Looking for something else?
As you may have observed from your gardening experiences plants
can be fussy things. The right location, amount of sunlight and
101 other factors influence your plant's growing ability. One
factor which is very beneficial in understanding before putting
that new plant into the earth is soil pH.
What is Soil pH?
Let's get all scientific for a moment and learn what pH is. In
chemistry pH is a measure of how acidic or alkaline a solution
is. Okay chemistry lesson over. Basically soil pH is a measure
of how acidic or alkaline your soil is. Soil pH is measured on
a scale of 1 to 14. If your soil has a pH value of less than 7
then you have acidic soil. On the other hand if your soil has a
pH value of greater than 7 then you have alkaline soil. A pH
value of 7 is neutral, meaning you have neither acidic or
alkaline soil.
The Effect of Soil pH on Plants
Knowing the pH value of your soil before planting is very
important as it has a direct influence on the health of the
plant. Each plant has its own recommended soil pH value range.
The reason for this is that soil pH effects the availability of
nutrients within the soil and plants have different nutrient
needs. For example the nutrient nitrogen, a very important
plant nutrient, is readily available in soil when the pH value
is above 5.5. Similarily the nutrient phosphorous is available
when the pH value is between 6 and 7. If a plant is placed into
the wrong kind of soil it will be lacking in nutrients that it
needs which will promote disease. In general the best pH value
range for soil is approximately 6 or 7 as this is the range in
which most nutrients can be readily available.
Finding Out pH of Soil
Finding out the pH of soil is usually a trivial matter and the
kits to do so should be available at most good garden centres.
Usually a pH testing kit will include a small container / test
tube, testing solution and a color chart. A sample of soil is
taken from your garden, placed into the container / test tube
and a few drops of testing solution are added. The container is
then shaken and left for a certain period of time. The color of
the sample in the container is then compared against the color
chart to determine the pH value of the soil. Note that if you
want to determine the soil pH of an large area it may be a good
idea to take soil samples from many different locations, combine
the samples and then perform the test on the combined sample.
A quick way to find out the pH of an area is to look to see if
there are any house hydrangeas (Hydrangea macrophylla) already
growing in the area. If so observe the color of its flowers. A
soil pH of 6 or below will produce blue flowers while a soil pH
of 6.8 or higher will produce pink flowers.
How to Make Soil More Alkaline (Increase pH)
If your soil is acidic or slightly acidic you can take steps to
make it more alkaline to accommodate the plants you want to put
there. You can make your soil more alkaline (increase its pH
value) by adding a form of lime. Lime is a compound of calcium
or calcium and magnesium. It is usually applied in the form of
ground agricultural limestone, burnt lime or hydrated lime
(slaked lime). The smaller the limestone particles then the
quicker your soil will become more alkaline. For this reason
hydrated lime will offer the quickest performance because it is
slightly soluble in water so it can permeate the soil quicker
and reduce acidity faster.
Increasing the pH of your soil is not an overnight process and
it is best to allow 2-3 months to allow the lime to neutralize
the acidity of the soil acidity.
How to Make Soil More Acidic (Decrease pH)
Some ornamental plants and fruit plants like blueberries
require an acidic soil. To make your soil more acidic (decrease
its pH value) you can use either aluminium sulphate or sulphur.
Aluminium sulphate is the quickest acting as it will increase
the acidity as soon as it dissolves into the soil. The
downsides are though that its effects can be short term and it
is possible to over-apply it.
The more recommended but slower way to increase your soil pH is
to use sulphur. Sulphur converts to sulphuric acid with the help
of bacteria in the soil but this takes time depending on factors
like the presence of bacteria, texture of the soil and moisture
levels. This could take months if conditions are not ideal.
Conclusion
Remember to always take into account soil pH when deciding what
to plant in your soil. If you do not know what the pH of your
soil is then test your soil and if needs be take steps
mentioned earlier to change the pH value over time. Best of
luck!
Francis Kilkelly runs a great gardening
community at
www.gardenstew.com containing forums and
gardening blogs (
www.gardenstew.com/blogs.php).
Original Article Location:
http://www.gardenstew.com/blog/e3-9-soil-ph-and-its-effect-on-your-garden.html
©2005 Francis Kilkelly. All rights reserved.
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