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.
This article will talk about the different reasons magnolia leaves turn yellow and how to make your bush look beautiful again.
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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Both too much and too little water can be bad for magnolia trees. Too much water can suffocate the roots, and too little water can cause drought stress. Check the soil’s moisture level before you water.
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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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Check often for common pests like aphids, spider mites, and scale. 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 problem mostly affects types that lose their leaves in the fall, and it’s the main problem that spring-blooming types have with their flowers and new leaves.
If you live in a colder climate zone (like zone 7 or further north), you should always be ready for 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.
You can still protect your new magnolia from cold weather if you really want one that hasn’t been bred to be hardy in cold weather.
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 handle having their feet wet, so give it a lot of water every two or three days until it looks 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.