University of Vermont Extension
Department of Plant and Soil Science
GARDENING AND LIGHTNING
Dr. Leonard Perry, Extension
University of Vermont
As much as you may want to remain
outside gardening with thunderstorms in the distance, don’t! Thunderstorms often mean lightning, and
lightning can kill. There are some
important facts to know about lightning if you work outside in order to remain
There are about 25 million lightning
flashes in a year. About 66 people are
killed in an average year from lightning, about the same as killed from
tornadoes. Yet without the mass
destruction and killings of tornadoes, lighting often is not taken
seriously. Lightning can injure or kill
in three main ways—from a direct hit, from “step voltage” radiating through the
ground from a hit tree or pole, or from fires or fallen trees as a result of a
Thunderstorms produce lightning, as
well as the thunder you hear. Even if
you don’t see a thunderstorm, perhaps over the horizon or a hill, if you hear
one there is a good chance there may be lightning. You can hear thunder about 10 miles away,
which is how far away lightning can strike as well. Successive lighting strikes often are within
three miles, so if you see lighting this close take shelter immediately.
To tell how far away the lightning
is, count the number of seconds between when you first see the lightning, and
first hear the thunder. Then divide by
five. So, if the elapsed time is 15
seconds, the lightning is about 3 miles away.
This formula comes from the fact that light travels faster than sound,
in fact about one mile in five seconds.
In this example, you saw the lightning
almost instantly, yet it took 15 seconds for the thunder sound to reach you
from when it and the lightning took place.
Here are some tips to follow during
thunderstorms and lightning if you are gardening.
the first sound of thunder or notice of lightning, go indoors. If you’re in the middle of a project, and the
lightning is close, leave immediately.
You can pick up later. Stay
indoors for about 30 minutes after the last observed lightning and
thunder. Consider this a good time to
take a break, even read a garden magazine or book! But don’t go on the computer or telephone as
these can conduct a lightning strike to you.
Best is to unplug electronics and appliances. Keep away from windows, tempting as the storm
might be to watch. Don’t use this as the
time to take a bath or shower either.
you are caught outside away from buildings, seek shelter in a car, or low area
such as a ditch. AVOID water, high
ground, open spaces, metal objects such as tools, being on tractors and
machinery, canopies, small rain shelters, or trees.
you are caught unaware, and lightning strikes nearby, crouch down but do not
lie down. Put your feet together. Place hands over your ears to minimize any
hearing damage. Keep at least 15 feet
away from other people.
If a person is injured by lightning,
directly or indirectly, get to them and call 911 immediately. Make sure any victim has a medical
examination, as damage may not be apparent.
More tips on lightning safety, and helping victims, can be found in a
bulletin from University
of Maine Extension, or
from the National Weather Service (www.lightningsafety.noaa.gov).
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