Why Do My Hydrangea Leaves Have Brown Spots

Brown spots on leaves in a home landscape are typically brought on by a fungus or bacteria. Most of the time, the fungus or bacteria does not endanger the plant’s existence, but the blotches can be unsightly. These patches typically appear once a year in the late summer or early fall. The spots from the previous year do not interfere with the plant’s ability to blossom the next spring when the leaves reappear unharmed.

Fungal Leaf Spots on Hydrangea Leaves

Cercospora leaf spot and anthracnose are two different fungal diseases that can affect hydrangeas. 1a. Cercospora Leaf Spot, also called Cercospora Hydrangea, is characterized by spots at the base of the plant that are often brown or purple in color. The dots are tiny, with an average dimension of 1/8 to 1/4 inches. On the hydrangea macrophylla, spots can have tan or gray centers and border halos that are brown or purple. The leaf may get discolored and then fall off if it is diseased. Additionally, sometimes the entire hydrangea leaf can turn purple.

1b. The fungus Colletotrichum gloeosporioides is responsible for anthracnose. Large brown dots with cores that are lighter brown or tan result from this. The spots may also show up on the blossoms, which is a clue that the spots are anthracnose, a form of leaf spot.

How can brown stains on hydrangeas be treated?

On hydrangea leaves, small, rounded, brown or purple dots are typical. The damaged plant normally survives, although the diseased leaves frequently turn yellowish green and fall off. A fungus responsible for the issue spreads by spores in moist or humid environments. Avoid watering your hydrangeas from above to control leaf spot, and once again, remove and remove unhealthy plant portions. If summer rains exacerbate the issue, consider a fungicide like Immunox (always follow label directions).

How are brown leaf spots handled?

Are the plant leaves on your houseplants displaying brown spots? Black and brown stains on plant leaves and stems that have been sopped in water are frequently an indication of a bacterial or fungal disease. Change the watering schedule and avoid letting plants sit in water that is too much. That alone can frequently halt the spread of the illness. Any soft, discolored stems or leaves should be cut off and thrown away. Repot the plant in fresh potting soil in a container that is a little bigger than the remaining roots, trimming off any decaying roots.

Why do the leaves of hydrangeas get brown spots?

Most members of this plant family, including hydrangeas, are susceptible to the fungus Cercospora, which causes leaf spotting. From July to fall, it is typical. The fungus lives in the soil and is transferred to the plant by rain or overhead irrigation. Usually, plants become infected a month or two before leaf spots show up.

Do I need to remove the Brown hydrangea leaves?

If newly emerging hydrangea leaves or flower buds are exposed to a late-spring frost or chilly winds, they will turn brown. A unexpected cold spell can harm the newly emerging buds and leaves, which are exceptionally delicate and susceptible to injury. This can cause the buds to turn brown and wither away.

Naturally, hydrangeas grow in protected regions under trees that block chilly winds and produce a more stable microclimate that allows the young flowers to open up without facing a serious risk of frost.

Hydrangeas’ newly formed buds and leaves can become mushy and their leaves can turn brown when they sustain frost damage.

Since it is more exposed to the environment, the outermost growth is typically the one that suffers from the worst damage.

Sadly, the harmed flower buds are therefore unable to bloom, and the freshly growing growth is probably not going to recover.

Frost damage to hydrangea flower buds and foliage is more common in exposed areas, so plant or move your hydrangea to a more protected area of the garden, close to your house, or close to some other plants and hedges.

Particularly hedgerows are great wind breakers since they shield your hydrangea from the elements and might lessen the effects of frost.

There isn’t much you can do to save flower buds or younger leaves after they turn brown. As a result, prune back to healthy growth any growth that has been harmed by the frost.

In contrast to the flower buds on the plant’s outermost part, which are naturally less protected, hydrangeas frequently have growing flower buds farther down each branch. These flower buds typically survive a frost.

This means your hydrangea can still flower, but it may be much later and with fewer flowers developing, so with some patience there should still be some excellent blooms on display in the Summer.

How frequently should hydrangeas be watered?

Although the hydrangea’s leaves and flowers seem delicate, little careful care is actually needed for them. Everything you need to know about caring for hydrangeas is provided in these recommendations.

