 |
| 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.
 |
| Mulching feeds your "micro-livestock" |
|
In these first years of establishing new
garden sites in Alpine and Monroe, we also use 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.
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. 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. 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" therapy -ha.) You can use tarps to haul the leaves to
your garden, or bag them in leaf-bags. