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Soil moisture more important than fertilizer
I built significant gardens in my back yard with new top
soil. Thinking that the soil must be good, as I paid a lot of money
for it, I did little to fertilize. All my expensive plantings did
not prosper. I have been fertilizing with Miracle Gro, peat moss
and grinding up leaves and spading them under, with marginal
I've read articles about plants needing acid soil. Last
season I sprayed with Miracid and got much better
Is there a regimen I can follow to turn my soil more
C.B., on the Internet
You're barking up the wrong tree. Some plant species prefer acid
soil -- low pH -- but most landscape plants grow quite well in any
loose, well-drained soil that is "circumneutral" -- neutral or
within a point either way of neutral on that pH scale. Great Lakes
soils rarely miss that mark, even when stripped from one spot and
moved to another.
Topsoil, by the way, is not priced for fertility but for the
cost of moving it around.
When it comes to fertilizer, plants given the right amount of
sun and water grow without it. Well-lit, well-watered plants would
have grown passably well without fertilizing.
I suspect your problems are related to two conditions which are
far more universal than pH in their effect on plants. How are the
sunlight and water in your garden?
Sun is a plant's sole energy source. Plants use solar energy to
turn air and water into carbohydrates -- sugars and starches made
from carbon, hydrogen and oxygen molecules. Those fuel all other
life processes in the plant. Fertilizer is like vitamins, not food,
and cannot compensate a plant for too little energy.
Check your garden for hours of sun during the growing season,
then check your plants in a garden encyclopedia to see if they are
getting the light they need. Full sun plants need six or more hours
of shadowless sunlight every day. Half sun and half shade species
must have four to six hours of sun. Shade plants require at least
two hours of sun each day. Move any that aren't getting sufficient
Water is probably another key to this puzzle. Across-the-board
poor growth, pale foliage and root trouble often stem from too
little or too much water.
Given too little water, plants can't fill up their cells or get
hydrogen to make carbohydrates.
We had copious rain last year, so much more than usual that many
plants competing with trees for their water grew the best their
gardeners had ever seen. Are your beds under or near trees? Perhaps
it wasn't fertilizer but rain that made the difference last
If water-guzzling trees aren't the problem, what about slow
drainage? When there's too much water, all the air is pushed out of
the soil. This kills roots, since they need atmospheric oxygen to
live. Once roots die, the foliage receives less water, wilts and
starves as if in a drought.
Drainage is not puddles on the surface in this case but excess
water <i>in the soil</i>, in spaces where air should
be. Excess water should drop quickly out of the top eighteen inches
of soil or roots will die.
Loose soil piled on top of hard-packed earth tends to drain
poorly. Water moves quickly through the loose soil but puddles
above the denser layer. The sogginess of this "perched water table"
may be invisible to us but is devastating to plants if it occurs
within that eighteen inch root zone.
Do a drainage test to see how long it takes excess water to fall
out of your soil. Dig a hole eighteen inches deep and fill it with
water. Let that drain and then fill it again. Time the second
draining. If all the water is not gone from that hole within a day,
install a drain tile to remove it more quickly.
As for fertilizer, one in liquid form may have dramatic effect
on plants which have lost roots in dry or overly wet soil. Products
such as Miracid sprayed on the foliage can bypass a damaged root
system, go directly into the leaves and may cause them to green up
immediately. The plant can look better even though underlying
problems still exist.
Use the new moon to advantage. Moon-phase
gardening lore tells us that the very best time to weed or destroy
pests in a garden is during those days on either side of the new
moon -- that's today and tomorrow. If you had a weedy area last
year, rest assured those weeds are there still. Why not tackle them
Green thumbs up: to leaving fallen leaves on
most beds, even several inches deep. Rake lightly to break up
matted layers but don't remove them. Leaves not only suppress weed
seedlings but will be broken down into natural fertilizer by worms
and microbes as the soil warms.
Green thumbs down: to slugs, now emerging. In
beds that had significant slug problems, do remove all leaf litter
now. Set out slug poison or traps for several weeks. With little
else to eat and no leaf litter to hide in, slugs take baits or fall
for traps and you're rid of them before they do much damage.
First published 3/24/01
This issue Sponsored by: Cindy E
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