Watering basin around a newly planted tree. Photo: ucanr.edu
To ensure proper watering the first year after planting, that is, the year in which plants are settling in and will need more water than when they are fully established, why not form a watering basin around each new plant?
This technique is used mainly with trees, shrubs and conifers because they tend to be slower to establish than herbaceous plants and also because they are usually a good size at planting and therefore require a greater quantity of water each time you irrigate. However, it can also be applied to any plant, especially if it’s in a situation where it is likely to need frequent watering.
A water-holding basin is simply made of a berm of soil up to 6 inches (15 cm) high all around the root ball. When you water, simply fill the basin with water. The water will then percolate into the soil exactly where the plant needs it!
When the plant is well established, usually after a year, just remove the basin and then the plant will benefit from the same watering as neighboring plants. Besides, after the first year, the roots will have (hopefully!) outgrown the size of the basin and water should be more widely applied to encourage continued expansion of the roots.
The presence of a watering basin doesn’t mean you can’t mulch your new planting. In fact, mulching is always wise, helping to keep the soil more evenly moist and preventing weed development. Just cover the soil in the basin and even the berm itself with 3 to 6 inches (8 to 10 cm) of your favorite mulch.
Adapted from an article originally published on August 27, 2015.