Thursday, February 12, 2009
Winter Lawn Watering...Yea or Nay?
We've had quite a few calls at the Extension Office about whether or not folks need to water their lawn in winter. The City of Austin water dept. generally discourages this but with the drought folks are concerned about losing their lawn. I spoke recently with Dr. David Chalmers, turf specialist with Texas AgriLife Extension Service and the following comments are the results of that conversation.
Basically in the winter you need very little supplemental water. The combination of cool temps, periodic rainfall (most years), and the turf being basically shut down due to cold weather results in very little water use by the plant. However, this year is definitely an exception. It has been very dry for very long. I've noticed significant dieback of turf in lawns that were not irrigated fairly often in the summer and fall. This decline is continuing in the winter months.
If you have not received a rain in the past few weeks of at least 1/4 to 1/2 inch your soil is probably very dry and your grass is likely suffering, especially in sunny areas and those with more foot traffic. These areas will benefit greatly from an application of about 1/2 inch once a month while it is still "winter" and in the absence of rain. Even in the winter our St. Augustine lawns need adequate moisture to keep the growing points of the grass hydrated. This moderate amount of moisture is usually adequately supplied by nature, but this year those growing points along with runners and roots are desiccating to the point of near death. Even if the grass plant is not lost, an adequately hydrated grass plant will come out in spring growth faster and stronger than a semi dessicated one.
A complicating factor is the disease Take-All Patch. It destroys roots making the grass plant more susceptible to dry soil conditions. Take-All is a common problem in Texas lawns and infected turf areas are much more likely to die from dry conditions than non infected lawns. Additionally, drought stress seems to strongly predispose turf to Take-All infection which researchers believe occurs primarily in the spring and fall seasons.
Strong turf growth means good, dense coverage which means less compaction from foot traffic, less weed invasion and better intake of rainfall and nutrients (less fertilizer runoff).
I hope this helps bring some clarity to the issue of winter watering. To put it simply, most years we don't need to worry about it; this year we do.