Watering Your Plants

Properly Watering Your Gardens Will Ensure the Health and Vigor of Your Plants

It may seem simple, and to be sure just giving your plants water when they need it is most important, but there are many things you need to pay attention to to properly water the gardens.  First and foremost, know the needs of your plants.  But you also need to know something about your soil, micro-climates, and pay attention to the weather.

Your Soil

Water is available to the roots of your plants from the air pockets between the soil particles.  If you have clay soil, the pockets are very small and held pretty tightly in those pockets, resisting gravity that pulls the water out.  But those small pockets holding tight can also make it more difficult for roots to draw the water.  Clay conditions creates the difficult situation of moist soil, but the plants may not be able to easily access it.  But over saturating the soil will only make matters worse.  Clay soil will need little supplemental watering, wait for the soil to become quite dry.  Sandy soil will need more supplemental watering than clay.

Focus on the Roots

Since plants take in water through the roots, make sure you are soaking the soil deep enough to reach the entire root zone of the plants.  Soaking the soil deeply and less often is more beneficial to your plants than light frequent watering.  It will encourage the roots to grow deep, strong, branching roots rather than spreading across the surface waiting for frequent sprinkles.  A plant with that type of root system will wilt quickly if a watering is missed.  Most annuals will need a soaking to 6 inches.  Perennials and most shrubs need the soil soaked up to 12 inches.  Trees need a large area soaked at least 12 inches.  Soaking the soil 6 to 12 inches could take hours, but it will stay moist for a good long time.  Spraying water over the foliage has little or no benefit other than promoting disease.  In containers and hanging baskets, much of the water you sprinkle in will initially run between the root ball and container, and out the drainage holes.  Be sure to slow soak containers until all the soil becomes moist.  Reduce evaporation of moisture from the soil with mulch several inches deep.  Containers can be mulched with sphagnum moss.

When to Water Plants

Every plant has individual water needs, so when you purchase plants pay attention to the care instructions.  When planning a garden or landscaping, it is helpful to choose plants with similar needs so care is simplified for a group or area.  And different planting locations in your landscape will have different conditions (micro-climates).  A north facing area may be quite shady or quite windy, south facing may be very hot and sunny, foundation corners may be well protected from wind.  Pay attention to the effects of location.

Wilting is NOT a good indicator of a need for water.  Plants may wilt when the need water AND when they are over watered.  Check the soil instead.  Poke your finger deep into the soil to see if there is moisture down in the root zone.  Then water deep and thoroughly only if needed.

Both hot and windy weather will dry the soil out rather quickly.  The surface will dry quickly, but there may still be plenty of moisture deeper.  Again, poke your finger into the soil 4 to 6 inches.  Wait to water until it begins to dry out deep.  Most plants do not need consistently moist soil, but some do!  Be sure you know what your plants need.

Morning is the best time to water plants.  Moisture left on the foliage will be able to dry quickly in the sun, minimizing the opportunity for disease to develop.  If the weather is not too hot, early afternoon will give your plants plenty of time to dry.  On very hot days the evaporation can be very rapid and a good deal of water will be lost before it every gets to your soil.  You may notice certain plants wilt under hot afternoon sun.  It is tempting to water right away, but check your soil, it could be plenty wet and then you will oversaturate your soil.  As soon as the sun begins to go down you will see the plants perk back up.  Consider that the plants should not be planted where they are exposed to hot afternoon sun.  If the situation is caused by temporary extreme heat you could erect a temporary screen or put up a beach umbrella for a few days to protect the plants.  If you just can’t stand it, go ahead and mist the plant with cool water from a spray bottle.  Your plants will get temporary relief without adding water to the soil.

Water Efficiently

Take advantage of rainfall of course!  If you get an inch of rain in a week you do not need to water anything.  When supplemental water is necessary, water slow and deep.  One inch of water will soak soil down to about 6 inches.  Sandy soil may need an inch every 5 days, but clay soil may only need an inch every 10 days.  Use a rain gage to see how long it takes your sprinkler to put down and inch.  For hand watering use 5 gallons per square yard of garden.

Apply water slowly to prevent runoff.  And water doesn’t really soak sideways, only down.  If you are putting down a very large amount of water in one spot, it may seem to soak sideways, but it is just flowing across the surface because it cannot soak in fast enough.  This will cause mulch and soil to washout and runoff.

Watering Devices

Without question, the best device for watering gardens is a soaker or drip hose.  Water slowly seeps from the hose laid directly on the soil surface.  No moisture is lost to evaporation.  No moisture is left on the foliage to promote development of disease. The water seeps slow and deep to the roots.  A soaker hose can be snaked through the garden and around plants, very efficiently watering a large area.  When you first use a soaker hose, periodically poke your finger into the soil to see how deep the water is soaking.  This will help you determine how long to run the hose to get 6 yo 12 inches deep.

Lawn sprinklers are fine for the lawn, but there are a great variety of devices.  Oscillating sprinklers are very popular, but more water than you might like to imagine never even reaches the ground.  Water begins to evaporate as soon as it leaves the sprinkler and evaporates all the way up and continues to evaporate on the way down.  The center point of the spray then loses the most (this is where the water sprays the highest) causing uneven watering.  As much as 30 percent of your water is lost.  Wind will accelerate evaporation as well as cause further uneven watering.

Impulse sprinklers minimize evaporation loss by keeping the arc of water low to the ground.  Throwing the water low and flat also minimizes the effects of wind.  An impulse sprinkler generally allows quite a bit of adjustment for coverage so you can adjust to odd shapes in your lawn.  This is the same delivery means as most automatic in-ground sprinkler systems.

For soaking trees or large shrubs you can use lawn sprinklers or soaker hoses.  But for a good soak in extended dry periods you can just lay down an open hose running at a trickle.  Move the hose end every hour or so all around the root zone.  Or use one of those tiny spot sprinklers that sprays water in a fountain.  Run the water low to create a small fountain spray.  This will slow soak a little larger area than a trickling hose with minimal evaporation.  Move the sprinkler every hour or so all around the root zone.

Funny how the same old rules keep popping up!  Know your plants, know your soil, know your micro-climates, and know your weather/growing zone.