Hydrangea leaves turning brown

Hydrangea leaves turning yellow or browning around edges

The photos you sent appear to be leaf scorch; a common physiological problem of hydrangeas. 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. Common causes include inadequate watering, exposure to strong light (sunlight or reflected light), high temperatures, or dry, windy conditions. Scorch can also occur as a result of damaged roots or stems, such as from an injury, compacted soils, or overwatering or overfertilization. Leaf scorch is most common on leaves farthest from the roots and those most exposed to harsh conditions–often the top of the plant and the sunniest side are most affected. Occasional minor damage is primarily an aesthetic concern, but severe or recurring damage may indicate an underlying problem with the plant’s health or planting location.
Also, check the moisture around the roots. These plants like lots of uniform soil moisture. If it was a potted plant that got transferred to the garden often the soil mix is very high in peat and tends to dry out quickly and hard to re-moisten. Or there may have been a very root bound root situation. Dig the plants up and check the original soil ball. If dry and root bound; loosen the roots lightly with your hand, soak the root ball in water till moist and then plant. Keep the soil uniformly moist for best growth. Light shade is helpful.
Other remedial options may include:

  • Improve soil drainage
  • Apply an organic mulch over the root zone to help maintain soil moisture.
  • Plant hydrangeas in appropriate locations. Most prefer dappled shade, especially during the hottest part of the day. Plants near reflective surfaces such as walls and fences may be more susceptible to leaf scorch. Or be prepared to water them more frequently.
  • When practical, consider moving those plants that routinely suffer from leaf scorch.
  • Light summer pruning will help reduce the water needs of the plant, but may also reduce flowering. This will not resolve the underlying cause of the damage, but may help maintain plant health in the short term, until it has a more extensive root system.
  • Provide adequate water for plants, particularly those planted in sunny or windy locations.

Additional information about hydrangeas can be found at the following sites:
http://ohioline.osu.edu/hyg-fact/1000/1063.html
http://web.extension.illinois.edu/dmp/palette/080727.html

I have 3 endless summer hydrangea in the front of my house (facin ne). they were doing good (coming from last years plant) and were about 1.5 inches wide. I came home from a weekend at the cabin and some of the leaves were wilted and brown. History: I added to acid loving plant spikes to all the flowers 1.5 weeks ago, I water them every other day and they were watered before I left. What happening and what can I do – Thanks in advance!

Wilt and browning are difficult to diagnose, as there are many factors that may be the cause: too much sun, wind, not enough water, to much water, etc. Hydrangeas tend to become especially stressed in hot sunny conditions, they perform best in morning sun or partially shady areas. Although hydrangeas prefer a lot of water they, like many other plants, are prone to root rot when the soil is too moist for too long. When they experience root rot, the plant tends to wilt, and in turn the gardener suspects the plant is dry and it needs to be watered, thus worsening its condition. If you stick your finger into the surrounding soil and feel that it is damp, they do not need more water. If you suspect root rot, send me another email and I will talk you through proper care techniques. Also take into consideration that your ‘endless summer’ has a new home and its root system hasn’t had time to fully develop. When the root system is not able to supply water to the large leaves at the same pace that they are loosing it to evaporation wilt may result, but not cause browning. When hydrangeas are over watered the leaves will turn yellow followed by black edges. We have also been experiencing extreme winds around this area, if planted in an unprotected area these winds could account for browning and wilt. Sometimes the tips or sides of the hydrangea leaves will appear to turn brown after it has suffered a dry spell or a period where the roots are not absorbing moisture well and the plant gets a good watering. This browning occurs when the leaves take up water suddenly and cells swell and burst. Continue to follow your regular watering schedule and keep me posted.

This year has been quite a rainy one and along with the weather, unwanted visitors have arrived into the gardens; namely fungus. Although the plants have been well-hydrated, which is definitely a positive, fungus disease seems to have spread rapidly; not so wonderful. The disease spreads from one leaf to another and then to the next plant seemingly unstoppable. Fungus thrives in wet, humid conditions and poor air circulation, basically this Summer season we have had. I’ve seen evidence of this fungal spread on my bigleaf hydrangeas (macrophylla), which are subject to black spotting (as are most hydrangeas). Black spotting is a fungal disease that appears on the leaves of Hydrangeae quercifolia, Hydrangeae arboreacens and Hydrangeae macrophylla.

