Magnolia trees are hardy for flowering trees that grow in a wide range of climate zones. A mature magnolia is nearly indestructible, healing from all kinds of damage caused by pests and diseases that kill more delicate trees.
So, when your beloved magnolia starts looking faded and its leaves begin to yellow, it can be a cause for concern. There are a number of reasons that a magnolia’s leaves would change color. Some of them are a natural cycle in the life of the tree, while others are an indication that there is a problem.
Whatever the issue is, large or small, it’s always good to know what is going on. Addressing it early will allow you to correct the issue before it leads to more damage. It will also allow the tree the ability to begin repairing itself. Let’s talk about some of the predominant reasons that magnolia leaves turn yellow and see if we can’t help nurse that tree back to its original glory.
Deciduous magnolias naturally change color in the fall when the weather begins to cool. This color change is generally in the yellow/gold/bronze family. Leaves that are turning these colors are just reaching the end of their life, and the tree is going dormant.
The leaves will turn color and fall, and in the spring the tree will grow new, healthy leaves. When you see this starting to happen, there’s really no major cause for concern.
There’s nothing to fix in this event. While you may be concerned that your magnolia’s yellow leaves could be due to another issue, a good way to make this determination is to look for buds.
If your magnolia is losing leaves, but has formed buds and the buds look healthy, your tree should be just fine. If the buds are also looking damaged, you may have a more serious issue.
In evergreen magnolias, trees periodically drop leaves as the leaves reach the end of their lifespan and new growth is created. It is natural for magnolia leaves to yellow as the tree redirects nutrients to that newer growth.
This is also a common occurrence as the tree prepares to bloom. Nutrients are redirected to the growing buds and some of the older leaves will naturally lose their place.
Maintaining the right balance of nutrients and water will help keep your magnolia looking its best year-round. Fertilizing during the growing and blooming season will maintain the maximum amount of old and new growth.
Don’t panic if there is a leaf drop in the middle of the summer. Just be on the lookout for buds!
Poor soil quality is the number one factor in nutrient deficiency. Magnolias like soil with a decent amount of acidity. Soil that is too alkaline will inhibit the tree’s uptake of minerals such as zinc, iron, and manganese.
Acidic soil breaks down the nutrients that magnolias need to the extent that they are able to best absorb and utilize.
Most soil is not deficient in these minerals, but the tree can’t absorb them without the proper level of acidity to break them down. You can solve this problem by acidifying the soil. Adding organic matter to the soil is the most natural and long-term solution.
Pine mulch and needles work well, as well as fallen leaves from neighboring trees. Commercially available soil acidifiers, like elemental sulfur also serve this purpose.
If you know that your soil is adequately acidic, and your leaves are still looking undernourished, it may be time for some fertilizer.
Magnolias don’t need to be fertilized often, but they do benefit from some added nutrients, particularly during times of extreme water fluctuation. If there has been more rain than usual, or not enough, your magnolia could be having difficulty absorbing enough nutrients from the soil.
A nitrogen-heavy fertilizer three times per year will keep your magnolia flush with the extra nutrients that keep it looking green and healthy. But you should test your soil before you add nutrients to see if there could be another deficiency. Simply spread the fertilizer on the ground around the trunk and if there is no rain expected, water it in deeply.
Leaves are the first place that your magnolia will let you know it is thirsty. If the leaves are looking yellow and droopy, there’s a good chance your tree needs a long drink. The younger the tree, the more common you will encounter this issue. Mature magnolias are quite drought-tolerant.
Young magnolias need regular watering to help them establish roots. A shallow root system is a weak root system, so establishing roots is important.
Planting during the rainy season is a great way to help this along naturally. If you aren’t getting regular enough rain to keep the ground moist, watering twice a week is good for newly planted magnolias.
Place a hose at the base of the tree and allow it to run for until the water puddles, this should give the ground a good soaking.
Apart from ‘Green Shadow’ and maybe one or two other M. virginiana varieties, magnolias do not like soggy roots. Soggy roots open the tree up to fungal infections, which grouped together constitute root rot.
When root rot occurs, the first signs of a fungal infection in a magnolia will be yellow leaves. The leaves are the farthest part of the tree from the roots, and when the roots are damaged or not able to take in enough nutrients, the leaves are the first part of the tree to suffer.
Avoid planting magnolias in areas with poor drainage. Magnolias are versatile in the types of soil they tolerate, as long as they have good drainage.
If your magnolia is already established in a space that stays wet, avoid any additional watering. Make sure to fertilize adequately so that there are enough of those nutrients to go around. Lots of water means the nutrients in soil are diluted, which can make it difficult for a plant to absorb enough.
Magnolias are admired for their stunning flowers and lush green foliage. But as a gardener, seeing those vibrant leaves turn yellow can be worrisome. If your magnolia bush has yellowing leaves, don’t panic. With proper troubleshooting, you can get your tree back to good health.
In this article we’ll explore the various reasons magnolia leaves turn yellow and provide solutions to restore the beauty of your magnolia bush.
Common Causes of Yellow Leaves on Magnolia Bushes
There are several factors that can cause yellowing on magnolia leaves, Here are some of the most frequent causes
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Overwatering or underwatering Both too much and too little water can stress magnolia trees Overwatering suffocates the roots while underwatering causes drought stress Inspect the soil moisture before watering,
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Improper soil drainage: Wet, compacted soil deprives roots of oxygen. Improve drainage by amending soil or planting in raised beds.
