Planning for Water Shortages
The Garden Hotline receives many calls from people concerned about water shortages in summer months. Typically July and August in the Northwest net one inch or less total rainfall. Some years, June and September can be drier than normal and contribute to a lack of water for your garden in the summer. When dry summers follow a winter of low snowfall (minimal snowpack in the mountains), landscapes can be at risk due to drought conditions and possible water restrictions from local utilities. Here are a few things you can do to help prepare your plants for possible drought conditions.
Get to Know Your Soil
You need to know what kind of soil you have to determine how frequently and how much you will need to water. Use the “Growing Healthy Soil” brochure from Saving Water Partnership to help you understand how to evaluate your own soil. This guide can help you determine how much and what type of soil amendments and mulch you can use to conserve water once you’ve determined your soil type. For additional information on soil, you can download the Drought Resistant Soil fact sheet from ATTRA.
Practice Smart Watering
Water deeply but infrequently, and base how much water you apply on the plant’s requirements. The “Get to Know Your Soil” fact sheet mentioned above can help you determine when to water depending on plant type. For newly established trees and shrubs (planted within the past year), you will need to water them once every two weeks, possibly once a week during dry months, and maybe even twice a week if you have particularly sandy soil. For plants installed this year, you may need to water twice a week during the dry season, even if the plants are considered drought tolerant. All plants take approximately 2 years to become established. Be aware that few plants can go an entire summer without water even after becoming established. Be sure to check your soil’s moisture levels frequently throughout the summer and particularly during July and August, our driest months.
Using a soaker hose to water your trees, shrubs, and other plants helps you save water. It also reduces disease problems because the hose delivers water directly to the plants’ roots, not their foliage. Get directions on using a soaker hose. Many local nurseries and hardware stores carry soaker hoses in their irrigation sections.
If you already have an automatic sprinkler system, you may be eligible for a rebate on an upgrade for your system. See if you qualify.
If you have a lawn, water it deeply rather than frequently. Learn more about watering your lawn. You might also consider letting your lawn go dormant during the summer months. The lawn should still be watered once per rainless month to minimize stress to the grass. Water slowly to avoid runoff. Keep an eye on weed germination because a dormant lawn is less able to compete against actively growing weeds.
Regardless of what you will be watering, the best time to water is in the morning in order to minimize loss of water from evaporation and the development of disease.
Mulch can aid in moisture retention as well as weed suppression. It is important to be sure that your soil is moist before mulch application. Organic mulches such as grass clippings or wood chips work best because they help build the soil in addition to saving water and reducing weeds. You can acquire arborist chips for free from local tree trimming services. The chips tend to be delivered in large quantities, up to 10 cubic yards or more. If this amount is too large for your needs consider organizing a delivery with neighbors on your street. You can also mulch with compost, leaves (shredded or partially composted are best) and grass clippings (be careful not to apply too deeply as grass can compact and ultimately shed water you apply to the landscape). Apply mulch 1-2 inches thick around smaller plants and 2-4 inches thick around all trees and shrubs. Leave a few inches of breathing space around the stems and trunks of your plants to prevent disease. Mulch out to the dripline of your plants or cover the entire planting bed where applicable. For vegetable and other annual gardens mulching with compost, leaves, grass clippings or even the weeds you are pulling from the garden is preferable to wood chips. Be sure not to use noxious weeds or any weeds that have gone to flower to avoid contaminating your plot with a new crop of weeds!
While we can’t predict what each summer will bring, caring for your soil, mulching, and practicing good watering habits will help your garden stay healthy throughout the dry months and keep it healthy all year long. For additional questions on your lawn and garden, please contact the Garden Hotline.