Marin Home / GARDEN
Dirty Secrets
Top ways to improve your garden soil. BY KIER HOLMES
Gardeners know that dirt is and should be treated like, well, dirt. We
also know that dirt is not synonymous with soil, and it is typically what
winds up under fingernails and what’s tracked in by shoes — essentially
dead soil. Soil, on the other hand, is a living ecosystem and we should
give it the reverence it deserves because we know that healthy soil produces vigorous leaves, healthy crops and an abundance of flowers. With
that said, here are top ways to boost your soil and reap the benefits.
IN THE FIELD “I use cover crop SCM120, ordered from Peaceful Valley Garden Supply in
Grass Valley,” says Allison Krivoruchko, a Marin Master Gardener and soil expert. “I plant
it in October and then cut it down at the end of March when the cover crop flowers are 50
percent in bloom, then put compost over it for a month before planting.” She also recommends using compost tea from Harmony Farms once a month during the growing season.
THE GOAL Strive to build up the existing
soil so that air, water and nutrients are easily
accessed by plant roots. Adding organic matter
to the mix is a superior way to give roots more
opportunity to penetrate soil. Test Time Learn
what’s in your soil and you’ll discover whether
organic material or nutrients/fertilizers should
be added or if the pH should be altered (you
can purchase a soil test kit at your local garden
store). It is important to test before starting a
new garden or if your garden’s health is declining. Much About Mulch Enrich your soil with a
layer of mulch to help conserve moisture, add
organic matter and suppress weeds. Got You
Covered Consider planting a cover crop that
includes vetch, clover and fava beans over
bare winter soil, then cut it down and chop it up
directly into the soil. This process loosens the
soil, transfers the nitrogen from the atmosphere
into the soil and adds significant organic matter.
Cover crops also protect soil and control weeds
in the off-season. Like Us Soil has the same basic
needs as we do: food, water, air and shelter. But
unlike us, soil always needs nitrogen because
nitrogen feeds plants and soil organisms. Good
sources of nitrogen are manures and green grass
clippings added as amendments. Do’s and Don’ts
Avoid digging, walking on or rototilling wet
soil, especially clay, because it compacts the
soil structure and squeezes the air out, leaving
limited room for root growth or for organisms
to breathe. Worm Business Instead of breaking
your back digging, add worms and let them do
the hard work while you are sheet mulching (
putting a layer of material like cardboard over an
area to kill weeds before planting). Worms leave
nutrient-dense manure castings and help aerate
the soil. The Basics For most purposes, add a
complete organic fertilizer and apply as recommended. Organic (not synthetic) is best because
the nutrients and minerals occur naturally.