Cycus revoluta "Sago palms," which are not true palms, are related to pine trees. These slow-growing trees are hardier than most other members of their genus. They will survive temperatures as cold as 15 degrees Fahrenheit, according to the University of California Agriculture and Natural Resources Service. Sago palm leaves often show the first visible signs of insect infestation, soil nutrient deficiencies and other problems. Ask your local county extension office for information on soil testing and pesticide use for your area.