During the fall, crape myrtle leaves turn attractive shades of orange, yellow, and red. However, if your crape myrtle leaves turn yellow at other times of the year, it could be a problem. This article will look at eight common causes of yellow leaves on crape myrtles.
8 Common Causes of Yellow Leaves on Crape Myrtle
Overwatering
Crape myrtles (Lagerstroemia spp.) are drought-tolerant deciduous shrubs that like to stay slightly moist. Overwatering can be a big problem for crape myrtles, leading to other issues like root rot. If your crape myrtle has yellowing leaves, it may be sitting in waterlogged soil.
Overwatering your crape myrtle can lead to root rot. Root rot symptoms include yellowing or wilting leaves and brown, mushy, or smelly roots. Crape myrtles need well-draining soils that still hold some moisture. Remove any rotting roots and add some grit or sand to the soil to provide extra drainage.
Underwatering
Yellow crape myrtle leaves can also be a sign of underwatering. While crape myrtles are drought-tolerant, they still need water to survive. If your crape myrtle doesn’t get enough water, it will produce weak growth and wilting leaves.
Established crape myrtles need watering once every two weeks when the top few inches of soil feel dry. You’ll have to water crape myrtles more frequently in dry, hot summers to stop them from drying out completely.
Too Much Sunlight
Crape myrtle shrubs thrive when given at least six hours of full sun daily during the growing season. However, too much direct sunlight can damage crape myrtle leaves, turning them yellow. Crape myrtles that get too much sun may also have burnt or scorched leaves.
Crape myrtles should get most of their full sun during the morning when sunlight is less intense. Direct afternoon sunlight is harsh and intense, especially during the summer. In hot climates, plant crape myrtles somewhere that gets full sun in the morning and partial shade in the afternoon.
Not Enough Sunlight
Crape myrtle leaves can also turn yellow if the plant doesn’t get enough sunlight. Crape myrtles grow best in full sun but can tolerate partial shade in hot areas. However, crape myrtles cannot tolerate full shade.
Crape myrtles that don’t get enough sunlight often fail to flower. Plants in the full shade also develop weak, stunted growth.
Too Much Fertilizer
Crape myrtles are adaptable plants that thrive in nutrient-poor soils. Crape myrtles also don’t need a lot of fertilizer despite being fast-growing plants. Giving your crape myrtle too much fertilizer can even scorch the leaves and turn them yellow.
Fertilizers can contain strong chemicals and salts, so must be diluted before you apply them. Fertilize established crape myrtles once a year in the spring with slow-release fertilizer granules.
Not Enough Nutrients
Although crape myrtles thrive in nutrient-poor soils, they still need some nutrients. If your crape myrtle doesn’t get enough nutrition, it can develop yellow leaves and weak, stunted growth. It may also fail to produce any flowers.
Plant crape myrtles in chalky, loamy, or sandy soils with some added organic matter. This provides nutrients gradually throughout the year. Fertilize crape myrtles once every spring with slow-release fertilizers.
Diseases and Pests
Crape myrtles may develop yellow leaves if they suffer from diseases or pests. Common crape myrtle diseases and pests include aphids, Japanese beetles, leaf spot diseases, and powdery mildew. Cercospora leaf spot and bacterial leaf scorch are two problems that are likely to turn crape myrtle leaves yellow.
While leaf spot can be dealt with, bacterial leaf scorch is often terminal. Unfortunately, this means you’ll need to get rid of your crape myrtle. Eliminate pests using horticultural oils or insecticidal soap.
Age
Crape myrtles may develop a few yellow leaves due to natural aging. The leaves may also turn lovely shades of yellow during the fall before the leaves drop. Crape myrtles typically live for approximately 25 to 50 years and constantly grow new leaves.
Once your crape myrtle reaches 10 or 15 years old, it may occasionally produce yellow leaves. As long as the leaves look healthy and there aren’t any symptoms of other problems, don’t worry too much.
How to Care For Crape Myrtle
Growing Environment
Crape myrtles thrive in Zones 6 to 9 and require sheltered locations to protect them from strong winds. Most crape myrtles can survive winter temperatures as low as -5ºF. In colder climates, grow crape myrtles in containers and protect them by wrapping them in fleece or bringing them indoors.
Sunlight Requirements
Crape myrtles need at least six hours of full sun every day. The morning sun is preferable to direct afternoon sunlight, which is more intense. South or west-facing locations provide crape myrtles with the ideal amount of sunlight.
Soil Conditions
Crape myrtles require well-draining soils that still hold a bit of moisture. They can survive in nutrient-poor soils and are drought-tolerant once established. Crape myrtles prefer slightly acidic soils with pH levels between 5.0 and 6.5.
Watering
Water established crape myrtles every two weeks or so to keep the soil moist and more frequently in hot, dry conditions. Water newly planted crape myrtles once or twice a week for the first couple of years. This helps the plant establish a good root system.
Fertilizer
Feed older crape myrtles once during the spring with a slow-release fertilizer. This provides plenty of nutrients for the development of new leaves and flowers. Fertilize newly planted crape myrtles once a month during their first growing season.
Pruning & Trimming
Crape myrtles vary in size, impacting how often you want to prune them. Dwarf varieties won’t need much pruning because they only grow between 2 and 6 feet tall. However, some types of crape myrtle grow as shrubs or small trees that reach approximately 30 feet tall and 15 feet wide.
Rather than pruning too often, assess your garden first and determine what type of crape myrtle you can accommodate. Choose a crape myrtle that stays at a manageable size for your space. This allows you to reduce the pruning you’ll need to do.
Yellow Leaves on Crape Myrtles FAQs:
How often should I water my crape myrtle to avoid yellow leaves?
In my experience, crape myrtles grow best in well-drained soil and do not like to be overwatered. Water deeply but infrequently and only when the top inch of soil feels dry to the touch.
How do I know if my crape myrtle has a nutrient deficiency?
The easiest method is to look for physical symptoms such as yellowing leaves, stunted growth, or leaf drop. A soil test can also help determine nutrient levels and deficiencies.
Can I treat yellow leaves caused by environmental stress?
Environmental stress, such as extreme temperatures or wind damage, can cause yellowing leaves, but the plant will usually recover independently with proper care and watering.
Should I prune off yellow leaves from my crape myrtle?
It is generally not necessary to prune off yellow leaves unless they are significantly affecting the plant’s overall health or aesthetics. Sometimes, yellow leaves may simply signify natural leaf shedding as the plant ages.
How can I prevent yellow leaves on my crape myrtle?
Proper watering and fertilization, regular pest and disease monitoring, and providing appropriate environmental conditions can help prevent yellowing leaves on your crape myrtle.
Wrapping Up
Crape myrtles can develop yellow leaves due to overwatering, underwatering, incorrect lighting, or too much fertilizer. Check other symptoms to determine the exact cause. Provide good growing conditions by watering your crape myrtle once every two weeks and providing full sun. fertilize crape myrtles once a year during the spring.
For more, see our in-depth guides to crape myrtle deer resistance and whether crape myrtles are toxic to humans and animals.
Edd is a budding content writer and gardener living in the United Kingdom. He has a bachelor's degree in Creative and Professional Writing and has written for several gardening publications online. He is passionate about nature and sustainability with a focus on gardening and wildlife.
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