The Grass is always Greener

After it Rains

The Grass is always Greener

The Grass is Always Greener . . . after it Rains.

Folk wisdom is that growing things are always greener after a rain.  Simple observation tells us that.  We all know that no matter how much we water our lawns and landscape, even our veggie gardens, that after a rain it is like something special happened.  The turf gets greener and puts on a spurt of growth.  The landscape seems brighter and lusher. The vegetables almost always put on fresh new fruits within a matter of days.

Well, something special did happen.  It rained.  And yes, the grass is always greener after it rains! Why is that so special?  Let’s take a look at what is really happening.

All Water is Not Equal

If you are watering with tap water, you are essentially putting everything that your local water supplier puts into the water to kill the bacteria that might live in the supply system into your soil and on your plants.  These compounds are usually some combination of chlorine compounds, bromine compounds, and fluorine compounds.   Each of these is highly toxic in the right amounts.  In trace amounts, they are lethal to bacteria and other small organisms that tend to like dark wet places like pipes, pumps, and storage tanks.  Not surprisingly, these are the exact conditions that exist within healthy soil.  So, it isn’t a long leap to connect damage to your soil to watering with your local tap water.  If it kills the organisms in the pipes, it will also kill the organisms in the soil.

pH? What?

Tap water is also usually quite alkaline.  Part of that is because of the treatment that it undergoes to be made safe to drink.  The other side of the equation is the water source.  Here in Lubbock, most of our water comes from wells.  Well water, especially here in West Texas, tends to have a high pH after filtering through layers of minerals on the way into the aquifer.   The water picks up these minerals which remain in the water.

Salt Assuculation on soil beneath drip irrigation

To salt or not to salt

Many of the minerals that are in tap water are in the form of salts.  As we water our soil, these salts tend to build up in the soil.   While it rarely gets to toxic levels in our lawns and landscapes, such an accumulation can be a problem in agricultural areas where they water heavily with highly mineralized well water over long periods.  The soil can become essentially sterile because of the toxicity of the salt.

Let it Rain!

Now, let’s look at rainwater and why is the grass always greener after it rains. As surface water evaporates into the atmosphere, it is basically distilled.  All the salts and other contaminants are left behind.   All that water that gathers into clouds and then falls onto your lawn and landscape is pure.  Well, almost.  Each raindrop collects around a minute particle of dust.  The rainwater can also absorb or gather other airborne contaminants that can affect its quality.   In areas with really high levels of airborne contaminants (smog), the rainwater can become so contaminated that it is essentially an acid (acid rain).  Fortunately, in West Texas, this is not a problem.

The Ozone Connection

Lightning in Thunderstorms

As the clouds churn and move in the atmosphere, moving the water around as vapor and small droplets, several other things are happening.  This movement creates static electricity which we see as lightning.  As the static electricity discharges through the clouds, it does some interesting things.   It creates ozone.  Ozone is an oxygen compound that has an extra oxygen molecule.  The chemical symbol is O3.  In and of itself, ozone is a powerful oxidant and can be fatal in high concentrations.  However, some really cool things happen when it is dissolved in water, and it hits the ground.   The ozone infiltrates into the soil where it quickly breaks down, releasing that extra oxygen molecule, which adds oxygen to the soil.  This extra oxygen combines with other elements in the soil to help with the processes of soil aggregation and flocculation.   It makes your soil lighter and fluffier.

Nitrogen, et. al.

The rainwater also tends to pick up excess nitrogen as it swirls in the atmosphere and falls to the ground.  This nitrogen tends to be in the form of nitrates and ammoniums, which are immediately available to your plants.   These plant ready nutrients are the main reason everything greens up after a rain.  Other compounds are brought to the surface as well. Rainwater delivers the carbon dioxide which brings a source of carbon to the micro-organisms in the soil.   Rainwater can also help leach all those salts that have accumulated from your tap water down into the deep layers of the soil, well out of the root zone of most plants.  As the salts are leached away, the availability of trace minerals in the soil is enhanced. 

Do your own research

Rainwater really is the best irrigation we can get.  Second to that is catching rainwater and storing it to use at a later time.   If you don’t believe me, run a small test yourself.   Get two identical plants, put them in identical pots and water one with tap water and the other with rainwater.  Feed them identically, care for them the same and see if there is not a marked difference in how well the plants perform. 

The Grass is Always Greener

The grass is always greener after it rains! So, the next time it rains, go stand outside and let some of that precious liquid fall on you as it falls on your garden.  I can almost guarantee that you will feel better for it.  I know your plants will.

For more information about irrigation in your garden and landscape or rain catchment for your home or garden, visit our website at


More information can be found about rainwater and local water sources at these websites.

High Plains Water Conservation District

Ogallala Commons

Texas Manual on Rainwater Harvesting