Keys to Proper Landscape and Garden Watering
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By Dr. Douglas F. Welsh, Landscape Horticulturist
Texas A&M University, College Station, Texas
n a few months we will be in the midst of another hot Texas summer. Properly watering plants during the summer tends to be one of the most confusing and misunderstood gardening chores. Often, ardent gardeners do not recognize inadequate watering until it is too late and plants are badly damaged or dead.
“How often should I water?” and “How much should I apply?” are a couple of the most-often asked questions from gardeners. Since water is both essential for healthy plant growth and often costly to apply in quantity during the summer, it is important to get it to the plant’s roots efficiently and keep it there.
The following are several suggestions for easier and more
effective watering. These techniques apply to all gardening,
from shade and fruit trees and vegetable gardens to
lawns and house plants.
For plants to thrive during the
upcoming summer months,
they will need plenty of water,
but equally important is
properly applying the much
- Never water strictly by the calendar. We don’t drink
water 'every ten minutes' or 'every hour', so why should
plants be watered 'every two days' or 'once a week'?
Instead, learn to recognize dry plants and soil and use
these as your tip-off for watering. Too many factors
determine how fast a soil dries for us to put watering on a
- When the plants are dry, water thoroughly. Water
lawns so that the soil will be wet several inches down, to
encourage deep rooting and drought tolerance. One of the
worst mistakes people make in their gardens is trying to
'sprinkle' them each day by using their thumb and the end
of a running hose. Most gardeners just don’t have the
patience to stand in one spot long enough for deep water
Water trees by taking the sprinkler off the end of the hose
and letting water run slowly for several hours out under
the drip line (not near the trunk). Be sure that runoff does
- Most plants should be watered in the morning. Evening
watering increases the likelihood of disease invasion, as
the majority of diseases develop most rapidly in cool,
- While watering your lawn, try to keep water off
the leaves of trees and shrubs as much as possible.
This is especially important for such plants as
crape myrtle and roses, which are troubled by
leaf diseases which spread rapidly on wet
- Symptoms for plants which have been kept too
wet are about the same as for those kept too dry.
Roots in waterlogged soils die and do not take up
water, so plants wilt and turn yellow. Try not to water
a drowning plant!
- Organic matter, such as shredded pine bark and
composted manure can increase water absorption when
they are worked into our native soil.
To keep moisture in the soil, use a thick mulch, such as
shredded pine bark, grass clippings or tree leaves. In
addition to reducing evaporation, mulches also keep the
soil cooler and make weed pulling much easier.
- Be especially careful to keep newly planted trees and
shrubs well watered. Their developing root systems are
sensitive to under- and over-watering. But again, don’t
- Always soak chemical fertilizers into the soil immediately
after application. These materials are excellent
sources of plant foods, but they are also salts, and can pull
water out of plant tissues, resulting in burn, unless they are
watered into the soil.
- Gardeners often wonder what type of sprinkler is best.
Generally speaking, most do a satisfactory job of making
an even application. However the most efficient and
effective type is the impact sprinkler (the kind used on golf
courses and athletic fields).