Water plants deeply prior to the heat event so that the root zone is well hydrated. Place mulch, such as bark, around plants to help keep in moisture. Avoid applying gravel or black-plastic mulches, which raise soil temperatures. Prior to planting, amend soil with organic matter.
4. All hydrangeas will turn brown if they wilt too many times in hot weather. Water these shrubs deeply every few days in the heat of the summer (note that hand watering isn't deep enough) and mulch around plants to hold moisture in the soil longer.
Panicle hydrangeas can handle hot sun
While they are drought tolerant and stand up to heat, I still like to provide shade during the hottest part of the day. And just because they are drought tolerant doesn't mean you should let them wilt. As with all hydrangeas, plants will thrive with regular irrigation.
Hydrangeas need more water than most garden plants and will begin to wilt quickly without it. To ensure that Hydrangeas thrive, water deeply two to three times a week in the summer. Be sure to water in the morning or evening so that water does not evaporate as quickly as it would during the heat of the day.
If your hydrangea foliage is also damaged, it may be sunburned (crispy or brown around edges). Depending on the amount of total damage, your plant will eventually recover from severe sunburn, but may not rebound from extreme drought.
Too much sun exposure can cause your hydrangea shrubs to burn on its leaves and blooms. Also, be sure to put your fingers in the soil to see if it needs watering. We do recommend a soak versus light watering each day, but you should be sure that the soil is always moist – not wet – by sticking your fingers in the dirt.
Bigleaf hydrangeas, also known as hydrangea macrophylla, vary especially with some of the newer cultivars being bred to better tolerate heat and sun, but most of these including the mopheads and lacecaps prefer some shade, especially during the afternoon.
"Hydrangeas can look stressed in extreme heat but will perk up when temperatures drop," says Clay. "If the plant is looking a bit sad even with cooler temperatures, it likely needs water."
Mature flowers with a slightly papery feel will hold up best. Immediately place the stems, cut at an angle, in a bucket of water. Arrange them right away, or store in a cool, dark place (such as a garage) for up to two days.
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.
Hydrangeas can be grown in full sun but too much direct sunlight, especially during the afternoon hours when the sun is most intense, can cause wilt. When exposed to excessive sun, the plant's internal temperature increases, which causes the leaves to transpire and leads to moisture loss in the cells.
Hydrangea blossoms are at their best when they are well watered and well fed. Mulch also provides an evaporation barrier. Keeping your soil moist in the heat of the summer, which is also the flowering season for hydrangeas, will help to maintain the healthiest version of your plant.
Stephen Sullivan, the editor at Plant Native, says: 'Among the different types of hydrangeas, the Oakleaf hydrangea (Hydrangea quercifolia) and the Panicle hydrangea (Hydrangea paniculata) tend to be more resilient in dry conditions compared to the Bigleaf hydrangea (Hydrangea macrophylla).
The hydrangea should be watered thoroughly at least 3 times a week. Always water the plant all the way around the container, not just in one place. Water should come out the bottom of the pot. Never let it sit in water which will cause the roots to rot away.
It's best to start adding coffee grounds to the soil months before the blooming season begins, ideally in the late fall. You can repeat the process with your typical fertilizing schedule.
The further north your garden is located, the more sunlight your hydrangeas need. An average rule of thumb is six hours of sunlight per day. However, hydrangeas growing in the south can perform on only three hours of sunlight.
"In this heat, hydrangeas—especially the blue/pink bigleaf or "French" hydrangeas—will transpire water vapor from their leaves faster than their roots can replace the water," says Doggett. "This causes the stems, leaves, and blooms to wilt or droop by late afternoon."
Typical symptoms include yellowing leaves, or irregular dry, brown blotches. Leaf tips and margins may turn brown, as well. Severely damaged leaves may drop from the plant. Leaf scorch results when the leaves lose water faster than it can be supplied by the roots, so wilting may occur before scorch is noticed.
Appearance. The Endless Summer Hydrangea is a shrub, growing in a rounded shape. Its dark green leaves range from 4-8 inches long, and its stunning blooms are showy mopheads nearly 8-10 inches in diameter.
Yes, you can use many types of all-purpose balanced Miracle-Gro on Endless Summer hydrangeas.
"Bigleaf hydrangeas, such as endless summer, should be deadheaded when the first set of flowers sprout from last year's growth in the spring," says Meyers. This eliminates the faded flowers before the next flush appears.