Hydrangeas like morning sun, but do not do well if they're in direct, hot afternoon sun. Partial shade in the later parts of the day is ideal for these beauties.
Sun helps many varieties bloom, but full sun is rarely required. Bigleaf hydrangeas, which are the variety most people think of when they think of these popular shrubs, can take full sun in cooler areas (zones 4 to 6). But in warmer areas (zones 7 to 9), they do best with morning sun and afternoon shade.
Hydrangea Light Requirements
Hydrangeas also prefer morning light, which is typically gentler and less hot than afternoon light. While some hydrangeas will tolerate full sun (six hours or more of direct light), they'll likley perform better with a bit of shade.
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 grow best with morning sun and afternoon shade. Hardy to zone 5, they require a well-drained soil and plenty of water. Avoid hot, exposed sites.
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.
The combination of too much sun and not enough water is a common cause of hydrangea droop, making it a great place to start when your plants are feeling unwell. Check the moisture level of your hydrangea at a point 1 to 2 inches (2.5-5 cm.) below the surface of the soil with your finger.
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.
To help Hydrangeas thrive, give plants a deep soak 1-3 times a week rather than giving them little sips of water daily. Hydrangeas do not tolerate overwatering or drought well. Their leaves wilt in the heat of midday, making it difficult to tell by appearance whether they need additional water or not.
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.
Foremost, plant the Panicle Hydrangea variety because this variety, especially the Peegee and Limelight types, tolerates the most sun- and even does well in direct afternoon sunlight. They have a higher sun requirement than the other varieties of Hydrangea, needing at least six hours of sunlight a day.
Endless Summer hydrangeas should be planted in a place that receives morning sun and dappled afternoon shade. "The amount of sun they can tolerate depends on the zone," says Mcenaney. "Endless Summer hydrangeas that are planted in zone 4 can tolerate more afternoon sun than those planted in zone 9."
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.
Hydrangea Heat Stress
Heat and drought stress can cause the stomata of your hydrangea plant to remain open as they try to absorb water vapor from the environment that they are in. Unfortunately, this causes water to be lost more than it is gained which over time translates into wilting.
However, if they aren't getting enough sun, they don't flower as much and their stems tend to be weaker and floppier. Don't let a little shade crush your hydrangea-garden dreams.
Many people think that you need a shady garden in order to grow hydrangeas. While that is true for some varieties, some hydrangeas thrive in sunny spots and even need full sun to develop into the fullest plants and the brightest blooms.
Water your hydrangeas in the morning before the heat of the sun is strong enough to quickly evaporate soil moisture. Try to avoid watering at night, which can encourage mold and mildew as the moisture sits through the cool night. Water your hydrangeas through the growing season as well as in late fall.
For hydrangeas planted in ground.
For optimal growth, bloom production, and quality, fertilize three times: In early spring when plants are just leafing out. In early May to boost their flower production for summer. In late June/early July to help your plants finish the summer strong.
Removing spent flowers will ensure your hydrangeas produce healthier, more bountiful blooms later on.
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.
Inadequate or Too Much Sunlight
To bloom, most hydrangeas require at least three to four hours of direct sunlight per day, ideally in the early morning or dappled sunlight in the afternoon. Locations with full afternoon sun are usually too intense. Both too little and too much sunlight can affect blooming.
Place the hydrangeas on the cutting board and use the sharp knife to cut the end of the hydrangea at a 45 degree angle. Then cut a small slit vertically up the middle of the newly trimmed stem. Place the hydrangea(s) in the vase filled with hot water. Let sit for a minimum of one hour and voila!
Wilting or mushy leaves: overwatered hydrangea leaves are heavy and drooping. They may be mushy or pulpy to the touch because their cells are flooded. Underwatered plants, on the other hand, will have dry and crispy leaves.
When you are arranging your hydrangeas re-cut the stem about an inch above the previous cut and immediately stick the bottom ½" of the stem in the alum to coat it, then arrange as usual. It's easy and works! No more wilted hydrangea blooms!