Watering and misting should occur daily, especially during the summer growing season. Maple trees don't like to sit in wet roots at night, so plan to water your tree each morning with a gentle misting in the afternoon sun to keep the leaves cool. If you live in a cooler climate with more moderate daytime summer highs, it's fine to go a day or two between watering. But, if the sun is high in the sky, it's crucial to water at least three times per week.