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Soil pH imbalance: Magnolias prefer mildly acidic soil with a pH of 5.0-6.5. Alkaline soil can prevent nutrient uptake. Test and amend soil pH if needed.
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Nutrient deficiencies: Lack of nitrogen, iron, zinc and other nutrients due to unsuitable soil pH or composition can yellow leaves. Fertilize to correct deficiencies.
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Sunscald: Too much direct sun can burn leaves. Young trees need protection on southern exposures.
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Pests: Insects like aphids can sap nutrients from foliage. Apply horticultural oils or insecticidal soaps to control infestations.
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Diseases: Fungal issues like verticillium wilt turn leaves yellow. Improve growing conditions and prune affected branches to help recovery.
Restoring Soil Balance for Healthy Roots
As magnolias are sensitive to soil conditions, imbalance is a leading cause of yellowing leaves. Follow these tips to optimize soil health:
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Test soil pH yearly and amend to maintain acidity between 5.0-6.5. Incorporate elemental sulfur or aluminum sulfate to lower pH in alkaline soils.
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Improve drainage by adding organic material like compost. Or plant in raised beds in poorly draining areas.
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Mix in balanced organic fertilizer when soil testing reveals deficiencies. Apply chelated iron if iron is lacking.
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Mulch around the tree to retain moisture and moderate soil temperature. Use acidic mulch like pine needles that magnolias prefer.
Providing Proper Irrigation for Magnolias
Magnolias need a consistent supply of water, especially while establishing. Here are some best practices:
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Water deeply 1-2 times a week during dry periods, applying 1-1.5 inches of water. Feel the soil to determine need.
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Increase frequency during periods of drought and extreme heat. Wind and exposure to direct sun also increase water needs.
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Reduce watering during cool or rainy stretches to prevent saturated soil.
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Water early in the day to allow foliage to dry out, preventing diseases.
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Install drip irrigation or soaker hoses to target the root zone efficiently. Avoid overhead sprinklers.
Controlling Pests and Diseases
Left unchecked, pests and diseases can weaken magnolias over time:
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Inspect regularly for common pests like spider mites, scale, and aphids. Remove by hand or use insecticidal soap sprays.
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Prevent weevils from damaging new growth by applying horticultural oil in early spring before buds open.
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Improve air circulation and avoid wetting foliage to prevent fungal issues like leaf spot.
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Disinfect pruning tools to prevent spreading diseases. Sterilize after cutting out infected branches.
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Promote vigor through proper care as magnolias can better withstand and outgrow minor pest or disease damage when healthy.
Ensuring Suitable Placement for Optimal Growth
Magnolias thrive in sites with excellent drainage and ample sun. Keep these placement tips in mind:
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Select a spot with full sun to light shade. Young trees need protection on southern exposures.
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Plant on a slope or raised bed if drainage is poor. Avoid low areas where water collects.
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Shelter from strong winds which can dry out foliage. Install screens or windbreaks if needed.
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Space multiple magnolias at least 15 feet apart and 25 feet from structures to accommodate mature size.
With the right growing conditions and care, magnolia bushes will reward you with years of spectacular blossoms and lush, vibrant foliage. By identifying and correcting the cause of yellowing leaves, you can restore the health and beauty of your magnolia tree.
Late or Early Frosts
This issue applies mainly to deciduous varieties and is the number one issue that affects the flowers and new foliage of spring-blooming varieties.
When growing magnolias in colder climate zones (think zone 7 and north) there is always the possibility of a late frost. Many varieties bloom in late winter and early spring. They will sprout leaves around the same time, or very shortly thereafter.
If a magnolia blooms and leaves out before the last frost, you are likely to lose at least a portion of the flowers and foliage to cold damage.
Fortunately, there are hybrid varieties that have been bred specifically to combat this issue by blooming 2-4 weeks later than their parent plants. Planting a variety that has this characteristic is a great way to solve this issue.
If you have your heart set on a magnolia that hasn’t been bred for cold hardiness, it’s still possible to take some preventive measures.
Avoid planting with southern exposure, as southern exposure will encourage a tree out of dormancy earlier, by several weeks in some cases. Giving your magnolia some protection from cold winds is also a great idea if you want to avoid cold damage.
Avoid These 5 Five Mistakes When Growing and Planting Magnolias
FAQ
How do you fix yellow leaves on magnolia?
Sometimes an iron or other nutrient deficiency can result in yellowing leaves on magnolias. Get a thorough nutrient test done on your soil and figure out what the tree lacks. Buy and apply a fertilizer that offers the missing nutrient.
How often should you water a magnolia bush?
Magnolias can tolerate wet feet so water heavily every other day or every 3 days until it starts to look better.
How to fix yellow leaves on bushes?
‘Hungry’ plants such as roses, sweet peas, and dahlias, need a rich, fertile soil and may develop yellow leaves if short of nutrients. You can resolve this in the short term by adding a balanced liquid fertiliser around the roots of the plant, but increasing soil fertility is the best option in the long term.
How to revive a magnolia bush?
Your magnolia just needs extra water. Give it a good soak every few days until the rain picks up or the temperature goes down. The damaged leaves will not be salvageable. Pruning off any dying magnolia tree foliage will help the tree focus its resources on healthy growth.