When you deadhead hydrangeas, you aren't harming the plants at all. Removing the spent blooms triggers flowering shrubs to stop producing seeds and instead put their energy toward root and foliage development. This makes plants stronger and healthier, so by deadheading, you'll be doing your hydrangeas a favor.
Removing spent flowers will ensure your hydrangeas produce healthier, more bountiful blooms later on.
The best time to deadhead is when the first set of blooms on your hydrangeas begin to turn brown and dry. Cut the stem below the flower head and just above the first set of leaves. For reblooming types, you can deadhead again when this second set begins to fade, but only through mid-August or so.
"If you want a longer stem, you can make a deeper cut as long as it is done before July or August when the plant begins forming buds for next year's flowers." For smooth hydrangeas, she suggests removing the faded flowers as soon as they fade to green to ensure a second flush of smaller flowers in the fall.
'To deadhead hydrangeas, take each flower that's on its way out and follow the stem down to the next set of large leaves,' instructs Anna. You should see tiny buds in the crease between the stem and the leaf, she says.
Without going through the deadheading process, hydrangeas will not produce as many flowers and the few produced may not grow as big to their full potential.
Keep good air space between the plants; don't crowd them together or against other plants. Don't give bigleaf hydrangeas too much love; if they're too comfortable (water, fertilizer, etc.), they may devote all their foliage to leaves instead of blooms.
With insufficient watering, the leaves will begin to fade, and the flowers will turn brown. When hydrangeas do not get enough water they begin to get crispy; their leaves, their flowers… it's not pretty. It is very common to see them in a mid day slump.
Wait to prune your bigleaf hydrangeas until new growth appears in the spring. Make pruning cuts one quarter inch above the first set of live buds. Hint: stems with live buds will be green on the inside, while dead stems will be brown. Entirely dead stems should be cut flush to the base.
According to Hirvela, your hydrangea is done blooming when the color of the flowers has faded in a non-appealing way. "There are a few varieties that will continue to push out new buds through late summer and autumn," she says.
Remove dead or crossing stems. Cut these stems close to the ground. Remember buds for blooms are produced on old wood and the more old wood you remove the less floral display in the spring and summer. To rejuvenate the hydrangea, remove up to 1/3 of the older living stems down to the ground each summer.
Now, you can choose a variety of hydrangeas that bloom all summer long. You can even prune these at any time. Reblooming hydrangeas flower on both new and old growth, meaning you can enjoy flowers from June until the first frost. They'll continue to bloom long after other flowering shrubs and perennials have stopped.
Know when they're beyond repair.
If you catch and treat your hydrangeas when their blooms first start turning brown, Myers says there's a good chance you'll be able to turn them around (as long as it's not due to weather damage). "However, once they turn fully brown, there's not much you can do," she says.
Hydrangea Care Tips
Water at a rate of 1 inch per week throughout the growing season. Deeply water 3 times a week to encourage root growth. Bigleaf and smooth hydrangeas require more water, but all varieties benefit from consistent moisture.
Some gardeners report success in turning their hydrangeas blue by applying coffee grounds to the soil. The coffee grounds make the soil more acidic, allowing the hydrangea to more easily absorb aluminum. In addition, fruit peels, lawn clippings, peat moss and pine needles, are thought to have a similar effect.
But hydrangeas are among the few plants that can draw moisture in through their florets, so it's possible to perk up wilted blooms by completely submerging them in water and letting them sit for a few hours to rehydrate.
To reduce the size of a hydrangea that blooms on new wood, cut off about one-third of each stem in late fall or early spring before it begins to leaf out. If your hydrangea blooms on old wood, prune right after it has bloomed when the flowers are fading.
Wrap with winter protection.
During the winter, make a DIY A-frame wire cage out of burlap and chicken wire to protect your hydrangea plant. This cage will protect it from winter winds, heavy snowfall, and cold temperatures.