Ask the Superintendent – Winter Watering Guidelines

As golfers, we know that December  21st marks the shortest daylight day of the year and, after that, we start gaining a bit of extra daylight every day. That means more golf. 

This time of year, I usually am inundated with questions around the clubs, dealing with live (plant) Christmas decorations and how to choose and care for them. I will include the top choices for live Christmas trees as an extra in this month’s column, and if you have questions specific to the live Christmas Decoration theme, just take a look at past December editions in the AVIDGOLFER archive. 

My concern is that we have had another crazy weather year that saw flooding and record winds in late spring, and then a hot and very dry mid- to late summer … stressing plants even more than our average summer. This makes it even more critical to water plants correctly throughout the winter to prevent severe damage or plant loss. 

This month’s question comes in response to our ever-changing weather. Do I need to water my lawn and landscape during the winter months? The answer is yes but, as always, there are many factors to consider. So here are some tried-and-true winter watering guidelines.

What is Desiccation?

Desiccation, by definition, is what happens when a great deal of moisture is removed from a substance. Whether that substance is a gas or a solid, it is the same process. When we talk about desiccation or winter desiccation in plants, we are specifically referring to the transfer of excessive amounts of water from leaves and into the atmosphere. This is a normal part of the plant’s respiratory functions, and losing small amounts of moisture is usually not a problem since plants are also bringing in new fluids from their roots at the same time. However, if the ground is frozen and water uptake is limited, that situation starts to be problematic. Add some strong winds that further dry out plant tissues, and things can quickly become lethal to the plant. Desiccation is a major factor in winter damage to plants. The last few winters in DFW have been hard on plants, but a healthy well-watered plant has the best chance of survival. 

Now that you understand some of the physical stresses that are at work during the winter, let us take a closer look at the strategies to keep your lawn and landscape properly watered in the winter. The key takeaway here is that proper winter watering will help your plants survive winter stresses and help prevent desiccation.

Winter Watering Basics

During winter, plants require less water than they do in the spring and summer, but they do need well-timed watering. Generally, we use one inch of water per week as an average that could move up or down based on soil type, temperature and wind. Remember, irrigation is a supplement to natural rainfall, so be aware of how much rain has fallen or is forecasted to fall when managing your irrigation needs. Try to water deeply several times per month. Trees and larger plants should be watered from the trunk outward toward the dripline, as feeder roots can extend beyond the dripline and plant uptake of the water is key. Smaller shrubs, flowers and lawns can be watered over the top of the plant on a similar schedule. 

As a rule of thumb, water when the soil is dry to the touch, or you can use a moisture meter for the technical-minded. Or for old sage gardeners, there is also the screwdriver test, where if you cannot easily push a standard screwdriver into the soil, it’s time to water. Whatever method you use, watch the results and adjust as needed. 

Temperature is a big factor in watering and water needs in plants. The temperature should not be below 40°F (4°C) when you water. Also, try to water when the wind isn’t blowing, as wind can significantly impact the amount of water delivered to a given area depending on wind direction. The timing of watering before severe cold temperatures is critical. Keeping your plants hydrated consistently and getting water into plant tissues before a winter storm arrives have a tremendous impact on the survivability of the plants, lawns and trees. Even dormant warm-season grasses such as Bermuda and Zoysia require winter watering.

Areas of Concern

There are a few areas in the landscape that are more prone to winter damage and desiccation than others, so they will need a bit more attention when it comes to water and successful overwintering. The first area that always takes the worst damage from winter stresses, especially in lawns or turf, are north-facing slopes. There are several reasons for this. First, slopes are tough to water consistently, as the higher areas are often drier and the lower areas can be too wet. Watering with a cycle approach on slopes can help where you water several times with less water instead of one single watering to allow water to be absorbed without runoff. North slopes are also more shaded in the winter due to the sun angle (shade cast in these areas are the last to thaw during snow/ice) which increases the management required to keep the plant healthy. 

These slopes are also exposed to direct line winds and, many times, it’s the combination of the drying wind coupled with extended cold that kill the plants. Extra attention to watering these areas can mean the difference between survival and winter kill. The takeaway here is to note areas that are more prone to winter stress damage and adjust your watering and other plant health strategies (fertility, plant choices) accordingly. Taking pictures and keeping a landscape/garden journal can really help take the guesswork out of the process and document successes and/or failures. 

We now interrupt our scheduled content for the promised holiday bonus feature.

Bonus Feature: Top Five Live Christmas Tree Choices and Poinsettia Facts

Balsam Fir: Is very fragrant, making it the most popular Christmas tree variety.

Douglas Fir: A very common variety, favored for its perfect conical shape and fullness. Lots of branches to hang ornaments from. 

Fraser Fir: Recognizable by its needles, which are dark green on top and silver underneath.

Scotch Pine (or Scots Pine)

Colorado Blue Spruce: noted for its texture and blue color.

Honorable mention species include Eastern White Pine, Red Cedar, Noble Fir and Leyland Cypress

When you are doing your holiday decorating, do not forget about the ever-popular poinsettia (Euphorbia pulcherrima), which bring a splash of colorful holiday cheer to any room or festivity. Poinsettias are named after Joel Roberts Poinsett and have been popular since the 1800s. They come in the classic colors, red, pink and white, and in keeping with our watering themes require water several times per week more if they are placed near heat vents. Be aware that poinsettias are tropical (native to Mexico) and will die from cold exposure if left outside or near open doorways during colder weather. Poinsettias are the second most popular plant in total sales, second only to the orchid.

Conclusions

When it comes to watering your landscape and lawns, making every drop count is important. While we water much less in the winter, the amount and timing of the watering can help our plants survive even a legendary Texas winter.