By Mike Isbell
University of Georgia
Some things you just know are sweet — ice cream, apple pie,
clean babies. Farmers and gardeners sometimes refer to their soil
as sweet and even speak of sweetening it.
How sweet is the soil around your home? If you don’t know, you
need to find out. But don’t go out and taste a spoonful — have
it tested.
“Sweet” soil is simply soil that’s only slightly acid. The pH is
probably the most important thing to know about your soil. It
shows how acid your soil is. The lower the number, the more acid
the soil.
So what?
It’s important to know your soil’s pH because plants have a
certain pH level at which the nutrients in the soil are most
available to them. If the pH of your soil is wrong, the plants
could be starving for those nutrients, even if they’re right
there in the soil.
So what’s the best pH? It all depends on the plants you’re trying
to grow. Take centipede grass, for example. The pH for good
centipede growth is 5.5, but it will tolerate a pH below 5. Other
grasses need a higher pH, somewhere around 6.
If you find you have a low pH, add lime. Fortunately, that may be
the cheapest thing you soil needs.
Whatever plants you have, whether they’re fruit trees, shrubs,
vegetables, forages or turf, you can’t know if you need to lime,
or how much lime to add, if you don’t know your soil’s pH.
You need to test it
Take a soil sample that’s representative of the area. To do that,
get samples from 10 to 15 spots from 3 to 4 inches deep for lawns
(8 to 12 inches for orchards). Mix the samples for each kind of
plant. From the mixture, bring about a pint sample to your
county office of the University of Georgia Extension Service.
They’ll have your test results in about a week.
Fall is a good time to add lime, because winter rains will help
activate the lime in the soil. But the best time to add lime is
whenever you need it.
That may be all the “sweetener” you need.
(Mike Isbell is the Heard County Extension Coordinator with
the University of Georgia College of Agricultural and
Environmental Sciences.)
