3 Reasons For Hawthorn Leaves Turning Black – [Remedy Guide]

Hawthorn trees are known for their beautiful white or pink flowers which makes them very popular in the landscape gardens. Moreover, their sparkling bright red berries add a different touch to the beauty. 

However, if their leaves are starting to turn black, it means something is very wrong with your tree. It also means that if you don’t immediately take it into account, your hawthorn tree’s life can be at risk.

  • Fungal Diseases
  • Insect Infestation &
  • Environmental Stress 

These are the 3 major reasons why the leaves of your hawthorn tree are turning black. You see, it’s very important to investigate the reasons so that you can take the appropriate action to prevent these black leaves from happening in the future.

The good news is, in this article, we are about to explore why the hawthorn leaves are turning black with its easy solutions.

So, without making any delay, let’s fire away–

Why Are My Hawthorn Leaves Turning Black?

1. Fungal Disease

The most common reason for the black leaves of hawthorns is due to fungal and bacterial attacks. 

You see, fungal leaf spots cause black spots on the hawthorn leaves. Eventually, these spots get larger and coalesce resulting in total black foliage. Besides, the leaves will fall off prematurely and if the infection is too severe the young hawthorn tree will be at risk of death. 

Besides, bacterial attacks also can cause black leaves. Especially when blight occurs in the hawthorns it can cause black streak marks and withered leaves. 

Control Measure

First, I prefer to completely remove the leaves that are affected with black marks as soon as I notice them. Because it helps to stop the spread of the disease any further. 

After that, it’s best to use a good fungicide that is compatible with your hawthorn trees. If you suspect a bacterial attack then apply a copper-based fungicide instead. (our pick).

Make sure to follow the instructions on the fungicide package carefully. It will tell you about the application rate and duration. If the fungicide is applied without following the proper dosage, it can be harmful to your tree.

In addition, try to improve the air circulation around your hawthorn tree because it will reduce the chances of leaf spots and will help the leaves to dry out faster in highly humid conditions. For this, you can prune out some parts of it to let more sunlight penetrate the tree.

Besides, avoid planting new trees or shrubs too close to your hawthorns. And avoid overwatering at all costs because this is one of the root causes of all fungal diseases. Water them deeply once a week and don’t wet the leaves while watering.

Also, you have to remember to clean your pruning tools with a solution of 10&  bleach or some rubbing alcohol. This action will go a long way in preventing fungal and bacterial infections. 

Interestingly, you can make the copper fungicide all by yourself if you are willing to do the work. Check the DIY Copper fungicide recipe below–

#Recipe: Copper Fungicide Recipe


  • 3 liters of water
  • 40 ml of copper sulfate
  • 5 tablespoons of Calcium hydroxide (also known as hydrated lime)


  • First off, all the buckets, spoons, and spray bottles need to be made of plastic. Because metal ones can badly react with the ingredients.
  • Use the plastic bucket and mix water with hydrated lime and stir the solution with the plastic spoon
  • Now add the copper sulfate very slowly in this solution and keep stirring the whole thing until you completely finish adding the copper
  • After that, pour this solution into a plastic spray bottle and spray very thoroughly on your hawthorn leaves
  • Make sure to frequently shake the solution while spraying because it tends to sit out.
  • Spray it twice a week on both sides of the leaves until the problem is solved
  • After finishing spraying, clean the spray bottle and buckets and spoons very thoroughly with plenty of water
  • Lastly, always avoid storing the leftover solution. Make a fresh batch every time

2. Insect infestation

Some small insects like aphids and scale insects suck the juice out of the hawthorn leaves and secrete a sticky substance named honeydew on them. As a result, black sooty mold grows over this and causes the leaves to turn black. 

Though this mold is not very harmful to the hawthorn tree, it can block sunlight to a great extent. This will eventually decrease the hawthorn’s ability to photosynthesize. Eventually, the tree will turn very weak and leggy. 

The sad thing is, these pesky pests are very small and when they start to infest it goes unnoticed unless your hawthorn trees are being checked very frequently. As a result, the attack was in huge numbers. And it causes much damage to the tree.