One upside about the fungal disease, is that it is seldom fatal to affected plants.

Black spotting can originate from a number of fungal diseases, such as ANTHRACNOSE And CERCOSPORA leaf spot:

Cercospora leaf spot (Cercospora hydrangea) begins as brown or purple spots that develop centers of gray and halos of the brown and purple on the leaves at or near the base of the plant. The circular spots are often small and scattered and the leaves may eventually turn yellow-green and fall off.

Anthracnose produces large brown spots on leaves that eventually develop lighter brown or tan centers. The spots may also appear on blossoms and may appear angular if bordering a vein. Like cercospora leaf spot, the disease first manifests itself on the lower leaves of the plant in the form of purple to reddish spots.

PREVENTION

Spring pruning takes precedence in the prevention process, it’s important to remember to remove all diseased, dry, and dying leaves and stems. Remove up to one-third of the large older stems with clean, sharp pruning shears (Pruning only makes it spread more, if you are not cleaning your pruners between each cut). Trimming the stems increases aeration and reduces the dampness and humidity that cultivates the fungal diseases that cause black spots on leaves. When it’s rainy or humid, the leaves don’t dry very well, and if any of spot-causing fungus is around, the damp conditions enhance the disease. A second good time to thin is right after the plants flower. Removing diseased leaves as soon as they appear helps prevent further disease.

Clean up and remove any dropped diseased foliage from around the ground and make sure to seal it away in a garbage bag so that spreading is decreased. The fungus can become airborne and reinfect the plant if not properly disposed of. When infected leaves brown and drop, the disease spores stay in the vicinity. Depending on temperature and moisture, the problem will flare up to varying degrees year after year. The more diseased leaves you can remove and clean up from off the ground, the fewer spores will be around to re-infect. Also, put 2″ of organic mulch or compost down so that it smothers any of the spores that overwintered and are still present in the soil.

Spray a fungicide, such as Neem oil Spray, on your shrubs’ newly emerging leaves when wet or humid conditions are present. Coat them thoroughly top and bottom of leaves, repeating the treatment after rain or every 10 days to two weeks depending on conditions. Copper-based fungicides may help control bacterial leaf spot if applied in late spring. The key with any fungicide, though, is to get the spray on all the leaves before a disease flares out of control, so be sure to spray preventatively at the first signs of spotting. Make a habit of watering your hydrangeas at the base, so you don’t wash off the solution or enhance the disease with the overhead watering, leaf spot can be spread through water droplets.

When a plant is not placed in the right location or properly taken care of, it experiences stress and the plant can not combat disease to its fullest ability. Making sure that hydrangeas are well watered, don’t experience drought conditions, or too strong sun will help keep the plant healthy and strong and more apt to resist disease.

Common Hydrangea Problems

Hydrangeas are relatively easy to care for and worry free bushes that are beautiful for most of the growing season. Although most people concentrate on the hydrangea flowers, a lot can be determined about the health of the hydrangea by the leaves. Most diseases and insects attack in mid to late summer. Here are the most common questions we are typically asked and detailed articles on how to identify and fix each problem.

My Hydrangeas Won’t Bloom

This is the most common question we are asked about. The shrub looks healthy but isn’t producing flowers. Typically there are 3 common reasons why your shrubs won’t bloom. Pruning, winter damage or not enough sunlight. Click on the link to the article to learn more about this typical problem. Thankfully this is a pretty easy problem to fix.

Image of the hydrangea not blooming

Besides the bushes not blooming, there are two common categories of problems that hydrangeas are impacted by. Fungus and pests. And both mostly impact the leaves and foliage.

Brown Spots On Hydrangea Leaves

In a home landscape, brown spots on the leaves are usually caused by a fungus or bacteria. In most cases, the fungus or bacteria does not threaten the life of the plant, but the spots can be unattractive. These spots usually appear annually toward the end of the summer and fall. The following spring, the leaves emerge unaffected, and the spots from the previous year do not affect the plant’s ability to bloom. Click through to the article for more details on how to identify the problem as well as the best way for treatment.

