The reason for this is often due to problems with the roots of the tree. There may be damage from underground cables, lines, pipe work, etc. The soil itself may be poor. A good starting point would be to test the soil.
This could be a number of problems. High heat, over fertilizing, high light, over watering, under watering, look more into the problem so you can diagnose it.
Leaf curl is a disease of the tree and if left untreated your popular tree will eventually die. The curling is caused by a fungus. Over time the leaves will become thicker and softer. Eventually the amount of leaves (or fruits) will decrease. To care for your popular tree treat the fungus with a natural plant cleaner.
It sounds like your trees leaves have gotten a sunburn I only this because it happened to mine and they may all fall off the tree but don't worry watch close and pretty soon you will see new buds on the branches.
My poplar trees leaves are curling due to its nature.That tree is one of the type in the classification of poplar trees.When i bought the small palnt of poplar tree, i selected the plant with curly leaves which is perennial.The tree with curling leaves usually spreads crown.
The leaves will curl if the winter season sets in.This is due to the extreme cold kills the cells and curls them.Another big problem is the presence of worms in the leaves called wewill; eat the coatings and the color pigments, make the leaves to curl and die.
Your leaves can be curling because the trees are dying due to bugs. It can also be curling because you have storms coming and the leaves will curl for rain.
