Lawn & Landscape Watering Protocol
The amount of water your lawn and landscape requires will vary greatly depending on the type of grass in your lawn. Seasonal changes and soil structure also plays a role in determining water needs. As a general rule, plants need one inch of water per week to maintain plant health. A healthy soil structure requires significantly less supplemental water.
Water deeply or don’t water at all! Light sprinkling actually does more harm than good – and this is true whether the water comes from rain, irrigation, or your water hose. If the lawn is to stay deep-rooted and healthy, it must be watered until the soil is wet to a minimum depth of eight plus inches or more. This will help your grass survive drought and hot weather conditions. Shallow root systems tend to dry out the upper layer of soil first. Light top watering will cause shallow root systems and weak plants. Save Water–Grow Organic!
It is important to know exactly how much water you are applying to your landscape. To measure, simply place a rain gauge in the zone to be watered. The gauge should be placed near the center of the arch of water. The goal is to run the watering system until one inch of water accumulates in the gauge. To test your watering system, set your timer for 15 minutes, and then measure the amount of water in the gauge. For example, if 1/4 inch collects in 15 minutes, you can calculate that 1-inch will accumulate in 1 hour.
Now that you know how much water your irrigation system delivers for each zone, it is advisable to water the zones in cycles. For example, if it takes one hour to deliver the one-inch of water per zone and to ensure deep-water penetration, water the zone in three 20-minute intervals. The first pass will swell the soil open. Then, allow the water to soak in for 20-30 minutes. Next, proceed with a second 20-minute interval that will allow the water to soak in even deeper. Complete the above process for a third cycle and you will have accomplished your goal of applying 1 inch of water with maximum water penetration deep into the subsoil with minimal water runoff or waste.
Now that you’ve watered the required one-inch, wait about 2 hours and check the zone to see if water has penetrated 8 inches in depth. This can be done by simply using a large knife or coring tool. Cut a 1-inch by 8 inch deep core and remove the plug. Check to see if moisture has penetrated to the proper depth. If so, replace dirt and grass core and press firmly back in place. If not, continue watering until an 8-inch or more depth is achieved. Please note: Each zone may not require one inch of water to penetrate 8 inches or more in depth. Some areas, for instance slopes, may need more water to achieve proper depth. Sometimes watering slopes can cause overwatering in other spots. Adjust as needed. Corners and edges may be missed by your sprinkler system and areas next to walls, sidewalks or pavement may require more water since they tend to dry out faster due to radiant heat from brick and concrete.
How do you know when to water again? Do not water again until the soil has dried to at least 2 inches in depth. Again, check the moisture depth by removing a core sample. If it takes 12 days for the soil to dry to 2 inches in depth, you will water one inch every 12 days. Each month will have a rise in temperature or natural conditions that may change the time of the soil drying. During April it may take 12 days, but during July it may only take 6-7 days to dry out. Keep a monthly calendar and make adjustments as conditions change. After your first season of watering you will have a good routine to follow. Adjust for rain and always have an automatic rain gauge timer on your irrigation system. When installing an irrigation system or up-grading an old one, have a soil moisture system installed to help better manage plant watering needs.
As you can see, it is impossible to prescribe a fixed routine for watering due to differences in soil, shade, grass species, plant systems, slope, low spots, climates and weather variations. Due to all of the elements involved, what may be good today may not be the same next month or at the same time next year. You must remain flexible and diligent in your measuring and monitoring, watering only when and where needed throughout the growing season. Healthy organic soil requires less supplemental watering. Promote plant and soil health by using Growzilla, Jackhammer and Clear 90 to optimize soil health and increase the moisture holding capacity of your soil. The best time to water is early in the morning between 5am – 8am. Please do not water at night, as it promotes disease and causes other issues within your landscape.