Building a watering berm around a plant's base is a practical watering method that creates a soil ridge to hold water.

Building a berm is a common basic practice in gardening and agricultural production; it means piling soil into a ring-shaped ridge around the base of a plant, also called a berm or watering basin. Once it is built, a shallow water-holding pit forms around the plant, and when you water, the water is held inside the ring and can slowly seep down to the roots instead of running away uselessly across the ground.

The main purpose of this practice is to improve water use efficiency. For newly transplanted trees and nursery stock, watering in after building a berm lets the roots absorb water fully and makes the soil fit more tightly around the roots, which helps the plants recover from transplanting and survive. In dry seasons, the water-holding ring can also reduce water loss and make every watering more effective. In addition, when applying fertilizer, scatter it inside the ring and then water, so the nutrients can be carried by the water and concentrated at the roots.

Building a berm is not complicated. Generally, with the plant as the center, use fine crumbly soil to pile a ridge along the outer edge at a radius based on the spread of the canopy or slightly smaller. The height depends on the size of the plant, and the ridge should be properly tamped down so it is firm. Note that after several waterings or rainfalls, the soil ridge may be washed out or sink, and it should be repaired promptly when you notice it. In the rainy season or in rainy regions, watch out for standing water inside the ring, and if necessary dig a ditch to drain it, to prevent the roots from being soaked for a long time and causing root rot.

Generally speaking, open-field fruit trees, street trees, landscaping nursery stock, and garden flowers and shrubs planted in the ground are more likely to need berms, while potted flowers usually do not need this practice because the pot itself can hold water. Mastering the timing and technique of building a berm clearly helps improve transplant survival rates and later growth.