At room temperature, water is a colorless, tasteless, odorless substance composed of hydrogen and oxygen gases, joined and cooled to a liquid state. H2O molecules dissolve many other things into goo only microbes and plants would consume.
Aqueous solutions flow inside plants. Cut a fresh lettuce leaf or head, and the stalk bleeds white “blood.” Bite a ripe fruit to taste its sugary juice. Sap appears on cut wood.
Most water gets its start in earth’s cold atmosphere where gases form into rain, which falls and soaks into the topsoil, then percolates down to saturate lower clay and rock pores to form the water table. About 10-20-percent of rainfall descends farther into aquifers– the porous bedrock below the water table.
Topsoil is the eroded loose rock particles and organic matter upon which we walk and garden. Air and water park in its empty spaces, cling to and soak its particles and other matter, which are necessary to produce nutrition for plants and animals that create soil fertility.
Obtaining topsoil and maintaining its moisture is a southern Denton County gardener’s number one concern. The blonde to gray-black local suburban dirt is most often a variety of tight clay subsoil.
Builders and developers clear natural topsoil down to this heavy stuff to construct foundations on more solid ground, because subsoil particles are separated by pores, so small air and water have difficulty penetrating. It has an infertile reputation.
If damp garden soil is hard to crumble or dig, it is clay. Drench it and water will either (a) pool on top, creating soggy spots that drown most plants by the roots–and harbor our friends the mosquitoes–or (b) slip between the lawn and its dirt to spill across the sidewalk, then run down the gutter into the sewer.
The gardener’s first line of attack is to pile on true topsoil that is a 50/50 mix of sandy loam and organic matter. Don’t cheat on the proportions.
Bagged “landscape mix” will work. Vegetable gardens flourish in 12- to 18-inches of the stuff. Improve lawns by spreading and watering in a couple of inches of true topsoil once or twice a year. Starving plants respond to topsoil with its lip-smacking air, water and rotting organic matter.
The second line of attack is to adjust the automatic watering system. Turn it on, then watch how much time elapses until water appears on the nearest sidewalk, or pools in low spots– about 12-minutes in flat areas and six-minutes on sloped grades.
Program each zone to stop before runoff or pooling begins, then reset the system to run several consecutive cycles until a table knife shoved four- to six-inches into the soil comes up speckled with damp earth.
In theory, a Metroplex yard or garden dampened to a six-inch depth only needs a drink once a week during summer heat. This presupposes the presence of genuine topsoil under the plant life, mulched bare spots and daytime temperatures under 100-degrees.
In winter, dormant lawns can go weeks without water, but they do need a soaking now and then during droughts.