DATE:    03/02/04 
WRITER:  Chuck Burgess, 1-888-656-9988
EDITOR:  Susan Bedingfield, (864) 656-3876

When looking toward spring planting -
don't neglect that soil test

			By Chuck Burgess, 
			Information Specialist,
		Clemson Extension Home & Garden Information Center

	CLEMSON - The most common gardening questions asked are: "How 
much lime and how much fertilizer should I add to my soil?"  
	There are general guidelines; however the most accurate way to 
answer these questions is through a soil test.
	A soil test is important for two main reasons -- the level of 
nutrients in the soil and the soil pH.
	There are 14 soil nutrients required for plant growth. A soil 
test takes the guesswork out of fertilization. You only add elements to 
the soil the plant needs, avoiding excessive fertilization.  Adding 
nutrients to the soil when they are already present in ample amounts is 
not only a waste of time and money, but is also environmentally 
hazardous.  
	The term pH is a measure of the hydrogen ions in the soil, 
which causes the soil to be either acidic or basic.  On a scale of zero
to 14, values below seven are acidic and values above seven are basic.
	The major impact soil pH has on plant growth is related to 
nutrient availability.  As pH changes, nutrients become either less or 
more available for uptake by roots.  At a low pH, manganese becomes 
more available, but calcium becomes less available.
	The key  -- all plants have a pH range at which they grow best, 
and a soil test will tell you how to get your soil pH into that range. 
 	Azaleas and rhododendrons prefer a pH of 5.0 to 5.5. 
Vegetables, turfgrasses and most ornamental plants prefer a pH of 5.8 
to 6.5.  It is in this range that the nutrients they require are most 
readily available. 
	In addition, pH also helps to keep soil healthy.  Certain 
bacteria that decompose soil organic matter are hindered in strongly 
acid soils.
	For optimum soil management, soil should be tested every two to 
three years because pH changes very slowly.  This schedule gives you 
enough time to add soil amendments and nudge it in the right direction, 
keeping the soil pH in the optimum range.
	The soil should be tested prior to planting trees, shrubs, 
grasses and flowers.  A five-dollar soil test prior to planting is a 
sound investment considering the cost and work involved in purchasing 
and planting plants.
	Prior to establishing a new lawn, a soil test is very 
important.  Before seeding or sodding, you have the opportunity to make 
amendments to the soil and till them into the root zone. This puts 
nutrients to the roots, and if lime is needed, it will work more 
quickly. 
	In other instances, you may want to test soil when you suspect 
that an improper pH is adversely affecting the growth of the plant.  
Azaleas and blueberries grow best in acidic soils.  Their leaves may 
yellow when the soil pH is too high because they are not able to take 
up adequate iron. 
	Soil submitted for sampling should represent the planting area.
If the entire lawn area appears to be a uniform soil type, samples 
should be taken from several locations and mixed together.  If the soil 
in some areas appears very different, keep the samples from these areas
separate and submit more than one sample.
	Likewise, groupings of plants may require their own soil test. 
 Separate soil samples from azalea plantings and vegetable gardens.  
These plants have different nutritional requirements and pH 
preferences.
	In a cultivated area, remove soil for sampling from six to 
eight inches deep.  In a turf area, remove soil from two to four inches 
deep.  
	Take a small amount from several locations within the bed or 
area, so the resulting mix is representative.  Mix it together in a 
clean, plastic bucket and take at least a pint to your local extension 
office.  The fee is $5.
	As spring approaches and there are plants in your landscape 
that struggled last season with yellowing leaves, poor blooming or slow 
growth, consider a soil test.  The results will tell you how much to 
fertilize, when to fertilize and if the pH needs adjusting. 
	For more information on fertilizing and soil testing, visit 
Clemson's Home and Garden Information Center website at 
www.hgic.clemson.edu.
	******************************************
	For answers to your gardening, pest and food safety questions, 
	visit the Clemson Extension Home & Garden Information Center 
	website at http://hgic.clemson.edu, call us toll-free at 
	1-888-656-9988, or write to PSA Media Relations, 120 Lehotsky 
	Hall, Clemson University, Clemson, S.C. 29634-0129.
				END