Landscape needs irrigation during the winter season

Thursday, December 11, 2014

Oklahomans already have seen some snow and freezing temperatures, and winter has not officially arrived. While homeowners and gardening enthusiasts may want to stay bundled up indoors, it is important not to forget about your landscape.

It is not uncommon to go several weeks without precipitation during the winter months, said David Hillock, Oklahoma State University Cooperative Extension consumer horticulturist.

“Although most plants are in a dormant state, they still use water, especially evergreens. Lack of adequate soil moisture is often a major cause of winter damage.” Hillock said. “If a cold front with freezing temperatures is forecast, water the landscape at least a couple days in advance. Moist soil is better able to provide plant roots protection from sudden drops in temperatures than dry soils. Be sure to water only when the temperature is well above freezing during the day.”

He also suggests being careful to avoid overspray or runoff onto streets and sidewalks as the water could freeze at night and become a hazard to motorists and pedestrians.

Pay particular attention to plants in raised beds, plants in areas protected from precipitation such as under large overhangs, and broadleaf evergreen plants. During dry winters, broadleaf evergreens should be watered once a month.

When there is little or no soil moisture present, plants can become desiccated. In addition, it is more likely root damage will occur.

“Take advantage of bright, sunny days. A sunny day on moist soil helps warm the soil and root area, which in turn reduces the amount of time the roots will be exposed to cold, winter temperatures,” he said. “Keep in mind moisture must be available below the frost line or frozen soil. When the soil freezes, if moisture isn’t present in soil pore spaces, moisture is pulled from plant roots to form the ice crystals. This results in desiccated roots, or what some would refer to as winter kill.”

Hillock noted too much water can cause problems in the winter as well. Cold, wet soils can lead to rotting roots. In addition, very wet soils can encourage winter weeds to germinate and flourish. It is best to water only every two to three weeks and apply just enough water to moisten the top 6 inches of soil.

“If you have potted plants under a porch or patio covering or the eaves of your home, remember these plants will need watering since they often receive little natural precipitation,” he said.