Re: OT:Raised Beds
In a message dated 1/13/2003 9:57:52 AM Central Standard Time,
Autmirislvr@aol.com writes:
> Anyone with additional ideas? All remedies considered.
I make the following minimum assumptions: you are Southern, you are not
offended by receiving information you already know, and no one has a corner
on the thinking market.
Start by defining what end you ultimately wish to accomplish. One assumes you
want to create good garden soil, confine it in a manor that it will not
easily escape.
You already have surmised the existing soil is low in organic matter and
probably in sand. You need to address the question of how much organic matter
do I need to add? And, how much sand? Whether this is done all at once or a
little at a time effects only when the end is accomplished and the growth and
bloom production during that period of time.
An easy way to determine how much of each is needed is to take a
representative soil sample, place it in a gallon glass jar or other clear
glass container. Fill the jar 1/4 to 1/2 full of soil and the remainder with
water. The objective is to have a very low viscosity, homogeneous slurry.
Place the container in an undisturbed location until the contents settle and
the water becomes more or less clear. This takes from hours to days depending
on the specific gravity (weight for practical purposes) of the particles in
the soil. The sand layer actually settles out in minutes. The sediment in the
bottom will be in stratified layers. Some soil content will be floating on
the top but may ultimately settle. Remove the water without disturbing the
layers (siphon or turkey baster).
At this point, you may further dry the sediment in the oven below 150 degrees
F, or examine it as is. Determine percentage of the total sediment each
stratified layer represents using a tape measure. You can determine clay,
sand, composted organic matter and non-composted organic matter percentages
by examining the content of each of the stratified layers. If you dry the
mixture in the oven you have a permanent record of where you started. A piece
of paper with the same information is easier to store but harder to find. If
you desire, the oven dried layers may be crushed, remixed and used for a soil
test.
You now have a good soil profile and can determine how much of what you need
to add. The floating material is uncomposted organic matter. The top layer is
partially composted organic matter and the residual humus left over after
composting. I do not remember in what order the sand, silt and clay stratify
but it is obvious from observation. I think sand at the bottom, then silt
(clay and sand mixed), then clay. The top layer is the organic matter. Too,
if soil has a high gravel (big sand) content results can be skewed since the
voids in the bottom gravel layer will be filled with material from the next
layer up.
I find precious little information concerning ideal soils for irises. Too,
the "ideal" will depend on rainfall and frequency of same so it will vary
from area to area. But you might want to consider the following profile for a
good garden soil with some increase in the sand content as the end objective
in your beds since we get more rain than those less blessed parts of the
world. You want to wind up with roughly equal components of sand, silt, clay
and organic matter. You have to keep up with the approximate volume of what
you add.....more paper, more notes.
Most red clay soils are acidic in nature, rich in iron, and often rich in
plant nutrients. A soil test is mandatory. You might also want to consider
the higher above neutral you raise the pH, the lower the probability of soft
rot (add lime). I have successfully added soil amendments between iris rows
by shoveling a trench then filling with desired amendment (organic
matter/sand), then covering the trench. When bed gets redone a year or two
later, all is homoginzed with the tiller prior to replanting. I recall no ill
effects from doing so.
Your "tea" idea is interesting but I would suggest some caution and am not
saying do not try. I currently have some year old seedlings growing in a bed
prepared in stratified layers. A base layer of clay, topped with a layer of
course organic matter, and that topped with a layer of nutrient amended sand.
The seedlings are planted in the sand layer. None are doing well. All are
alive, none have rotted (rot experiment). Point being, ill effects may be due
to the high concentration or poorly composted organic matter near the root
zone though it could be from nitrogen depletion or a myriad of other factors.
It is doubtful that it is from "tea" production since the tea would be
draining down and away form the root system.
I am not familiar with the plastic product you anticipate using. Plastic
fencing product with which I am familiar are not as low maintenace/attractive
as promoted after a few years. They succumb to green algae growth and require
washing to remain attractive.
I'm thinkin' no self respecting Southerner would consider anything other than
treated southern yellow pine (staked with a ground driven 2x4 every few feet
if you want the board to stay plumb). The treated lumber lasts at least 30
years. You might have to paint instead of wash. To do otherwise, why that's
heresy! <g>
Good luck with an interesting project,
Bill Burleson 7a/b
A bird doesn't sing because it has an answer; it sings because it has a song.
- Maya Angelou
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