What Causes Brown Spots on Hydrangea Flowers?

Summer is in full swing and your hydrangea blooms are bursting with color. Or are they? These beautiful flowering shrubs are low maintenance but sometimes they can cause gardeners some anguish. At the top of the list is anything that has to do with flowers that don’t look good, especially flowers that turn brown.

Hydrangeas can have a reputation of being high maintenance, and I think this is because of their beauty. What could be so easy about something so pretty? The truth is that they are easy to take care of as long as you do a few simple things.

If your hydrangea flowers are turning brown, there are a few different causes for this. Here are some of the most common reasons you might be having this problem, along with some tips on how to fix it!

With their large, showy blooms, hydrangeas are stars of the summer garden. Their big, colorful flower heads last for months and come in shades of pink, blue, purple, red, and white depending on the variety. But sometimes those flawless blooms can become marred by unsightly brown spots.

Brown spots on hydrangea flowers are usually a sign of disease While the plant as a whole is often not severely affected, the blemished blossoms become less attractive Knowing what causes the spots and how to treat them can help you keep your hydrangeas looking their best all season long.

Common Causes of Brown Spots on Hydrangea Flowers

Here are some of the most frequent causes of brown spotting and discoloration on hydrangea blooms:

Botrytis Blight – One of the most common diseases, botrytis blight thrives in cool, wet, humid weather. It produces tan lesions on the flowers that eventually turn brown. Entire flower heads can shrivel up and turn brown with this fungal infection.
Bacterial Blight – Angular spots that first appear water-soaked before turning brown are symptomatic of bacterial blight It spreads rapidly in warm, rainy weather
Anthracnose – This fungal disease causes brown-bordered lesions on petals. During wet weather, pink or orange spore masses form in the center of spots It can defoliate plants.

Leaf Spot – Leaf spot fungal diseases like Cercospora and Phyllosticta can move from the leaves to the flowers causing small, round brown spots.
Sunscald – Exposure to intense afternoon sun can burn the delicate petals, especially on white hydrangea varieties, resulting in dried out brown spots.
Frost Damage – Early fall frosts can crisp and brown the tender blooms of some hydrangea species. The damage starts on the tips of the petals.

Chemical Burn – Pesticides or fertilizers applied at the wrong time can sometimes chemically burn the flowers leading to brown blemishes.

How to Treat Brown Spots on Hydrangea Flowers

If your hydrangea blooms develop brown spots, take these actions to treat and prevent further damage:

Remove and destroy any severely affected flowers. Don’t compost them.
Improve air circulation and light penetration through pruning and spacing.
Water at the base of plants rather than overhead to keep leaves and flowers dry.

Apply fungicidal sprays as needed during wet weather if disease is severe.
Move plants out of hot afternoon sun or provide shade if sunscalded.
Cover plants to protect from frost in fall if necessary.

Apply chemicals according to directions to avoid burn.
Trim back plants in fall to remove dead wood and debris where diseases overwinter.

How to Prevent Brown Spots on Hydrangea Flowers

You can reduce the chances of your hydrangea blossoms developing ugly spots and blemishes by following these preventive measures:

Choose disease-resistant varieties like Endless Summer.
Space plants properly to allow air circulation.

Prune regularly to open up dense growth.
Water at the base early in the day.
Apply mulch to prevent soil splashing onto flowers.

Use drip irrigation rather than overhead sprinklers.
Pick off and discard any spotted flowers.
Avoid excessive nitrogen fertilization that promotes succulent growth vulnerable to diseases.

Apply fungicidal applications preventively when conditions favor disease.
situate plants where they will be shaded during the hottest part of the day.
Cover bushes with fabric when frost is predicted in fall.

Stick to recommended application rates and timing when using pesticides.

Are Brown Spots on Flowers Harmful to Hydrangeas?

While brown spots on the blooms are unsightly, they usually do not seriously harm the overall health of the plant. As long as the disease is confined to the flowers, the hydrangea will continue to bloom and thrive.

However, diseases like anthracnose and botrytis blight can spread to the leaves, stems, and buds if left untreated. This can weaken or even kill the plant over time. Catching the problem early when it is limited to the blossoms gives you the chance to stop it before it impacts the whole shrub.

Even if disease doesn’t spread, recurrent flower spotting year after year can reduce the vigor of the plant and number of blooms. It’s best to implement preventive care to stop spots from sullying your hydrangea flowers in the first place. But with proper treatment and care, your hydrangeas can continue flourishing despite occasional rounds of spotty blooms.

Check Your Water Schedule

Hydrangeas require about one inch of water per week to look and feel their best. They are best watered at the base of the plant. Too much moisture on the leaves can cause issues with fungal disease. Watering the foliage doesn’t do anything beneficial for the leaves. Aim for the roots and you will be in good shape.

Over-watering can cause smaller flowers to turn brown.

If you have been a bit too generous with your watering you may notice some effects of overwatering. Too much water can cause hydrangeas to have small blossoms, or none at all. If your flowers are already blooming you may notice the petals of the flowers turning brown.

