Water Water Everywhere

The recent months of April and May were especially dry. I don't believe my landscape received a drop of rain during that time and it showed.  A few plants in my wildflower garden simply gave up the ghost. It wasn't really possible to water these as deeply as they needed and it showed me that they really weren't as adapted to my landscape as I had hoped. I will not add them again as much as I'd like to.  Drought is a common phenomenon here in Florida and we must choose plants that are willing and able to abide it - in reasonable degrees.  

The need for water is something most gardeners understand.  It is vital for nearly every function a plant requires. It lies on both sides of the equation for photosynthesis, for example. Without adequate water, a plant simply has to shut this vital function down. Without photosynthesis, a plant cannot grow or flower. If it's severe enough, it can't do anything and it will die.  Water also is the vehicle for bringing in nutrients and for moving them throughout the plant's "body."  Nutrients are not absorbed through the foliage, regardless of what you might see on a container of commercial fertilizer. They are pulled into a plant, dissolved in water, via the plant's roots. Without sufficient water, a plant can not receive the nutrients it requires.  

The return of the rainy season, therefore, was a blessing as my soils were, once again, moist and capable of supporting the needs of my plants, but it also was a cause for concern as too much rain is also deadly. I have lost plants in the past from getting too much water.  This seems to be the part of the overall equation that many gardeners don't fully understand. My guess is that we kill more plants by overwatering them than we do by not watering them enough.  Water is deadly to a plant when it suffocates the roots.  A few plants can "hold their breath" underwater and survive for long periods of time in saturated soils, but a great many others will drown when held underwater for just a day or two.  This aspect is one of the most important ones to understand when choosing plants for a landscape.  Understanding your plant's tolerance for saturated soils is far more important than pH, fertility, and the like.

Plants must breathe, just like animals do. Though they release oxygen during photosynthesis, they use it just like we do for their metabolic requirements.  As plants burn energy to live and grow, they do so under oxygenated conditions and they do this all with their roots. It makes no difference if their leaves and stems are out in the open air, breathing occurs through the roots and most plants keep their roots firmly established in soil. Soil is a combination of mineral particles, water and air. The balance of air and water is critical to a plant's health. Too much air means too little water, but too much water in the soil means a concomitant dearth of air (oxygen) and suffocation.

I used to believe that our native plants that thrive in sandhill and scrub communities did so because they required far less water. I've come to realize that they thrive more on living in sandy soils that allow more air to their roots during the summer rainy season.  If you dig down into scrub sand, even during relatively dry times, you will find moisture in the root zone. No plant can live without sufficient water at their roots. Scrub and sandhill soils are not really "dry", they are porous.  It's that porosity that allows the roots to breathe - even after a major rain event.  

My soils here in my new landscape seem to be fairly natural, but my site was part of a former flatwoods. There is a clay hardpan beneath the surface sands and this makes those surficial soils very wet following long periods of heavy rain. I've had to factor this into my planning, but every year as we enter hurricane season, I still hold my breath a bit wondering if the plants I've chosen can hold theirs long enough for oxygen to once again reach their root zone.