By Calvin Finch Ph.D., Guest Author
There is considerable debate whether our lawns and landscape plants need to be irrigated during the winter time. It’s not a simple question to answer.
In a normal San Antonio winter, temperatures are cool, rains are common, and there’s limited plant growth. Under such conditions, irrigation isn’t crucial for well-adapted, established plants in good health.
The problem is that our weather patterns are erratic and we often have severe dry periods coupled with higher-than-normal temperatures. This is when a reasonable winter irrigation regime is essential to individual plant survival.
So what’s reasonable? Here’s my advice.
- Irrigate plants such as winter annuals and vegetables that are actively growing when the soil surface dries. (Mulch helps reduce water needs.)
- If there’s no measurable rain: irrigate St. Augustine grass every three weeks; Bermuda, buffalo and/or zoysia grass every month; and healthy, established shrubs such as hollies, viburnums and pittosporum once a month.
- Stressed shrubs and trees, including plants that are less than two years old and those planted in challenging situations such as parking lots or construction sites, should be watered every two weeks.
When irrigating shrubs and trees that are not established, water at the base as the feeder roots are still in the root ball.
Calvin R. Finch is a director at Texas A&M Water Conservation and Technology Center.