As our unusually dry summer continues in Minnesota, this is a great time to think about smarter ways to water your yard and garden. The same source of water supplies our kitchen taps and our garden hoses, and reducing water use helps protect this vital resource for everyone. At the same time, we’ve spent months lovingly tending our gardens, and we certainly don’t want our plants to die in the late summer heat! How can we conserve water while keeping our prized plants alive?
First, know how much water your plants actually need. Vegetable gardens need about one inch of water per week. If it rains during the week, you only need to water enough to bring the total up to one inch. It’s best to water deeply but less often to promote deeper, healthier roots.
Even if the top of the soil looks dry, the soil may still be moist an inch or two down, so take a look before you start watering. A soil moisture meter is a great tool to understand exactly how dry your soil is – or just use your finger to feel the soil below the surface.
It’s common to overwater lawns, especially when using automated sprinkler systems. To encourage your lawn to grow deeper roots and become more tolerant to drought, try to irrigate about once per week, just enough to wet the soil to a depth of six inches. This could be as little as a half inch of water, depending on the weather and your soil type. Setting your mower at 2.5 inches or higher can also help shade the soil, reducing the amount of water needed. Additionally, try to position your sprinklers so they don’t water impermeable surfaces like sidewalks or driveways.
It’s best to irrigate in the early morning to allow water to sink in before it evaporates in the heat of the day. This also gives leaves time to dry before air temperatures cool down at night, reducing the risk of plant diseases.
Using soaker or drip hoses reduces evaporation and targets water at the base of plants, right where they need it. You can even lay out soaker hoses under your mulch to retain even more water. It’s also an easier way to water – no need to stand outside and water by hand, just turn on your soaker hoses (and don’t forget to turn them off again)! If you do use a regular hose or watering can, water slowly enough that the water soaks in and doesn’t run off to the side or wash away soil.
If you can collect rainwater, this is a great way to water landscape plants while reducing municipal water use. It also reduces runoff into streets and waterways. Keep in mind that water from rain barrels is not considered drinkable because it hasn’t been tested for water quality and may contain contaminants from your roof or other sources. Therefore, you should avoid using rainwater to water edible plants. However, rainwater is a great option for ornamental landscape plants! If you’re looking to add a rain barrel to your landscape, Hennepin County sells rain barrels at a discount each spring. Keep an eye out for next year’s sale, which is scheduled to start March 1, 2022.
Finally, choose plants that are well-suited to your landscape and can tolerate periods of drought. Many shrubs and trees are drought-resistant once they are established, including sumac, spirea, ninebark, smoke bush, ginkgo, and Kentucky coffeetree. When planting new shrubs and trees, water regularly until they are established. Once established, you only need to water shrubs and trees when the top six to nine inches of soil are dry and there is no rain predicted for several days.
For more information, check out the University of Minnesota Extension Yard and Garden website. Extension resources are written by experts and contain the latest and most reliable research-based information. Happy gardening!
Lauren Bethke is a Hennepin County Master Gardener Intern with a passion for homegrown vegetables, pollinators, and everything green. She lives in Hiawatha with her husband and pets.