With drought conditions looming, many homeowners are turning to automatic irrigation systems to conserve water. Simply having an irrigation system will not result in water efficiency in your yard,however. A system's efficiency is only as good as the design and maintenance.
Mistake No. 1: Never adjusting the timing for the system
Homeowners will put in an irrigation system that is set to come on three days each week for 15 to 20 minutes per station. A well-calibrated spray irrigation system usually will distribute one-fourth to one-half inch in that amount of time.
That is a standard summer setting, but it is not good year-round. Irrigation timing should be adjusted throughout the year.
Grass and landscape plants use more water, about 1 1/2 inches per week, in the summer because of high temperatures, longer days and high winds. Spring and fall typically have more moderate temperatures and thus only require three-fourths to 1 inch of water per week.
Grass and many plants are dormant in the winter and temperatures are even cooler so grass only needs about one-half inch each week.
Ask the Garden Pro
Q. I have a tomato plant that was looking great but the bottom leaves are turning yellow and dying even though it is still growing and flowering. What should I do?
A. It sounds like nitrogen deficiency. As the tomato plant continues to grow, it redirects nitrogen from old leaves to new growth, thus causing your lower leaves to yellow and die. The solution is simple. If you have some extra grass fertilizer with a high first number (nitrogen), sprinkle a couple of tablespoons around each plant. That should give your plant a boost and stop additional leaves from yellowing near the bottom of your tomato.
Send questions to Michael Womack at firstname.lastname@example.org
Mistake No. 2: Not conducting an audit of condition, coverage
Turn on your system and check for broken or misadjusted heads. Replace heads if needed. Readjust heads that may be spraying on sidewalks, driveways or buildings. Map out your system so you know which heads come on with each station.
Next, you will need at least 10 small containers to collect water, and more is better; tuna or cat food cans are ideal for this task. For each irrigation station, set all of your containers between the spray heads of one station. Run the system through a cycle and measure the water in each can. Ideally, you should have the same amount in each can, but expect some variation.
Large differences may require an expert to redesign your system.
Mistake No. 3: Excessive runoff
One common inefficiency seen in both irrigation systems and even the hose and sprinkler approach is over-watering to the point of excessive runoff. You should not have large amounts of water running down the drain.
Mistake No. 4: Mid-day watering
Early morning watering is the best option while temperatures and wind speeds are typically at their lowest levels for the day.
Lower temperatures result in less evaporation. Lower wind speeds up improper water distribution and runoff associated with wind.
Mistake No. 5: Not incorporating drip irrigation or sub-irrigation
Systems with drip irrigation in flowerbeds under mulch are more efficient than those strictly with spray heads.
Sub-irrigation is used rarely in the Coastal Bend. Although viable for our landscape, these options may not be the best choice because spray heads do help wash off salt buildup from the evening sea breeze for homes near the water.
Dr. Michael Womack is a horticulturist and executive director of the Corpus Christi Botanical Gardens & Nature Center. Contact him at wmwomack@ grandecom.net