Watering

By Donna Porter

Summertime is upon us in the tropics and that means hotter temperatures and weeks and/or months void of the cooling, refreshing, life-giving rains.  To any gardener, be they home-gardener or professional, this can only mean one thing – water, water, water. Visitors who have spent time in Costa Rica in our rainy season, may find it hard to believe that watering is a necessity here, but the natural cycle of the rainforest does include a dry period for flower and seed formation of the natural vegetation. This is why the native vegetation/indigenous plants can withstand these dry times, moreso, than the imported, exotic species.

A plant’s roots serve two main functions.  They serve to anchor the plant and keep it upright and intact, and they serve to uptake valuable water and nutrients from the soil and deliver them to the upper portions of the plant. As always, there are some exceptions, as with epiphytes like orchids and bromeliads. The roots of these plants act mainly for anchoring and it is their leaves that serve to absorb moisture and nutrients from the air or other sources.

Yes, watering seems like such a menial task that anyone should be able to do, but watering correctly can save time, money, your plants and, of course, helps to conserve this precious natural resource that could one day become very scarce and unavailable.

Watering has always been one of my favorite work tasks. It has always brought me a sense of calm and satisfaction; an ingratiating feeling of being the provider of a source of life.  I will even go as far as claiming that watering plants is therapeutic to our mental and emotional well- being.  In most cases, watering gives instant results. You can see, right before your very eyes, the plant come back to life and transform from sagging and wilted to a strong and turgid form.

All too many times, I see gardeners watering (or I should say spraying the foliage and ground) with a water pistol attached to the hose-end and standing two or three meters away. This only serves to wet the foliage and moisten the soil.  I explain to the gardeners with whom I work that watering with a pistol is comparable to throwing a glass of water over the head of a thirsty person; it cools them momentarily, but it does nothing whatsoever to actually quench their thirst.

For locals that live here and have hired-gardeners watering for them (and gaining all the benefit) my first recommendation is to dispose of, hide, break, do whatever is necessary so that a water pistol is not used to water plants. The strong spray of a water pistol is great for cleaning the foliage by removing dust and insects, but  it does more harm than good by eroding the soil around the plant’s roots and therefore exposing them. The best, all-around garden tool that I have ever found is my own hands and fingers.  No fancy, store- bought gadgets can compare to the versatility of our own appendages; plus we never have to scramble around trying to figure out where we last left them.  Your very own fingers, and thumbs, are the best devices to use to control the type of spray, or the distance of the spray, coming out of a hose. You can create a hard stream, a long stream, a soft fan, a wide fan, a trickle, a flood or you can bend the hose and, walla, you stop the water altogether.  I have tried numerous, expensive watering devices and have always replaced them with….. my fingers. A long-handled water wand with a water-breaker similar to a shower head, though, is best for watering rows of potted plants because it gives the most uniform distribution, but for the typical outdoor garden, let your fingers do the magic.

Watering deeply, softly and less frequently is the best method of watering rather than brisk, shallow, frequent waterings.   Deep waterings encourage plant roots to grow deeper, following the moisture into the soil’s depths, while shallow watering encourage roots to stay more near the soil surface.  Plants with shallow root systems will dry out much quicker and will require more water, whereas plants that are watered deeper and have developed deeper root systems can go longer periods between waterings.  The first two years are most critical for good root establishment for newly-planted trees or shrubs, so be sure to take the time to thoroughly water these during dry periods.

Another important measure that I recommend to keep your garden or other valuable plants alive and flourishing during dry times is to make “saucers” around them.  My gardeners call them “platos” or “casas”, and these are particularly important on slopes. This is done by simply digging out the soil from behind the plant and adding it to the front area of the plant to create, more or less, an earthen dam or wall. The lower area in the back will serve to hold water near the plant, as will the earthen dam in the front, for a longer period and give the water more time to absorb into the root area rather than running-off down the hill.  This also works in gardens or around plants that are planted on level ground. Simply create a full “saucer/plato” around each plant. Fill the “saucer” to the brim with water and allow it to absorb and repeat this at least once.  If you spend the extra time to create saucers and water in this manner, you will save an enormous amount of water and your plants will be most appreciative.

Oscillating- type sprinklers (mariposas), indeed, are less work than hand watering, and I will admit, are fun to watch and provide an instant cooling sensation by means of evaporative cooling.  But, unfortunately, they are the least water conserving and least efficient method of watering.  These work best for lawns and smaller plants. The frequency of watering will depend on a few factors including your garden’s soil-type, sun exposure and wind exposure. Of course, plants in full sun will require more frequent waterings than those in shade, as will gardens with sandier soils.

And, don’t forget the mulch. Mulching around your plants prevents moisture evaporation from the soil and keeps soils cooler.  Composted leaves, manures or any mixture of organic matter (preferably composted) that you can find can be used for this.  In the US, home & garden supply stores offer an amazing (almost entertaining) array of mulching materials like bark chips, but, living in a place like Quepos, Costa Rica, one must learn to improvise.

So, unroll that hose, make use of those fingers and water, water, water. Get wet! Watch the birds! Marvel at the beauty around you and enjoy the task at hand. Your friends and family may wonder which anti-depressant you are taking, when in fact, you are only reaping the therapeutic benefits of watering the garden.

Donna is a Horticulturist and has been living and working in Manuel Antonio for 6 years.  She consults, designs, installs and maintains gardens for private homes and hotels and also develops botanical trails. Donna is the founder and first Director of the Botanical Garden of the Ozarks and is pursuing the development of a botanical garden in, and for, the Quepos area. [email protected],  2777-5149