Established Palm Tree needs watering 1-3 times a week. Adjust your watering depending on the season. Palm Trees grow more during warm months and slow down during cold months. Watering once a week in the winter should be enough.
Do mature palm trees need watering?
Most palms will only require watering only if the top 2 inches or so of the soil has dried out. Palms do most of their growing during the summer's warm months so they will need a lot of moisture to keep up with the expelling of energy they require to grow.
How do you care for an established palm tree?
Palms prefer a moist, humus-rich but well-drained soil, but will grow in most garden soils with the addition of compost and organic matter. A soil pH between 6 and 7 is suitable for most palm species.