by Ellen Zagory, Director of Public Horticulture
Plants are curious creatures. Unlike us, they cannot get up and get a drink of water when they are parched. By nature, they are rooted to the spot and rely on Mother Nature or a nearby gardener to supply water.
When any plant—including one labeled “drought tolerant”—is planted, its roots extend only as far as the potting soil in which it came. Over the next few months, new roots will begin to grow into the surrounding soil. During the first winter, any new plant will need regular soil moisture to establish a root system. This requires the gardener to be vigilant in monitoring the young plant, the temperature, the wind, and the amount of rain, and supplying moisture when the plant needs it.
Here are five tips for establishing new plants to make your garden truly drought tolerant:
1. Plant in fall because, as the weather cools and the rains come, evaporation is reduced and soil holds moisture longer. Therefore, your new plants will need to be watered less often. If drought continues, you will need to water just enough to keep the plant from wilting. (Planting in spring is good too, but just expect to use more water to get the plants established.)
2. Water deeply and frequently the first dry summer season. In warm weather, recently planted plants may need to be irrigated as frequently as every other day, especially if it is windy. The roots of a young plant need moisture to grow out into the surrounding native soil. Growing a large root system the first season will help the plant survive the next year as irrigation is reduced.
3. Distribute irrigation water evenly, being sure to wet the soil ball from the container as well as the surrounding few inches of native soil all around the plant. Plants cannot move water from one side to the other. If you water only one side, you will have growth only on one side. Watch for wilting and water if needed.
4. Reduce irrigation frequency the second summer, but apply enough water to wet the top 18 inches. Apply water slowly so that it penetrates into the soil and does not run off. In heavier clay soils, water should be applied slowly, over a long period, to penetrate the entire root zone. If runoff is a problem, run short applications of water, let the water soak in and repeat.
5. Cover the soil with a thick layer of organic mulch, like wood chips, to reduce evaporation, smother weed seedlings, keep the soil cool, and reduce erosion.