Thuja Green Giant Trees Problems (With Proper Care And Maintenance)

There are no serious drawbacks as those trees are resistant to lots of adverse conditions and pests. However, people do face some Thuja green giant trees problems.

Those problems may appear in many forms. Yet, some think it’s the overwatering or underwatering issue and so on. 

But figuring out the right cause and failure to take proper care may result in a worse situation. 

So, I will talk about those problems and later in this article, I will share the proper Thuja green giant care and maintenance guide.

Common Problems With Thuja Green Giant Trees

For privacy or landscaping purpose, such giant arborvitae is second to none. However, homeowners face several problems during the growth of these trees and when they are fully established.

Let’s talk about those problems.

  • Bagworms Problems

Unlike pine trees and hemlock, thujas like Green Giant and Emerald green trees are not prone to bagworms. But bagworms may affect them nonetheless in some rare circumstances.

The bagworms first eat the foliate of the thuja once they affect the trees. Your trees will have slower growth and may also die!

Unless the problem has spread on a larger scale, do not use any pesticides to solve the issue. Instead, you should remove the pupae holding white & silky bags whenever you spot them.

Along with removing those bags, clip the infected foliage as well.

  • Problem With Scale Infestations

There are multi-facets problems with scale insect infestation. First, they are very difficult to spot as they are very tiny. Second, they produce a sweet liquid that mold and mildew love lot.

So, instead of spotting scale insects, you should look for the mold and mildew developments on your trees. 

If you can find them, you can fairly assume, the scale insects also invaded your trees too. 

You should take it seriously because scale infestation will stunt the needle growth and lead to other problems like browning and defoliation. You need to treat your thujas ASAP!

As it’s difficult to visually identify them, apply any good insecticide on every affected area of the trees to remove them

  • Root Rot Issue

When water those trees without ensuring proper drainage, those trees like any other trees may develop rot. This happens mostly when those trees are still young.

You can tell whether your Green Giant trees are having rotting problems by observing their dropping leaves. They will look thirsty even when they got plenty of water.

It becomes nearly impossible when the root rot has already been invaded. 

However, if the rot issue appears as mold or mildew forms on the leaves or branches, you can remove them by rubbing the clippers with rubbing alcohol or any sterile pruning techniques.

You need to rub every clip and sterile them one by one and dispose of the debris in a garbage bag. That should give your thujas a second chance.

  • Winter Damage

For newly-planted thujas, winter damage is real for their leaves. The foliage can become haggard and brown.

The only way to fight this problem is to prepare your thujas against harsher weather by reducing the supplemental water. Instead of encouraging new growth, this strategy will make them resistant to such winter damage.

  • Overwhelming Size

Of course, everyone is aware of the fast growth rate and massive size of Thuja Green Giant. That’s what makes them ideal for screens in large areas and windbreaks.

But not everyone is aware of the fact that soon they can dwarf their homes and other plants. If not trimmed timely, it can quickly overwhelm your backyard.

Instead of sudden shearing, homeowners should trim and maintain those trees year after year in a regular manner. 

Sudden shearing will result in twiggy and bare branches and they won’t be filled anytime soon!

You can take a few steps to solve this problem. 

As thuja cultivars come in various sizes, you need to pick the right one from those sizes considering the backyard and other plants you have there.

Take into consideration the future size of the surrounding plants as well. Also, plant your thuja trees keeping an appropriate distance from the fences, power grid lines, and other structures.

Thuja Green Giant Care And Maintenance

care for Thuja green giant

Being aware of the basics of Arborvitae can prevent all those problems mentioned above. 

Most of the time, people face those problems because of planting the Green Giant without having the basic knowledge about them.

Follow these below-mentioned maintenance and care guides for Green Giant trees:

  • Plant Them At Right Distance

For a proper root system, the thuja green giant needs to be planted at a minimum distance of 5 feet from each other if you are installing a hedge. If possible, you can also keep a 10-15 ft. distance as well.

This will leave enough room for the root system to develop. As a rule of thumb: the more room you allow for the roots, the healthier the trees will be.

  • Don’t Let Them Get Too Tall

For outdoor privacy or for a beautiful backyard – whatever the case may be, don’t let them grow taller than what you need. 

The taller they get the more difficult and dangerous it will become to shear. Most of the time you don’t need them taller than 8 feet high. So, make sure to keep them top there every year.

Pruning the green giants on a regular basis is good for the trees themselves as you will be cutting the leafy growth instead of cutting the large woody parts. 

That will prevent the decaying on the top of the trees from the large cuts. 

Pruning is important to keep your trees trouble-free. So, if you find that difficult, you should hire a trimming service to do that for you.

  • Careful Irrigation

You Green Giants need irrigation but you do not want to keep the soil wet as they don’t prefer wet soil. So, wherever you plant those trees in your backyard, make sure water won’t be laying there for a long time.

But as I said, those trees need their water. So, you need to provide water and ensure the root system is moisturized during the drought season.

  • Beware of Diseases and Pests

As you have seen above, such arborvitae face challenges with different pests like bagworms, leaf miners, and so on. 

Diseases like tip blight may also attack. So, when such trees are young and stressed, it’s a good idea to fertilize them on a regular basis as a proactive measure.

Frequently Asked Questions (FAQs)

Why are my Thuja trees dying?

Most of the time, a soggy or saturated soil condition leads to the demise of Thuja trees. It’s true when you notice the foliage begins to turn reddish-brown.

How long do Thuja Green Giant trees live?

Under the ideal growing condition, they can live as long as 40+ years.

Can you overwater Thuja Green Giant?

