‘Glenn’ Mango saplings enjoy the bright sunshine, but not all day direct sunlight. Once your trees begin to mature, they will require as much sunlight as possible. More sun will equate to bigger, juicier, fruits. For potted mango trees, you may need to move them outdoors to achieve full sun. A ‘Glenn’ Mango Tree requires at least six hours of sunlight a day during the growing season. It is best to keep your mango trees located in a south-facing area to harness the full power of the sun.