If you were unhappy with the results of last year, then yes, change is good. However, i think you're "barking up the wrong tree". IE, more frequent mowing likely wasn't your problem. If you want to go 4" (but 3.5" is good for your location too) Mow when the grass is 5" tall. This might be 3 days from last mowing, or it could be 8. Grass growth will be dependent on many factors, but calendar day is not one of them. I fear if you only mow on fridays, you will break the 1/3 rule eventually. This will rip the grass blades, which turns the tips brown, and will leave a brown hue to the yard. Also verify your blades are sharp, and spinning at the proper RPM for your mower.
Water, like mowing, shouldn't be done with a calendar to the extent you are looking at it. Most turf requires 1" of water per week, whether its from mother nature or you, and all at once. The goal is to get that water DEEP! The deeper roots push, the more likely they are to survive droughts and prolonged heat waves. But even 1" per week needs to be flexible. In spring and fall when it's cooler and there is less evaporation you don't need as much water. When it's over 90 in a heat wave and there is increased evaporation, then you'll need more than 1" a week. How long will it take you to apply 1" of water? You'll need to perform an irrigation audit to find out. Good example of how stunning this really can be.
ken-n-nancy said:
MsTin said:
They arrived. I have 12 zones and placed them during a 30 minute run on one zone and got barely anything in the gauges! Can this be right?
Are your gauges okay? I mean, like there isn't a drain hole in the bottom of them or anything? If not, then, yes what you measured is much more likely to be right than anything that we can tell you from online!
In general, irrigation systems typically put down much less water per hour than people realize. It's common to think that watering each zone for 30 minutes is a lot of watering, but depending upon the water pressure, nozzle size, placement of heads, etc., I've generally observed that watering significantly (especially if trying to do 1" of water a week all in one watering) takes MUCH longer than people typically think. In the zone where I was just moving sod this morning, it takes me 37 minutes to provide 1/4" of water. Yes, an inch of water in that zone requires 4 * 37 minutes = 148 minutes = 2 hours, 28 minutes.
People who have never measured the output of their sprinkler system are generally stunned to find out how little water they've actually been applying!
Based on your watering routine of last year, you were providing inadequate water to your lawn. I don't know how much 45 minutes ever other day will give you, but what i do know is that all your plants roots were probably on the surface baking in the heat. Latent ground temps at 1-2" depth will be several degrees high in the summer than 4"+. Also 1" these soil temps fluctuate more rapidly than at 4". Also, don't exclude mother nature. If you get a big storm roll through that drops 2" of water, then you don't need to water for that week. I know you wanted to change the watering to 2 hours per zone, and that is likely a good step as that'll be bringing you closer to 1" per week (which gets that water deep!) but every other day will be too much water. The grass does need to dry out some... We don't want a peat bog.
Here is an excerpt from an article about improper watering
Irrigation practices performed in the spring, when maximum growth of shoots and roots occurs for cool-season turfgrasses, may well dictate how well turf will perform in the summer. Irrigation frequency and quantity can affect root growth, shoot growth and the balance of roots to shoots, as well as other physiological processes, such as carbohydrate availability, thereby affecting plant tolerance to summer stress.
Allowing surface soil drying between irrigation or infrequent irrigation typically reduces water loss due to slower vertical shoot growth and stimulates root penetration into deeper soil profiles by promoting carbon allocation into roots and reducing carbohydrate consumption of the shoots. In contrast, frequently irrigated turfgrasses (soils that are kept wet constantly) use more water than turfgrasses that receive less frequent irrigation and also promotes shallow root systems, which limits water uptake from deeper soil profiles where water may be available. Deficit irrigation is applying water at the quantity lower than the maximum amount of water evapotranspired from the turf (often measured at ET rate) with little or no loss of aesthetic turfgrass quality or field playability. Deficit irrigation has been associated with increases in water use efficiency. The level of deficit irrigation, however, varies with turfgrass species, soil types, and climatic conditions. For example, some cultivars of Kentucky bluegrass were able to maintain acceptable turf quality with 80% ET irrigation while 60-80% ET irrigation was adequate for tall fescue during June-September in loamy soils in Manhattan, KS.
Either infrequent or deficit irrigation may induce mild water deficit, leading to pre-conditioning or enhancement of physiological hardiness of plants. Infrequent or deficit irrigation promotes deep rooting, facilitates water retention (osmotic adjustment) mechanisms, and activates antioxidant stress-defense systems. Such mechanisms have been found in various plant species, including Kentucky bluegrass. Therefore, infrequent or deficit irrigation may be practices in spring for effectively promoting summer stress tolerance of cool-season turfgrasses. Spring is the best time to pre-condition plants for combating summer stress.
I know you stated you have sandy soil and I am not doubting that, but have you done a soil test lately? What's your Organic matter percentage? Increased organic matter will help the soil retain moisture for the lawn, as well as retain minerals for plant uptake.
The biggest take-away is to throw away the calendar and learn to read the grass. Let the grass tell you when it's time to water and mow. Make notes of how the turf responds to different periods of weather. That way, if you see a stretch of 90 degree temps, you'll have an idea of what the turf will do and can be ready when for it.