  • Over the course of the growing season, water at a rate of 1 inch per week. To promote root growth, deeply water three times each week. All varieties of hydrangeas benefit from constant moisture, but bigleaf and smooth hydrangeas need more water. To water thoroughly while keeping moisture off the flowers and leaves, use a soaker hose. Hydrangeas won’t wilt as much if they are watered early in the day on hot days.
  • To keep the soil around your hydrangeas cool and moist, add mulch. Over time, an organic mulch decomposes, supplying nutrients and enhancing soil texture.
  • Apply fertilizer according to the type of hydrangeas you have. Every variety has varied requirements and will profit from applying fertilizer at various times. A soil test is the most effective tool for determining your fertility requirements.
  • In March, May, and June, bigleaf hydrangeas require numerous mild fertilizer applications.
  • Two applications in April and June work best for oakleaf and panicle hydrangeas.
  • The only time smooth hydrangea plants require fertilizing is in the late winter.
  • By selecting cultivars with resistant characteristics, you can avoid pests and diseases. Hydrangeas can have leaf spots, bight, wilt, and powdery mildew. Although they are uncommon on hydrangeas, pests might arise when the plants are under stress. Aphids, leaf tiers, and red spider mites are examples of potential pests. Your best line of defense is to properly care for hydrangeas.

How can fungus on hydrangea leaves be treated?

Unfortunately, there are still more bacterial, viral, fungal, and even fungal illnesses that can harm the longevity, health, and look of your hydrangea. Let’s look at a couple of them.

Botrytis Blight Fungus (Botrytis cinerea)

How to recognize it: Botrytis Blight kills flower buds before they bloom by attacking them. The fungal infection can spread to the leaves below when the contaminated flower parts fall onto them. Typically, water-soaked patches on the blossoms are the first indication of this fungus. Then, lesions that appear reddish or brown.

How to treat or avoid it: Since Botrytis Blight prefers cool, moist environments, try your best to maintain low humidity levels, maintain excellent ventilation around them, and appropriately spacing your hydrangeas. Watering earlier in the day and focusing on the root rather than the flowers and leaves will also be beneficial. Make sure your pruning shears have been bleach-treated before using them to stop the spread of any existing diseases. Additionally, be sure to pick up any fallen, damaged, or dead flowers and foliage. Fungicides should be used to treat the fungus if it persists.

Anthracnose Fungus (Colletotrichum gloeosporioides)

How it occurs: Plants that have received a lot of fertilizer are in a dense fog or persistent rain.

How to recognize it: Large, brown spots that are irregular or circular in shape and lighter in color in the center start to emerge on hydrangea blooms and leaves.

Instead of misting the blooms and leaves, water the plant’s base to treat or prevent it. As soon as you notice any unhealthy leaves or blooms, you should clip them. Use a copper-based fungicide on the sick plant. Additionally helpful are liquid kelp, hydrogen peroxide, and garlic oil.

Bacterial Leaf Spot (Xanthomonas campestris)

How to spot it: The leaves and flowers developed water-soaked spots that darken and become angular. As they spread, these blotches resemble lesions and start to kill off the leaves.

Treatment or prevention: Wounds and holes allow bacteria to penetrate the plant. If these are your hydrangeas, you can take action to keep bacteria from harming them by applying copper hydroxide (Kocide).

Tomato Ringspot Virus

How to recognize it: The hydrangeas’ leaves start to turn yellow, and the plant’s growth is subpar.

Nematodes carry this virus, thus treating or preventing it is important. Therefore, be sure to use nematode-free soil or a blend. You can treat your hydrangeas with a nematode repellant if they already grow in nematode-infested soil.

How is the condition known as leaf spot treated?

It’s crucial to understand how to treat leaf spot fungus because no matter how careful you are, the day will come when those minuscule, brown circles start to emerge on the leaves of your plant. Treatment starts as soon as you notice spots on plant leaves.

To stop the fungus from spreading, immediately segregate the pot for indoor plants. Any leaf that has been harmed should be removed. Give up misting.

There are a number of secure and practical therapies available for organic treatment. Most contain copper octanate or sulfur. Alternately, you can try a more conventional treatment by misting the area with a moderate solution of baking soda, using 1/2 teaspoon (2.5 mL) per gallon (4 L) of water.

There are numerous all-purpose fungicides available for gardeners who have no objections. Before using, carefully read the label.

How do bacterial leaf spots appear?

