Summer!
Bales of peat become weighty issue for the
Under-gardener
What is the purpose of peat moss? My wife adds it to
everything driving the non-gardener laborer (me) nuts. My inquiry,
"Why do we do this?" results in the definitive, "Because it's good
for the soil." - S -
Soil does support plants but plants also support soil. The
answer to your question is a lesson in soil science.
Step one in soil formation is weathering of rock. We name the
fragmented minerals by their size -- from largest to smallest
they're sand, silt or clay. Still, you wouldn't recognize them as
soil, yet.
Few plants can grow in thin, raw mineral matter. Some alpine
species do grow in "scree", a mix of these shifting particles plus
loose rock. The plants use solar power to combine water-soluble
minerals at their roots, carbon from air and hydrogen, oxygen and
nitrogen from rain to make complex carbon compounds -- organic
matter. When the plants die or shed parts, the captured minerals
return to the soil along with "new" carbon, hydrogen and
nitrogen.
Fungi, insects and other soil-dwellers move in now. They feed on
carbon and nitrogen, converting dead plant matter to humus and then
adding to the stew their excrement and a humus residue called
microbial glue. These are sticky in both atomically electric and
Elmer's glue fashion, pasting mineral particles together in crumbs.
Soil crumbs provide places for water to linger where it could not
before. A wider range of plant species grows in this richer,
moister mix.
Succeeding plants use fresh ions from the mineral part of soil
but also reuse nitrogen and other elements from decomposing organic
matter. Over eons, continually crumbling base rock and new organic
matter make the soil deeper but the organic matter in it never
stops breaking down and being reused. If plants continue to grow
there but something blocks the return of organic matter, carbon and
nitrogen levels decline and the soil's crumby structure breaks
down.
When we prepare to plant we remove weeds, roots, turf and other
organic matter. As we garden we block our plants' complete return
to the soil by weeding, deadheading, harvesting, mowing, and
pruning. Your wife chooses to replace this lost organic matter in
the form of peat -- plant parts that have been partially decayed
and then preserved in bogs.
So keep adding peat if you want that healthy loam to stay
healthy. Or if you wonder about the wisdom and sustainability of
importing organic matter when there is plenty right here being
carted away to landfills and compost sites, you can compost your
yard waste and replenish the soil with that form of humus.
Composted animal manures, raw fall leaves, shredded paper and grass
clippings work, too -- anything with carbon compounds in it.
(More discussion developing right now about using peat, at our
Forum. Go see.)
I just bought a house with a small yard and want to have
a really nice landscape. I've been shocked by the landscaping
estimates and think I'll do the work myself. Any suggestions where
to start or how to proceed? - T. G. -
Don't rush -- landscapes last a long time when they're well
planned and planted. Loosen the soil and add organic matter. Talk
to gardeners in the area about what works and what doesn't. Look at
mature landscapes in yards similar to yours and learn the names of
plants you like.
Then sit down with paper, pencil and a book (that's the purpose
Janet had in mind when she wrote Designing Your Gardens and
Landscapes), or take a class where you can develop the design
as assignments that other students and the instructor can comment
on.
Timely Tip
Hedge getting thin at the bottom? The
underlying cause is not lack of fertilizer or disease but shade. If
upper limbs overhang by even an inch, that's less light for the
base. To keep lower foliage on evergreen shrubs or restore it on
deciduous plants, cut the hedge so it's narrower at the top than
the bottom. Thin upper branches to open tiny windows that can be
lifesavers for leaves below.
Green thumbs up
To late season garden walks. We learn from May,
June and July tours but also need late summer and fall examples as
we pursue continuous color and interest in our gardens and
landscapes.
Green thumbs down
To those who whine about badly mowed lawn yet do nothing more
productive than pester the family mowing crew about dull mower
blades. Why not surprise them by taking the blade to be sharpened
or buying and learning to install a replacement blade?