Crepe Myrtle with Yellow Leaves
Yellowing crepe myrtle leaves are never a very good sign. You’re used to gorgeous dark foliage, exfoliating bark, and abundant blossoms on this usually trouble-free tree, so it’s alarming to see leaves on crepe myrtle turning yellow. What is causing the yellowing crepe myrtle leaves? It could have one of several causes, each requiring a slightly different remedy. Keep in mind that if this yellowing takes place in autumn, it is normal, as the foliage begins prepping for dormancy with leaf color changing yellow to orange or red.
Leaf Spot
Your crepe myrtle with yellow leaves may have fallen victim to Cercospora leaf spot. If the spring was very rainy and the leaves turn yellow or orange and fall, this is likely the issue. There is no real point in trying fungicides against this type of leaf spot since they are not very effective. Your best bet is to plant the trees in sunny spots where air circulates freely. It will also help to clean up and pack out infected fallen leaves. But don’t worry too much, as this disease won’t kill your crepe myrtle.
Leaf Scorch
Bacterial leaf scorch is a big bad problem that causes leaves on crepe myrtle to turn yellow. Look for the yellow appearing first at the tips or leaf margins. If your crepe myrtle has bacterial leaf scorch, remove the tree. You should burn it or otherwise dispose of it to prevent the spread of this fatal disease to healthy plants.
Physical or Cultural Damage
Anything that damages the trees may cause yellowing crepe myrtle leaves, so this could be a source of toxicity in the environment. If you’ve fertilized or sprayed the crepe myrtle or its neighbors, the problem could be excessive nutrients, pesticides, and/or herbicides. Assuming good drainage, watering it well will often help move the toxins out of the area. Other cultural problems that cause yellow leaves on a crepe myrtle include inadequate sunshine and too little water. If the soil doesn’t drain well, it can also result in crepe myrtle with yellow leaves.