Monday, May 23, 2011


This past week I’ve been asked by several people “How much water should I be putting on my yard each week?”

The quick answer is one inch of water per week, including rainfall. I look at one inch per week as a starting point, and then adjust for other factors. These factors include soil type, wind exposure, slope in the yard, berms, heat and exposure to the sun.

A clay soil is going to hold more water for a longer period of time than a sandy soil. When watering a clay soil, if you put out too much water at once, it will begin to run off instead of penetrating the soil. Wetting agents (Aqueduct, Possum’s Wetting Agent with Bio stimulants) and organic matter (Cotton Burr compost) will help water penetrate clay better.

Water tends to pass through sandy soils quickly. If they receive too much water at once, the water tends to leach through the soil past where the plant roots can access it. Wetting agents (Aqueduct, Possum’s Wetting Agent with Bio stimulants) and organic matter (Cotton Burr compost) will give sandy soils better water holding capacity.

Wind exposure can also play a big part in how much to water. An ocean front or lake front lot with a constant breeze will require more water than a land-locked yard in the suburbs that is protected from wind. Position of trees, fences, houses or other wind breaks can also affect wind exposure. If your yard is very windy you will have to water more than a yard that is more protected from the wind.

Depending on the elevation change in your yard, you could require more water. Some houses sit up on hills that slope down toward the road. These sloping yards require more water. In the Lowcountry, this is less of a problem than an area in the mountains or hills.

If you have a lot of landscape berms, be sure these areas are getting enough water. Many berms are made with landscape grade fill dirt (i.e. sand) that tend to dry out quickly. Being up on a hill, they have more exposure as well as slope, therefore they require more water.

Just as we need to drink plenty of water, so do the plants and grass. Some areas near sidewalks and streets are getting cooked! The soil surface temperature is often well over 100 degrees. Give your trees, flowers and turf a drink!

Exposure to the sun also affects the amount of water needed by a yard. If your yard is shaded by a neighbor’s house or trees, it will require less water than if it is in the wide open sun. Different areas of the same yard will require different amounts of water based on the exposure to the sun.

Always try to water early in the morning so your turf does not stay wet too long and encourage fungus. Turf gets wet at night through guttation and dew. By watering early in the morning (5-7 am) you are not extending that wet period. If you water at 9 am and the grass has been wet all night, you could be giving disease the opportunity (moisture) it needs to flourish.

As you can see, many factors determine how much you should water. Next week we will talk about different ways to measure water.

Always read, understand and follow product label. The product label is a Federal Law.