Bacterial leaf spots typically take the form of water-soaked, brown to black lesions that are frequently surrounded by a yellow halo. The underside of the leaf frequently develops water-soaked (or also referred to as greasy) patches first. On Begonia and Pelargonium, Xanthomonas lesions have a v-shape and extend inward from the leaf margin. Necrotic lesions can be angular or oblong. In some hosts, spots may combine to provide a blighted appearance.

“Look-alike” diseases: Depending on the host, several fungal leaf spots can be mistaken for bacterial infections. Particularly for the layperson, there is no practical method to distinguish between these two. When bacteria-caused lesions are submerged in water and magnified, a visible stream of bacteria may emerge; however, streaming may not always be seen if the pathogen is dormant. Similar to this, fungal spores may be seen if the right circumstances have been present for sporulation, albeit the absence of spores does not rule out fungi as the source. Consequently, it is best to have a plant disease clinic diagnose unhealthy plants (NCSU Plant Disease Clinic).

How can leaf spots be treated naturally?

Blend everything in a gallon of water. Every ten days, spray the entire garden. When used on tomatoes and squash, this works incredibly well.

It may be possible to prevent blight by preventing leaves from coming into touch with the soil. Around tomatoes, using mulch or landscaping cloth can significantly lower the occurrence of blight.

Powdery Mildew Remedy

  • a quart of water
  • 2 tablespoons of baking soda/epsom salts or 1 splash of rubbing alcohol

Important: As you move from plant to plant, immerse pruning and gardening tools in a solution of 1 part bleach to 10 parts water to help prevent the spread of illness. With your hands, you can remove yellowed or discolored leaves, but wash your hands afterwards.

How can burned hydrangea leaves be repaired?

  • Give plants enough water, especially those that are placed in windy or sunny areas.
  • Fertilize moderately to avoid root damage.
  • Light summer pruning will aid in lessening the plant’s water requirement but may also decrease flowering.
  • Consider transplanting plants that frequently experience leaf scorch when it is feasible to do so.

Botrytis Blight (Botrytis cinerea)

The flower buds may even be fatally affected by this fungus before they bloom. Infected flower parts might also fall to the ground and infect the foliage.

Water-soaked patches on the blooms are one of the first indications. But these develop into sores that are reddish brown.

Botrytis is more likely to cause issues in cool, moist environments, such as several days of gloomy, muggy weather.

You can try to stop this illness by taking certain action. minimize the humidity. To avoid getting the flowers and leaves wet, avoid watering late in the day and just at the roots.

Keep your plants well-ventilated if you can. Pruning should be done on tightly spaced branches after correct spacing. As you prune, clean your pruning shears with bleach to prevent unintentionally spreading any disease.

Additionally, eliminate any dead or damaged flowers and leaves to stop the fungus from entering the plant. So that Botrytis cannot survive on the dead tissue, clear the area around the plant of debris.

Fungicides can be required if your issue persists. Iprodione and thiophanate-methyl are alternatives.

Leaf Spots (Cercospora species and Phyllosticta hydrangea)

On the base of the plant, cercospora appears as circular purple or brown patches. The leaves may turn yellow and drop off the plant as the diseases enlarge.

These illnesses can be avoided by watering without soaking the leaves. You can use liquid kelp, hydrogen peroxide, garlic oil, compost tea, or other remedies if your hydrangeas do become sick.

Anthracnose (Colletotrichum gloeosporioides)

This widespread fungal infection is more likely to affect plants that have received a lot of fertilizer.

The conditions that encourage infection are created by persistent rain or dense fog.

On the leaves or blossoms, the fungus causes huge brown dots that lighten in hue toward the center. One distinguishing indication is the angular development of dots around the veins.

Additionally, you can cure this condition with liquid kelp, hydrogen peroxide, garlic oil, or compost tea.

What does hydrangea anthracnose look like?

Brown dots on the leaves are the first sign that your hydrangea has Colletotrichum gloeosporioides infection. These patches will be circular or just slightly irregular, as opposed to those brought on by other infections like Botrytis (also known as gray mold). Later, each spot’s center will turn tan.

The dots may take on an angular appearance if they are near a leaf vein. Whole leaves and flower petals may grow huge, erratic, dark brown dots that resemble blotches under the right circumstances.

Cankers, which are elevated edges with sunken centers, can also form on the stems. These can be dangerous because they can girdle or wrap the branches and stems, killing them over time.

New growth could be wavy or malformed, giving the branches a twisted appearance. The hydrangea can perish from a serious illness that has spread across the entire plant and resulted in malformed stems.