Q. My star jasmine leaves are covered with a whitish plaque. The leaves are turning yellow and falling off. I have noticed the green leaves are only at the end of a branch and bare to the main stem. The plant is approximately two years old and facing east on the side of a patio. What can be done? Star jasmine with whitish spots on the leaves. A. I took a look at the picture and I saw the white spots on the leaves but I could not determine what it was from the picture and your description. I can only tell you about some general problems with star jasmine.             First of all, star jasmine will do very poorly in desert soils if the soil was not amended with compost or a good soil amendment at the time of planting. Their roots will not tolerate soils that drain water poorly as well. They do like soils covered with organic mulch.             They tend to get root rot diseases in these types of soils and they will develop yellow leaves along with leaf drop just like you are describing.             However, the white spots are a bit of a mystery. Star jasmine has milky sap in it stems and if the stems are cut they will drip a milky sap on the leaves so watch for that. If they were pruned recently they might have the milky sap dripping on leaves.             This would probably be unrelated to the yellow leaves and leaf drop you are mentioning. Bottom line, don’t plant star jasmine in our desert soils without amending the soil a lot with compost or other suitable soil amendment. Consider organic mulches on the soil surface.