Hydrangea Pests

If you are noticing holes being eaten in the leaves, or notice other insects damaging the leaves, you may need to treat your plants. Common pests for hydrangeas are aphids, Japanese beetles, spider mites and slugs. Of course there are several other bugs and animals that could be contributing towards the demise of your plants as well. This guide will cover the common headaches and tactics to deal with them.

Flower Colors Fade

Some hydrangeas will produce big beautiful flower-heads, but then those flowers will quick fade and turn brown or not look as pretty. While this is natural, there are some things gardeners can do to ensure the flowers stick around longer, keep their color and look healthier. The best part is most of these suggestions are relatively easy to do.

What’s Wrong With My Hydrangea?

Photo: Steve Bender

French hydrangeas may be water hogs, but extended periods of wet weather can cause them big problems. Suddenly, their pristine leaves become spotted, scorched, and dusted with powder. People in the South have every right to panic, but instead they wisely call on me to diagnose the ailments and provide solutions. Once again, Grumpy delivers.

Ugly Ailment #1 — Cercospora Leaf Spot

Image zoom emCercospora leaf spot. Photo: programs.ifas.ufl.edu/em

Grumpy gets more panicked emails about this fungal problem than any other. Small brown or purple spots appear on the leaves. As they grow in size, they develop tan or silver centers with purplish borders. Lower leaves are affected first. Then the disease moves up the plant as splashing water from rain or sprinklers spreads the spores. Seriously infected leaves drop.

What to do: First, pick up, bag, and throw away any fallen leaves to reduce the number of fungal spores. Second, don’t wet the foliage when you water. Third, spray the foliage according to label directions with Immunox, Daconil, or Natria Disease Control. Spray again next summer before the spots show up.

Ugly Ailment #2 — Anthracnose

Image zoom emAnthracnose. Photo: forums-gardenweb.com/em

Like leaf spot, this malady likes warm, wet weather and spreads by splashing water. Brown spots appear on the leaves and grow rapidly in size. Light-brown centers surrounded by dark-brown rings create a bull’s-eye effect. When a spot encounters a leaf vein, it spreads along it, forming an angular brown or black patch. Leaves turn dark brown or black and drop. Flowers may also be affected.

What to do: Write Grumpy a $50 check for being such a font of wisdom. Pick up, bag, and throw away any fallen leaves. Don’t wet leaves and flowers when watering. Spray foliage and flowers according to label directions with Natria Disease Control or a copper-based fungicide. Spray healthy flowers and foliage next summer before spots appear.

Ugly Ailment #3 — Powdery Mildew

Image zoom emPowdery mildew. Photo: nickiwoo.com/em

Small, gray to white patches appear on the leaves. They eventually coalesce, covering the leaves with a powdery white film. Unlike the previous two diseases, powdery mildew likes both cool and warm, humid weather. But the leaves must be dry for the spores to germinate on them.

What to do: Write Grumpy a second check for $25 so he can leave work early and buy a nice bottle of red wine for tonight’s dinner. Spray the foliage according to label directions with neem oil or Natria Disease Control.

“The Secret To Drying Hydrangeas”

“The Truth About ‘Endless Summer’ Hydrangea”

Hydrangea leaves turning red

Hmmm, I think I saw that happen to an Oakleaf Alice that I had (R. I. P.) three years ago, marsie80. While a red color on leaves would be normal for some oakleafs during the Fall, that one had a sliver of red on just 2-3 leaves. The color change also happened too early in the summer to be Fall color-change related… or so I thought at the time.
After a few days or weeks, the sliver of red turned brown. It seemed to affect a few leaves, not all of them. I assumed it was related to the summer at the time. The temperatures had been fluctuating wildly that year because of an incredible amount of rain but, when this happened, the rained had stopped and the temps probably were back to “normal”, which means 100s over here. I assumed it was some form of moisture problem; I had turned off the sprinkler due to the excessive amt of rain and forgot to turn it back on as time passed and the temps got warmer. I monitored that for a while and then I forgot all about it.
Leaves turning brown (and curling) usually indicates a watering issue. It is common in the summer months. Curling, by itself, can also be caused by the hydrangea leaf curler insect. Brown spots (especially those occuring away from the edges) by themselves can also be caused by fungal infections.

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