If your hydrangea is showing signs of stress because it's recently planted in soil amended with manure then transplant the hydrangea to an area with soil and compost and it should recover. Cut back any brown leaves or flowers and scale back the use of fertilizer.
Both over and under-watering your hydrangeas can cause them to weaken and brown, so Myers says it's crucial be precise about irrigation. "Water established plants thoroughly but less frequently to encourage deep roots that are more drought tolerant," she says.
If your hydrangeas do get infected, you have several options, including compost tea, hydrogen peroxide, garlic oil, or liquid kelp. You can also apply the fungicides chlorothalonil or thiophanate-methyl.
If the leaves on your hydrangea have started turning brown and crispy, there's several reasons why this can happen. The good news is that it can be fixed in most circumstances, and if you catch it early enough, it likely won't cause your plant to die.
However, stop deadheading hydrangea shrubs in mid to late fall, leaving any spent blooms in place. This not only provides winter interest, but also ensures you don't remove the buds that will become flowers next spring.
Small, round, brown or purplish spots on hydrangea leaves are common. Often, affected leaves turn yellowish green and fall off, although the plant usually survives. The problem is caused by a fungus that spreads via spores in wet or humid conditions.
Orange spots that form on the bottom or the underside of the leaves are hydrangea rust. The top of the leaf will turn yellow and the leaf will eventually die. This rust is another fungal disease that hydrangeas can contract.
You can use vinegar to lower the pH of your soil, but be aware that in order to achieve blue blooms, you will need both an acidic environment and aluminum ions. The acidic environment will also need to be a sustained over a period of time, which could be hard if rainwater is washing the vinegar away.
Here's what to look for: Leaf discoloration: hydrangea laves typically become yellow and brown when overwatered. However, the discoloration can also be a sign of underwatering. Usually, when the plant is overwatered, the browning occurs on the edges of the leaves.
The reason for hydrangeas wilting and dying is because there is not enough moisture around the roots due to lack of watering or rainfall, the soil drains too quickly, too much sun or excessive wind saps moisture from the leaves. Hydrangea flowers can droop due to excess fertilizer.
Shallow or inconsistent watering.
If a hydrangea is being watered every other day for twenty or thirty minutes (sadly, standard automatic irrigation settings) the plant is likely to wilt in hot weather. Once the flowers wilt a few times they will turn brown.
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.
This common household item is surprisingly effective at helping perk up plants and brighten blooms. For hydrangeas specifically, adding baking soda helps the plant retain more moisture in the roots. When this happens, the result is bigger blooms with more vibrant colors that last longer than they would otherwise.
If your Hydrangea flowers dry out they will turn brown. Similarly, if the plants are growing in full or afternoon sun they will fade rapidly. Be sure to keep your shrubs deeply watered during hot weather. A layer of mulch around the plants will help keep the soil moist.
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.
To apply these natural remedies, use as directed on the bottle. For hydrogen peroxide, mix 1 ounce with 8 ounces of water in a spray bottle and spray on the leaves. We also recommend removing all diseased and dead leaves off of the plants, to help prevent the spread of the leaf spot.
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.
Symptoms of Phytophthora root rot are the sudden wilting and yellowing of the foliage. Infected hydrangea roots may exhibit brown discoloration and this discoloration can be seen on crown at the soil line and stem above the soil line as well.
Too Much Sun/Heat: This problem often occurs in conjunction with Hydrangeas that don't get enough water. These shrubs do best in the morning sun, and too much direct sunlight (especially in the south, where the sun is more intense) will cause the leaves to get burned, turn brown, dry out, and curl up.
Prune back stems to just above a fat bud — called a heading cut — in fall, late winter or spring. These plants have conical-shaped flower heads. I recommend leaving the dry, tan flower heads on the plant to provide some winter interest in your landscape, so I wait to prune these until late winter or spring.
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.
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.