You need to keep the soil moist but make sure the soil has an adequate drainage system to avoid overwatering issues.

What is the best fertilizer for Thuja Green Giant?

The nitrogen number should be higher than the other two numbers to be ideal fertilizer for Thuja Green Giant. Fertilizers with numbers like 10-8-6, or 15-5-10, or 20-20-20 are good to use.

How do you revive a Thuja?

Thuja trees begin to die during the severe winter. To revive them, you need to prune the dead leaves whenever you notice new foliage begins to grow.

Closing Remarks

Despite having some Thuja Green Giant trees problems, they still worth ensuring privacy and for a beautiful landscape. With the proper care as mentioned above, those issues won’t be a big problem.

Let me know your thoughts about your own experience with Thuja Green Giant in the comment box. 

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4 thoughts on “Thuja Green Giant Trees Problems (With Proper Care And Maintenance)”

  1. Please Help I live in NE Arkansas I have 10 Thuja Green Giant Trees. Planted 2 years ago. I thought they were doing fairly well but noticed after this hot summer a three of them have Canker. I am sick about it. One I could cut the canker limb out the other 2 are on the trunk. If you saw them you would think they are thriving. They are 7’ tall.
    I am wondering if I made a mistake planting. I really needed a fast growing tree to help block traffic sound from the Highway behind my house.
    Any words of advice? I was going to replace 2 but today I have found a 3rd with canker. How contagious is it?

    1. In reply to Brigette:

      I’m sorry to hear about the canker on your Thuja Green Giant trees; it can be quite distressing to see disease in trees you’ve invested care and hope into. Cankers are areas of dead bark that are often caused by fungal or bacterial pathogens, and they can be a significant problem. In terms of your Thuja trees, here are some steps and considerations to manage the situation:

      Pruning: For the tree where you can remove the affected limb, prune it back to healthy tissue. Make sure to sterilize your pruning tools before and after use with a 10% bleach solution or alcohol to prevent the spread of the disease.

      Care and Maintenance: Continue to care for your trees with proper watering (especially during dry spells), mulching, and appropriate fertilization. Avoid wounding the trees, as wounds can be entry points for pathogens.

      Disease Management: For the trees with canker on the trunk, it’s more challenging because you can’t simply cut out the affected area. A tree can sometimes compartmentalize the damage and continue to grow, but this can also weaken the tree and make it more susceptible to other stresses and diseases.

      Containment: To prevent the spread of the disease, it’s crucial to avoid moving infected clippings around and to clean any tools used on the infected trees. Also, make sure not to transport the pathogens via your shoes or clothing to other parts of your garden.

      Replacement Considerations: If you do replace the trees, consider whether another species might be more disease-resistant and still meet your needs for sound reduction. A local nursery or your county’s cooperative extension service can provide advice on what trees might be suitable for your area and needs.

      Expert Advice: You may want to consult with a certified arborist or a plant pathologist to confirm the diagnosis and to get specific recommendations for treatment. They might suggest applying fungicides or other treatments, though these can be variable in their effectiveness.

      Contagiousness: The contagiousness of the canker depends on the specific pathogen involved. Some canker diseases are spread by water splash, insects, or contaminated pruning tools. An expert can give you more information on the disease affecting your trees and how to prevent it from spreading.

      Sound Barrier Alternatives: While waiting for new trees to grow, or as an additional measure, you might consider building a berm or installing acoustic fencing to help reduce noise from the highway.

      Remember, the success of these trees can be influenced by many factors, including planting location, soil conditions, and the local environment. Don’t be too hard on yourself, as even with the best care, trees can sometimes succumb to disease. Focus on the health of the remaining trees and the steps you can take to protect and care for them.

  2. It is October in Mid Atlantic and I am noticing a few of our trees have bright orange foliage throughout. The parts that are green look healthy. I first noticed it on one tree but now see it on several adjacent trees. Are my trees infected with something or is this normal shedding?

    1. Reply to Rita Evans Eder:

      In the mid-Atlantic region of the United States, October is the time when many trees are expected to change color and shed their leaves as part of the natural seasonal cycle. Deciduous trees, such as maples, oaks, and beeches, typically display a range of fall colors, including bright oranges, reds, and yellows, before their leaves drop.

      Here are some factors that could explain what you’re seeing:

      Seasonal Change: If the bright orange foliage is uniform and the leaves look healthy (not spotted, curled, or deformed), it’s likely a normal seasonal change. Trees prepare for winter by breaking down chlorophyll, which is the green pigment in their leaves, causing other pigments like carotenoids (yellows and oranges) and anthocyanins (reds and purples) to become visible.

      Tree Species: Some species are known for their bright orange fall foliage, such as sugar maples and certain oaks. It’s also possible that the trees you’re observing have a naturally more vibrant autumn coloration.

      Sunlight and Weather Conditions: Sunlight and temperature influence the intensity of fall colors. Sunny days and cool (but not freezing) nights tend to produce the most striking autumn displays.

      Health and Stress Factors: While bright orange foliage is typically a sign of the natural seasonal process, trees under stress may also show color changes earlier than expected. This stress can be due to drought, root damage, or other environmental factors.

      Disease or Infection: Certain diseases can cause discoloration and leaf drop, but these are usually accompanied by other symptoms such as spots, lesions, or deformities on the leaves or bark.

      Considering the information provided, if the foliage is uniformly changing to a bright orange and the trees seem otherwise healthy, it is likely just normal autumn leaf shedding. If you are still concerned about the possibility of disease, it could be beneficial to contact a local arborist or your extension service to get a professional diagnosis. They can help determine whether the color change is healthy and typical for the species, or if there is an underlying problem that needs attention.

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