According to Karen Mitchell, Jefferson County Master Gardener, irrigating below the leaves and flowers at the base of the plant is best practice to avoid fungal-related issues and ensure the water goes directly to the root system.
Deeply water 3 times a week to encourage root growth. Bigleaf and smooth hydrangeas require more water, but all varieties benefit from consistent moisture. Use a soaker hose to water deeply and keep moisture off the flowers and leaves.
Deep weekly watering is usually enough (if you don't get enough rain). Although you may need to water more often in hot, dry weather. Water hydrangeas deeply and regularly in the first growing season to encourage an extensive root system.
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.
All you need to do is submerge hydrangeas bloom-down in a bowl of warm water for 30 minutes to an hour, taking care not to leave the arrangement submerged for too long. "Prolonged exposure of the petals in water can actually damage the flower," says Manhattan-based florist Rachel Cho of Rachel Cho Floral Design.
Yellow or Brown Leaves
When a hydrangea has been overwatered, one of the most obvious signs is yellow or brown mushy leaves. Touch your hydrangea's leaves just to make sure – dry leaves can be a sign of underwatering, so feeling them will help you tell the difference.
There's no way around it: Hydrangeas in pots will have to be watered more frequently than those in the ground. Because it's living in a smaller space, you can expect this space to dry out more quickly than the ground will. To keep your potted hydrangea happy, try watering it every other day in the summertime.
The goal is to have them last about two to three weeks! If they start to droop after a few days, cut the stem again and change the old water out to hot water once or twice a week. You can also mist the blooms daily – hydrangeas are one of the very few flowers that can actually drink water from their blooms!
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.
Roots need oxygen to thrive, and if they are sitting in water for too long, they may begin to rot or die. The best way to prevent root rot from forming is to plant your hydrangea in well-draining soil to reduce the chances of fungal development.
When a hydrangea is cut, displayed in a vase, and looking quite lifeless, turn the flower upside down and completely submerge its head into a bowl of water overnight. “Hydrangeas are one of the only flowers that actually absorb water through the petal,” the florist said in the video.
Most common hydrangeas prefer a partial sun location - ideally receiving sun in the morning hours and shade in the afternoon. The reblooming Endless Summer® Hydrangea series prefers part shade. These include BloomStruck®, Endless Summer®, Blushing Bride®, and Twist-n-Shout®.
First, add a 1/4 cup of sugar to the room temperature water in the vase. The sugar helps feed the stems and increases the life of the cut flowers.
Put hydrangea in very hot water – boiling temperature. Nearly all flowers like warm to very hot water. Never use cold water. The only exception to this is bulb flowers, like tulips.
Treating Slugs on Hydrangeas
You can spray the plants with soapy water. Use a teaspoon of dawn or joy dish soap with a quart of water in a spray bottle. Spray the leaves, branches and the ground beneath the plant.
Most hydrangeas prefer only morning sun. Yet one type of hydrangea can soak up the sun all day: the panicle hydrangea. While they can stand the sun, these do just fine in partial shade, too. Plus, panicle hydrangeas are the hardiest hydrangeas.
In warmer areas, many hydrangea types will suffer in the afternoon's scorching sun. The leaves and flower heads may burn, turning brown. If you notice this, that means your hydrangea is getting too much sun. Try moving it into filtered shade, or an area where it gets only a few hours of morning sun.
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.
Brown, tan, yellowish or black spots on hydrangea leaves may be anthracnose. You can also identify it by cankers that form on stems and branches. Anthracnose can be fatal to hydrangeas, so prune out dead or diseased plant parts and destroy them.
If the soil is wet, it's overwatered - if it's dry, it's underwatered. Browning edges: Another symptom that can go both ways. Determine which by feeling the leaf showing browning: if it feels crispy and light, it is underwatered. If it feels soft and limp, it is overwatered.
Removing spent flowers will ensure your hydrangeas produce healthier, more bountiful blooms later on.
Have you ever cut hydrangea blooms and put them right into a vase of water only to have them wilt within an hour or two? This seems to be caused by a sticky substance that clogs the stems, preventing moisture from reaching the blooms. This does not happen every time.