The sago palm (Cycas revoluta) isn't a true palm and shouldn't be treated as one. Sago is a cycad, a group of ancient plants that were abundant during the Jurassic Period, 210 million years ago. How often to water a sago palm depends on temperature and how much sunlight it receives. Plants in warm sunlight require more frequent irrigation than those grown in shady conditions. The sago palm thrives when grown in dry soil and may suffer if over-watered.
Plant the sago palm so the crown rests just above the surface of the soil so excess water isn't trapped around the crown.
Allow the soil to almost completely dry before watering the sago palm slowly and deeply. Use a drip irrigation system or a soaker hose to spread water around the plant. You can also set a standard garden hose to a slow trickle at the dripline.
Water a sago palm that's grown in a container when the soil is almost dry. Add the water to the soil slowly until it drips from the bottom of the container.