If you want to know if you’ve been watering too much or too little, just look at the leaves. Over watered plants may have leaves that turn yellow and fall off the plant. You can also play around in the dirt and see how wet or dry it feels. It should feel moist, but not muddy.

The best way to resolve over watering is to just take a break from watering altogether. When your soil seems to have dried out a bit and you are ready to start watering again, make sure you water slowly.

You might also want to keep track of how much water your garden is getting with a rain gauge. If you are getting an inch or more of rain you may not need to water at all.

With insufficient watering, the leaves will begin to fade, and the flowers will turn brown.

If hydrangeas don’t get enough water, their leaves and flowers start to dry out. It’s not pretty. It is very common to see them in a mid day slump.

The leaves will droop towards the ground and the flowers will begin to droop and look sad. In the afternoon, when it’s hot, this usually happens. The flowers and leaves will grow back as soon as they get out of the sun.

But if you let this happen over and over, the symptoms won’t be as easy to fix, and you’ll see that the flowers start to turn brown from the tips down.

Supplemental water in the heat of the summer is often necessary. In the event that your plants aren’t getting an inch of water every week, you should water them more often. It is best to water slowly and deeply. Dumping a bunch of water onto a dried out plant won’t help much.

This means that the soil is usually dry, and even a heavy rainstorm won’t be able to wet it. Set the hose to a light stream and leave it there until you see that the soil is nice and wet.

Once your plants look like they’re getting better, you should probably water them once or twice a day during the hot months. I like to water my plants early in the morning and again in the evening if they need it. This seems to give them enough water to keep them from drooping in the middle of the day and also help them recover.

Large-leaved hydrangea prefers to grow in partial shade.

You shouldn’t have to worry about this if you have planted Hydrangea paniculata, also known as panicle hydrangea. They do well in full sun.

When you plant a bigleaf hydrangea or any other kind of hydrangea, the flowers may turn brown because they are getting too much sun. These types do best in partial sun which is about 4-6 hours of sun per day. If the sun comes up in the morning, it’s even better because they’ll be in the shade when it gets hot.

Moving your shade-loving variety to a spot that gets less sun could help with this problem. Plants should not be moved until fall or spring. Once they are moved, they should be kept well-watered.

You can always move the plants to a pot if you don’t have a free shady spot in your yard. Oftentimes containers offer flexibility to gardeners because you can move the pot around as needed. Purchasing a pot base with wheels can make this even easier.

If you have tons of full sun in your garden, panicles are the way to go. This type is larger and are very beautiful when planted alone or in a mass planting. There are also some compact varieties available that are equally as pretty.

Why Do The Flowers Turn Brown?

Their flowers may turn brown before frost, due to heat or insufficient watering.

Nothing lasts forever they say. This is true about the beautiful colors of our beloved hydrangea flowers. Every flower, no matter what color it is at first, will turn some shade of brown when it frosts.

Sometimes these flowers will brown prematurely due to growing conditions. This could be a result of a heat wave, inadequate watering, or poor plant placement.

Q&A – Why does my hydrangea have brown dark spots all over?

FAQ

How do you get rid of brown spots on hydrangeas?

The problem is caused by a fungus that spreads via spores in wet or humid conditions. To control leaf spot, avoid watering your hydrangeas from overhead, and again, remove and destroy diseased plant parts. If summer rains make the problem worse, try a fungicide such as Immunox (always follow label directions).

What to do when my hydrangea flowers turn brown?

Are the blooms on your hydrangea shrubs fading or turning brown? No need to worry – this is simply a sign that it’s time to remove the flowers, a process called deadheading.

What does overwatered hydrangea look like?

Wilted or drooping leaves – If you see heavy leaves that seem to hang that may even be mushy to the touch, you might have overwatered hydrangeas. Flowers that constantly wilt and/or fewer flowers – A lack of blooms or wilting blooms is usually a sign that something is amiss with your plant.

Why are my hydrangea leaves turning brown?

Here are some specifics: Insufficient Watering: The inadequacy of water can lead to the browning of leaf edges, eventually causing crispy spots. Too Much Sun: Hydrangeas exposed to excessive sunlight may exhibit signs of sunburn, exhibited by brown spots on the leaves.

Why are my hydrangea leaves turning white?

Hydrangeas are susceptible to leaf spot which can be caused by a number of different fungi. Leaf spot could present itself as light brown spots with a darker brown border. As the disease progresses the spots will grow, the leaves will turn yellow and eventually fall off. This fungus leaves a white powder on the surface of your leaves.

What causes yellow spots on hydrangea leaves?

Here’s what I found about some common diseases that could be causing these symptoms on hydrangea plants. Cercospora is a fungal disease that results in brown, circular spots with a purple halo on hydrangea leaves. I’ve observed that as the disease progresses, the spots may expand, leading to yellowing and dropping of leaves.

How do you prevent brown spots on hydrangea leaves?

Maintaining the health of hydrangea leaves and preventing brown spots involves consistent care with a focus on proper watering, soil management, and regular pruning. Hydrangeas thrive with consistent hydration, but it’s crucial to avoid overhead watering to minimize the risk of brown spots. I always use the following method: