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| Deep mulching produces a bounteous harvest! |
Here in the Sharing Gardens we practice a style of
gardening known as "deep mulching". Just as it is rare to find bare soil
in nature, in our gardens you won't find much exposed soil either. We
use the materials that are easily available in our area (grass
clippings, leaves and spoiled hay) and let nature do the work of
increasing the garden's fertility. People who raise livestock such as
cows, goats, chickens and rabbits know how important it is to give
appropriate food, water and shelter to keep their animals healthy. In
turn, these animals produce by-products that are beneficial to the
people who care for them, not the least of which are the nutrient-rich
manures used as the basis for many commercial fertilizers. In the
Sharing Gardens, we tend to "livestock" on a slightly smaller scale.
Worms, fungi, beneficial insects and bacteria are the
micro-livestock we
care for with our heavy mulching. They, in turn, provide a natural
balancing of the soil along with castings and other "waste products"
that feed the plants' rootlets right where they need it most.
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| Mulching feeds your "micro-livestock" |
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In these first years of establishing new
garden sites in Alpine and Monroe, we also have used a high-quality organic
fertilizer, our own worm-castings compost, and rabbit and llama-doo
applied judiciously to the plants that need a boost.
But we don't apply
any single concentrates of nutrients such as lime or gypsum as we have
found through years of gardening experience that a garden's soil can get
seriously out of balance through the application of these concentrates. (
Note: As of 2018, we no longer use any manures from livestock and have weaned ourselves down to a few gallons of fish-emulsion and 3 pounds - or less- of commercial fertilizers per year!)
A summary of the benefits of "deep-mulching":
- Keeps
moisture in (less watering). Though when you water, you must water long
and deep to be sure the water penetrates down through the mulch and
into the soil. In our Monroe garden, we have gone over two weeks without
watering in the heat of August but we watered each section of the
garden for over two hours at the beginning of those two weeks. When
you're first planting a bed - with seeds or transplants, you need to
water more often till the plants are established. To check if you need
to water, lift mulch in the paths and check for moisture level in the
soil. You can often see red worms and tiny rootlets extending from the
plants growing in the beds.
- Keeps weeds down.
- Balances your soil-nutrients (your "micro-livestock" keep things balanced without you having to figure it all out.)
- Moderates day/night temperature fluctuations in the soil.
- Adds organic matter to keep soil from becoming too sandy or clay-bound.
- It's very comfortable to sit or kneel on as you cultivate and
harvest your plants. (We had a photographer come to our gardens once and
said it was "the most comfortable" garden she'd ever been in!)
What materials make good mulch?
It is best to choose materials that are readily available in your local
area. Urban gardeners may find that leaves and grass clippings are
easiest to come by.
We love leaves! Many cities will actually dump a load of
leaves for personal use if you have an adequate drop-site. Do be aware that you can't be 100% sure of the
kind of leaves you're getting. There is also likely to be
some
residue from oil and other materials from motorized vehicles (though
probably not enough to be very concerned about). You'll need to be sure
and use good gloves in distributing city-leaf piles as its possible that
broken bottles or other sharp trash could be mixed in.
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| Leaves we collected from Alpine Park |
Hand-raking
leaves is our favorite method for gathering this valuable resource.
Leaf-raking gives you a great work-out without being too strenuous (we
call it "rakey" (reiki) therapy -ha.) You can use tarps to haul the
leaves to
your garden, or bag them in leaf-bags. We have established relationships
with one neighbor where we help rake and load his leaves and he brings
them to us with his dump-trailer. We have another neighbor who lets us
leave a large trailer with high-sides on his property while he loads it
for us for later pick-up. You know how the saying goes, "One mans
burn-pile is another man's compost!" (or something like that!)
In
some years we have applied the leaves on dormant beds in the fall so
they can decompose in time for spring planting. Other times we have
stored leaves
in rings we crafted from fencing, or just made a deep pile and tarped it
for the winter. This latter option produced very rich, yummy,
decomposed leaf compost by the following spring. We have also layered
leaves and fresh grass-clippings in these rings which also makes a great
mulch.
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| We love maple leaves! |
What kinds of leaves are best: Generally speaking,
the thinner the leaf,
the easier it breaks down. Maple is our favorite. Fruit-tree leaves are also great. Oak takes a long time
to break down but otherwise works fine.
Don't ever use walnut leaves as they have a natural substance in them that is poisonous to plants and will destroy your garden's fertility.
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| Maple leaves make excellent mulch |
Hay! Hay! Hay! If you live in, or near the country,
straw and spoiled hay
make a great mulch. Straw is the baled stalks from grain crops (wheat,
oats, barley) after the grain has been harvested on top -- typically
used for bedding. Straw has a lower nutrient content than hay bust also,
usually fewer seed (so not so many weeds to deal with later-on). Hay is
typically the stems of grasses after their seed-heads have been
harvested.
Many farmers have hay from previous seasons that
has become wet or moldy or otherwise unsuitable to feed to their
livestock. They will usually be glad to have you haul it away for free,
or very little per bale. If you don't have a trailer, you might be able
to arrange for the farmer to bring it to you if you give him or her something
for their gas and time.
Another rural source for
excellent mulch is to clean out the stalls of goats, sheep, cows or
horses. (
Note: un-composted horse manure can be full of herbicides which are toxic to many flowers and vegetables - especially tomatoes and peppers. See our articles about this issue
here and
here.) It's ideal if their bedding material is straw. If wood chips or
saw dust is their bedding, you'll only want to use it if its been
composting for a year or more. The heavy balance of carbon in the
wood-products can actually pull nitrogen from your soil. Also if you are using
horse manure, be sure it has thoroughly composted for at least a year so that all grass seeds are no longer viable.
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| A delivery of spoiled hay |
When to mulch? In the cycle of a
year's gardening, there are two main times for a mulch "push". At the
end of harvest, when you're putting your garden to bed, if you have a
large enough quantity of grass clippings, raked leaves or animal bedding
from cows, goats, sheep or horses that has manure mixed in, you can
apply this liberally and roto-till it into the ground. This gives you
the whole winter for the micro-livestock to digest it in time for spring
planting. It is not a good idea to apply, and till your mulch into the ground in
the spring time because the "browns", the more woody/cellulose aspects
of the mulch that are high in carbon will bind with the nitrogen in your
soil and effectively rob it from your spring seedlings if tilled in too
close to their planting.
The second cycle of mulching
begins in the spring and continues throughout the summer as you plant
your garden rows. This includes deep applications (6" or more") of hay or straw flakes in the garden
paths.
This provides comfortable and attractive paths to walk on and tend your
beds. It also slowly feeds the micro-organisms in your soil and keeps
moisture-levels and soil-temperatures at a more constant level.
You
can also till in fresh grass clippings and combinations of grass
clippings and leaves directly into garden beds as long as you wait 10-14
days for planting. See
this post on the methods we use.
If you're using all that hay and grass clippings, what about weeds?
This is a question we get asked a lot. Bringing a whole bunch of hay
into your garden may not seem like a good idea as you also bring a bunch
of weed seeds that can then germinate in your garden soil. The key is
in applying
enough mulch, soon enough.
How much is enough? You
want to put enough of the material to keep in the moisture and block the
sun from reaching any weeds growing in the paths. Hay bales often
naturally break into "flakes". Just lay these in your paths, end to end,
without fluffing them (which can scatter seed into your beds) and make
it easier for weeds to grow through (5" to 8" is ideal). If you're using
dried leaves, they too should be about 6" thick. Grass clippings work
best if you put them locally around the base of plants (leave about a 2"
gap around the stem of the plant as the grass can literally burn your
plants if it is applied thick while still green). When applied liberally
in the paths
they can form a gooey surface that can be quite slick and dangerous to
walk on. They also become "felted" or matted down making it harder for
water to seep through to the plant's roots. You'll be amazed to see,
over the course of a year, that the 8" of mulch you applied in May, June
or July, will be almost totally digested (from below) by the following
March/April when you begin the spring plantings. Worms travel up to the
surface of the soil at night and feed on the mulch, carrying it back
down into the soil in their gullets and distributing it as castings
throughout your garden.
You will rarely find exposed,
bare soil in Nature unless there has been a recent disturbance such as a
fire or landslide. In our gardens we try to imitate nature, leaving as
little bare soil as possible. Bare ground makes it very easy for
weed-seeds to take hold.
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| Alpine Garden - 10 weeks after breaking ground 2009 |
Sources for mulch:
- Municipal leaf-gathering
- Raking your own (offer to rake your neighbors' in exchange for keeping the leaves.)
- Farmer's moldy or spoiled hay
- Set up your own collection site: Rural transfer stations appreciate
any solution that keeps material out of the landfill. Below is a picture
of a collection site Chris established near his farm in northern
California.
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| A gathering site for mulch donations at the local, rural transfer station. |
Here are some other pictures of our gardens showing the deep mulch technique:
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| Another example of how the garden looks--fully mulched--with hay. |
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| Tilling in leaves in the fall - so they have time to decompose by spring. |
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| The potatoes were mulched first with leaves and we're adding oat-straw in the picture. |
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| This was a
"lawns-to-gardens" project where we simply scalped the grass from the
beds and mulched the lawn path-ways. The plastic on left was placed to
"solarize" the grass (kill it in preparation for fall-crop planting). |
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| Here Chris is using lettuce that has "bolted" (gone to seed) as mulch in the potato patch. Oat straw was then placed over it. |
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| Fun in a leaf ring! (Robin, Chris' son in a "nest" of leaves 1996) |
Other related posts:
Herbicide Contamination in Manure, Compost and Grass Clippings?
Grass Clippings and Leaves for Mulch
Mulch We Love, and Why
Preparing Garden Beds - One Low-Tech Way
Hay-Bale Compost
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