Understanding your existing soil is key to
creating a successful rain garden.
We will amend your existing soil as needed
to create a mix of soil particle size that
will allow for appropriate drainage while
also supporting healthy plant and soil life.
A ribbon test is a simple test, but does take
practice to learn how different soil types
behave.
We use a ribbon test to access our rain garden
site and to determine if your soil is, generally
speaking; sand, sandy loam, clay loam or clay.
This is important to know as water more easily
migrates into and through sandy soils because
of the larger particle sizes and less resistance
to infiltration.
Water infiltrates more slowly in clay soils.
To gain an understanding of your soils texture,
perform the ribbon test:
Take a sample of soil from the bottom of your
percolation hole.
Take a small handful of that soil, add small
amounts of water.
Make sure you don’t over water your sample,
if you squeeze the soil and water comes out,
the soil is too saturated for a ribbon test.
Continue to squeeze and shake until no more
water comes out.
Make sure to remove any material such as rocks,
plants or sticks from your sample.
You will also want to work the soil so that
it is not stuck in clumps.
Next, Try to make a ball & throw the ball
up and down in your hand, a few inches will
do, if the ball crumbles in your hand, you
have high sand content in your soil.
Notice how the soil feels in your hand, sand
will feel grainy.
If you are able to make a ball, next try to
maneuver the ball into a ribbon by pressing
the soil gently between your thumb and forefinger.
Try to make a thin ribbon as long as possible,
before the ribbon breaks.
Notice the texture of the ribbon.
If it feels gritty, and you are only able
to form a ribbon less than half an inch in
length, then you have sandy loam.
If your ribbon feels slightly sticky and smooth,
and your are able to form a ribbon less than
an inch in length, but more than half an inch,
then you have Clay Loam.
If your ribbon feels sticky and smooth, and
you are able to form a ribbon longer than
an inch in length then you have clay.
Each of these soils requires recommended amendments
to function as soil medium in your rain garden.
For example, If you have high clay content
in your soils, you will not want to add sand
as a soil amendment in your rain garden.
Sand plus clay equals clogging and will not
be good for rain garden conditions.
Instead, if you have high clay content, and
still pass the recommended percolation test
of under 24 hours, then you will want to add
compost to your rain garden cell.