Control Measure

When you notice the infestation, make no delay in taking action. Get the best insecticide for your hawthorns that is equally very effective against pests and also safe for the environment. (Our pick)

Besides, encourage some natural predators like ladybugs, lacewings, and parasitic wasps to keep aphid populations in check. Plant some nectar and pollen-producing flowers near your hawthorn so that these beneficial insects will be attracted to them.

Moreover, sometimes when their population is low on your hawthorn you can use a strong jet of water to blast the aphids off the tree. This method is a temporary solution though. But this will work if you keep doing it frequently. 

In addition, you can use insecticidal soap, horticultural oil and neem oil on a weekly basis to prevent these pests from attacking again in the future. Besides, prune out the heavily infested branches. This will ease up the handling of the hawthorn tree during treatment. 

Looking for an organic way of insect control? Here is the recipe–

#Recipe 1:- In one Insect Spray Recipe


  • 2 bulbs of garlic
  • 2 onions
  • 2 teaspoons of dry pepper powder
  • 2 tablespoons of liquid dish soap
  • A  gallon of water


  • Blend the onion and garlic together in an electric mixer
  • Next, add the dry pepper powder and liquid dish soap and combine thoroughly
  • Strain the mixture with a fine cheesecloth
  • Now add this mixture to the water and mix very well
  • Pour this on the spray bottle and spray on both sides of your hawthorn leaves

Since this recipe contains peppers, remember to use gloves while spraying the solution and prevent it from getting to any skin or eye contact. But if it happens, wash with plenty of water.

3. Environmental stress

When the hawthorn tree is exposed to environmental stress conditions like drought, heat, and heavy pollution it can cause its leaves to turn black. 

At this time, if the hawthorn trees don’t get enough water then it becomes an even more serious issue for them. During the winter season, the tree can go into freezing shock and drop off all its leaves as well.

Control Measure

During drought conditions, make sure to water your tree deeply on a regular basis. But in the winter season, avoid watering your hawthorns too frequently. 

However, avoid wetting the foliage during watering because this can increase the risk of many fungal diseases. 

Also, you can spread a layer of mulches around the base of your hawthorn. This will help to retain some moisture in your plant and will also lower the soil temperature. 

Most importantly, apply a balanced liquid fertilizer so that it can make your hawthorn more strong to endure the environmental stresses. (our pick)

During the hot spells, prune back some of the branches to reduce the demand for nutrients and water requirements of the tree. If there is harsh sunlight affecting your hawthorns you can use a protective shade over your plant for that period.

Frequently Asked Questions (FAQs)

Q: How long does the hawthorn last?

Ans: Hawthorn trees have a long lifespan if it has been provided with the ideal conditions. So, It can even live up to 400 years. But usually, they last more than a few decades, even around 250 years. 

Q: Do hawthorn trees lose their leaves?

Ans: Yes, hawthorn trees are deciduous. So, they lose their leaves every year during the fall season. The leaves typically turn yellow, orange, or red before falling off. The trees are leafless during the winter however new leaves start to grow again in the spring season.

Q: Should I fertilize my hawthorn tree?

Ans: Hawthorns are not very heavy feeders so you don’t have to bother fertilizing it every month. Feeding the tree with a balanced fertilizer every year during the spring season is enough. However, if the soil is too poor in nutrition then you can feed it during the summer with a small dose of fertilizer. 


Hawthorn leaves can turn black due to environmental stresses and attacks from fungal and bacterial diseases. In addition, some pest infestations can cause black spots on their leaves too. 

Even exposure to certain chemicals or pesticides can cause hawthorn leaves to turn black as well. This is why you have to make sure you pick the right pesticides and fungicides for them. 

Protect your tree from environmental stress conditions, water them once a week and provide enough nutrients by using a good fertilizer. Soon the black leaves problem in your hawthorn will be solved. 

If you have any further queries about your hawthorn trees send them to us through the comments and we’ll get back to you soon. 

James Rivenburg
James Rivenburg
James Rivenburg

James Rivenburg is the founder of plantandpest.com, a passionate gardener with valuable experience and knowledge gained through trial and error. The website has a large community of followers who trust his tips and techniques and have succeeded with his advice. He is always Committed to helping others create a beautiful and healthy garden.

Leave a Reply

Your email address will not be published. Required fields are marked *