avoid fertilizer with high phosphorous levels. To encourage pink flowers, add lime and fertilizer with high levels of phosphorous to prevent the aluminum from entering the plant’s system. It may take more than a year to see a change in color. Be aware that lime may leach from house foundations and sidewalks. In these locations, blue flowers may be difficult or impossible.
How about taking the easy way? Plant a native, like Hydrangea arborescens. “Hills of Snow” or “Annabelle” are hardy here, produce beautiful white flowers that green with maturity and can be cut back, if desired, anytime from autumn to spring. They bloom on “new wood” so harsh winters are never an issue.
Another great native option is Hydrangea quercifolia, the oakleaf hydrangea, with four seasons of interest — huge white flowers that mature to shades of pink; gorgeous red leaves in the autumn; an open shape with brown exfoliating bark during the winter; and green, oak leaf-shaped foliage in the spring.
Perhaps you don’t have space for a bushy hydrangea. Try a tree form of Hydrangea paniculata “Grandiflora” or “PeeGee.” They bloom on new wood so one can trim off the new growth to the standard (trunk) each year, if desired. The huge flowers mature to pink and are easy to dry for winter bouquets.
Did you know that there is a climbing hydrangea? Hydrangea anomala dislikes sun and has holdfasts designed to cling. Just right to brighten a shady area by climbing a sturdy tree trunk.
There is one more thing to consider about non-blooming hydrangeas. Decide to embrace foliage. Just love the plant for what it is — a beautiful green mound.