We’ve recently planted trees in the midst of a dry-spell and have struggled to keep them watered. We have since discovered the Tree Gator. It is a bladder filled with water that wraps around the tree. As the water slowly leaks out it keeps the tree watered for as long as a week.
We use the 15-gallon Treegator Jr for the smallest of newly planted trees. They also make a 20-gallon version for larger trees. Beats dragging hoses from tree to tree.