Healthy plants and good fruit are no accident. It all starts
with good soil. As the old saying goes "plant a $50 plant in
$100 hole." How do you know if you have good soil? Making good
soil is more of an art than a science. However, understanding
the components of soil gives you a good place to start.
Soil structure - Soil is classified in
three basic particle sizes- sand, silt, and clay. To test the
particle content is a simple as grabbing a handful of wet soil
and squeezing it. If the ball falls apart it is sandy. If the
ball holds together but cracks it is silty. If the ball formed
by squeezing retains it's shape then it is clay. The ideal soil
structure is somewhere in the middle between clay and sand.
Sand in the soil keeps it loose so that roots make good
progress in their quest for nutrients. It also drains quickly
and prevents root rots. Clay in the soil helps to retain the
moisture but has a tendency to keep roots bound up. Too much
clay will also affect the absorption of certain minerals. The
best way to balance the soil structure and provide nutrients is
to condition the soil with compost.
Soil nutrients and pH - A soil test is
is a valuable tool to determine the available nutrients in the
soil. This can be done with a home test kit available at most
garden centers, or a soil sample can be sent to to your local
university or extension service for a nominal fee. The
advantage to submitting your soil sample is that you will
receive not only the results of the test, but also measures to
correct any problems.
The three primary nutrients plants need are nitrogen,
phosphorus, and potassium. Nitrogen is needed for stems and
leaves; phosphorus for roots and fruits; potassium for cell
structure and as a catalyst for phosphorus. The plants
themselves can serve as a litmus test to deficiency in these
three primary nutrients.
Yellowing leaves shows a lack of nitrogen. Dark green leaves
with purplish cast may be deficient in potassium. Sickly plants
slow to produce fruit which have scorched leaves could
indicate the soil is deficient in potassium. If you are new to
gardening, observe the performance of your plants but back it
up with a soil test before correcting deficiencies.
Soil pH is the second critical factor in plant health. The
pH scale refers to the acidity or alkalinity of the soil, and
is measured in units on a scale of 0 to 14 with 7.0 being
neutral. Different plants prefer different pH ranges for
optimal growth. The correct pH in the soil will assure the
maximum absorption of nutrients for the plant. If you have
plenty of N-P-K in your soil, but the pH is off, you could
misinterpret your plants needs and damage your plants by over
fertilizing. PH can only be measured with a soil test.