Water in the landscape is essential, but we tend to forget when enough is enough. On several recent site visits, I have noticed a lot of saturation in the soil. Too much water around the foundation of your home can destabilize the structure and cause water seepage, which can attract mold. Too much water also promotes diseases in the plants whose root systems are being soaked. We like to call this “Wet Feet” in the plant world. Moist is good – drowning is not.
The soils in our area have different absorption and dispersion rates. Clay soils in Appling handle water a lot differently than the sand in much of the Augusta area.
Once saturated, clay soils can take a long time to dry out depending on temperature, humidity and weather.
The sandier soils can sometimes handle almost as much water as you can give them, especially in a high heat, southern sun exposure area. Most soils in our area do a pretty good job at maintaining a certain level of water retention.
What can we do to help with too much water?
• Turn down, turn off or redesign the irrigation system to control the amount of water emitted around the home’s foundation. Most foundation plants that are established don’t need much supplemental water.
The majority of irrigation heads that are installed around a foundation are called mist heads. These can pump a lot more water than you might expect. Most of the ones I see in home landscaping can emit 2-3 gallons of water a minute. A standard irrigation design has one sprayer head’s water overlapping to the next head. That configuration can lead to a discharge of 4-6 gallons of water per minute over a not-so-large area. To put the amount of water being used in perspective, think of filling a 2-gallon watering can and pouring it on a larger house plant. It is easy to overwater.
• Change the type of spray head that irrigates around the foundation so there is more of a gentle soak on plants that don’t need a lot of moisture and a heavier volume of water on plants that do.
For instance, a holly or gardenia is drought tolerant and can die from being overwatered. Hydrangeas, on the other hand, need a good bit of water. Sometimes it is OK to cap or turn off an irrigation spray head completely.
• Purchase a rain sensor for your irrigation controller. Most newer-model digital irrigation controllers have a way to retroactively install a rain sensor that will turn your irrigation system off for a while if it rains. Some models are wireless, and the sensor can be mounted up to 300 feet from the controller. This sensor can pay for itself in about a year in water savings alone.
• Get the rain water away from the house. A roof sheds almost all of the water that falls on it. For every 1 inch of rain on 1,000 square feet of roof, the runoff is about 600 gallons of water. So, with the average roof size being about 3,000 square feet, 1,800 gallons is a huge amount of water that has to find a place to go. If there is no system to move this water away from your home, it is going to end up close to the foundation, where saturation will occur quickly. If you add in an irrigation system that pumps water into the same area where the roof water ends up, problems can mount rapidly.
Gutters are easily the best solution for harvesting roof runoff, but make sure the downspouts are extended far enough away from the foundation to let the grade of land, a swale or even an underground piping system remove the water. Be cautious of the final destination of the water after redirecting away from the structure, because forced runoff can lead to flooding in other areas, erosion and possibly illegal dumping of water onto a neighbor’s property.
So, remember that too much water can be more destructive than too little water. Protect your foundation and your plants.
Other points to remember this time of year:
• Prune shrubs for shape only and fertilize for the last time of the season.
• Check lawns for diseases and insect infestation. Treat accordingly.
• Mow Bermuda grass a notch or 2 higher to help color last further into fall.
• Continue planting fall vegetables.
REACH CAMPBELL VAUGHN, THE AGRICULTURE AND NATURAL RESOURCES COOPERATIVE EXTENSION AGENT FOR RICHMOND COUNTY, BY E-MAILING AUGUSTA@UGA.EDU.