As of October 1, 2020, central Douglas County has received roughly 24 inches of rain over the same 32-inch period, compared to our 30-year average.
We have only received 1.8 inches as of March 1, 2021, making this the driest March, April, and early May in the last 30 years.
Our county and much of southwest Oregon are currently classified as unusually arid to extremely arid. The current 90-day forecast for summer 2021 predicts that this current drought pattern will continue without significant rain.
Another indicator for the coming dry summer is that the electricity flows along the South Umpqua are already at a low summer level and that the water demand for cities like Roseburg starts early.
In a typical winter month, the city of Roseburg uses approximately 4.5 million gallons of water per day. In a typical summer month, water consumption in Roseburg will rise to over 10 million gallons per day. Most of this increase in water use is directly related to the watering season. With this dry start to the 2021 growing season and our normal dry season in June, I would like to remind gardeners of some ways to use water in our landscapes and gardens.
Most homeowners pour the water on their lawn in the summer. By reducing the total irrigated area, you can save large amounts of water. Focus on watering a small area near your patio or lawn and let some edge areas dry out with just one or two applications of water a month. The arid areas return quickly when the autumn rains return, especially if you’ve watered them a few times over the summer.
Focus on giving non-native shrubs and trees an occasional deep soak. A deep soak or two per month is sufficient. Native trees like oak and madrone can handle a dry summer. If your trees aren’t new seedlings, turn off the water.
If you have rare or very expensive new trees and shrubs, know their moisture needs and take care of them.
Use mulching throughout your landscape to reduce evaporation and keep the soil cooler. Compost-like mulches can also improve the soil’s moisture storage capacity. Keep surface mulch layers less than 3 inches thick and loose to allow for good moisture infiltration.
If mulches like Douglas fir bark are too thick and allowed to dry out, they can repel water, making late summer very stressful for your plants. If you think this is happening in your landscape, simply use a rigid steel rake to break up the layer of mulch to allow the water to penetrate.
Another way to use less water is to improve the efficiency of your watering by applying only what the target plants need. When irrigating water lawns up to 3-4 cm deep, flowers and vegetables up to 12 cm deep, bushes 12-15 cm deep and trees up to 24-30 cm deep.
Lawn, flowers and vegetables require a maximum of two applications per week, bushes and trees two applications per month during the hot summer season.
Watering in cool mornings and using drip irrigation or drinking hoses when possible will also improve your application efficiency.
Steve Renquist is the Horticulture Extension Agent for the OSU Extension Service in Douglas County. Steve can be reached by email at steve.renquist@oregonstate.edu or by calling 541-672-4461.
