Q. I have four sago palms and two are turning yellow. The two which look best were bought from a local nursery and the two which don’t were bought from a building mass marketer, They are all planted in rock mulch and watered on drip. They each get about 15 gallons each a week. They are now pushing new growth. I screened the soil they were going into when planting them and put in a lot of peat moss to amend it. They get sun all day long. I tried some local supplements but they don’t seem to be helping. Readers sago palm or cycad A. On your cycads, or sago palms, it is stress. Looks like the yellowing is from high light combined with high temperature stress. The rocks are not helping since it makes the area hotter from radiated heat. Put some shade over it but the damage is done and those fronds cannot repair themselves. You have to rely on new growth to cover the damaged growth. So it will look bad until that happens. That is my best shot at it.  They will not do well with rock mulch. They don’t do well if the soil doesn’t drain easily either. They really want to have rich, organic soils, mixed with their roots, to do well. Even though they are somewhat tolerant of dry soils, they are not drought tolerant. The worst exposures for sago palm will be hot south or west facing exposures near heat reflecting walls with rock mulch at their base. The best exposures are east or even north exposures with lots of indirect light with wood mulch at their base and plenty of air movement. The best soils have been amended richly with compost and the soil covered in wood mulch (not bark mulch) that decomposes with time. Be careful of watering too often since they will get root rot if the roots stay wet for too long. In that type of environment they can handle full sun but still not the rock mulch.