What is Wrong With the Extension Service
The Pinellas County Extension Agent Brian Niemann gets it wrong again and again and again. If you were to follow the advice given in his blog Post Skip a Week (or Two) of Watering this Winter, you won’t have a healthy lawn - you’ll have a dead dying weedy lawn.
Anthropomorphizing Plants is Poor Science
In the intro of the blog post, Brian wrote: “…and start to train your plants to need less water.”
This is false. You cannot train a plant – you can only grow a plant. Withholding water does not train a plant to do anything – it kills it. When you withhold water, the plant slows its metabolism, which slows growth. St Augustine lawns with slower metabolism and growth creates a thin, weak open turf that is less drought hardy and susceptible to weeds and pests.
The Landscape is Diverse
According to Brian Niemann: “…your landscape only needs water every 7-14 days depending on the microclimate of your landscape.”
Notice he uses the word “landscape” and not a specific plant. The diversity of plants in a landscape range from cacti to exotic tropicals and each plant with its unique water requirement. Advising homeowners to water their landscape every 7 – 14 days is foolish. If a homeowner followed this advice after a few months, the landscape would be divided into 2 groups of plants: Drought Tolerant and Dead.
Sandy Soils Rule the Microclimate
The key phrase is “depending on the microclimate”. And in Pinellas County, that “microclimate” is ruled by the soil. Our sandy soils dry out at the same rate in the summer as the winter. After rain or irrigation, our sandy soils can only hold enough water to sustain turf for about 3 days – not 7 – 14 days. Beyond 3 days and the lawn stresses, reduces roots, stems and leaves, and declines.
Sandy Soils are Like a Bucket with Holes in the Bottom
Sandy soils are like a bucket with holes in the bottom. Fill the bucket (sandy soil) with rain or irrigation water and the water leaks out until the bucket is empty. That takes about 3 days. After 3 days there is not enough water to sustain the grass. The grass goes into water conservation mode – collapsing the canopy (folded leaves), loses turbidity (footprints remain) and starts to shut down metabolic processes causing a blue-gray tint. The grass is now dying of water stress and the biological activity in the soil has collapsed. The plant is shutting down all metabolic processes and starts to slough off unnecessary roots and shoots. It is dying. A dying lawn is not a healthy lawn.
Light frequent Watering is Exactly How You Water a Sandy Soil
Brian Niemann writes: “…you want to increase the amount of time between waterings. Light, frequent watering is inefficient and encourages shallow root systems in plants.”
This may be true with clay soils that can become waterlogged with light frequent watering. But not for our Pinellas sandy soils that drain so rapidly that even heavy rains can’t waterlog the soil. Light frequent watering (every 3 days) in sandy soils is the most efficient way to keep a sandy soil moist and the turf healthy. And a moist soil encourages the plant to grow – grow roots, stems, and leaves. A dry soils encourages nothing but weeds!
Wet Feet – a phrase used by gardeners to describe a condition of plants grown in waterlogged soils. Few plants like “wet feet” – most plants require well-drained soils to thrive. A plant with “wet feet” will have a very shallow root system, mainly because there is little oxygen in the waterlogged soil and there is no reason to send roots any further to find water – it’s right there. However, to have “wet feet” in a sandy soil is nearly impossible because water drains out quickly.
What Time Should You Water
Mornings are good and so is any other time of the day. It rains any time of the day and no lawn ever died from rains in the middle of the day or from midnight thundershowers. Watering during the day helps cool down the lawn and adds humidity to the canopy reducing the water stress of hot summer days. The idea that watering at night can cause some killer disease is a fallacy considering it often rains at night and no lawn ever died from a midnight storm. The best time to water your lawn is before it is water-stressed.
I am Disappointed
Having graduated from a state university, I’m disappointed to see such poor information being published by this extension service. Their interest is not your landscape or the beauty of your home or the positive environmental impact of a healthy lawn; they just want you to stop using your irrigation.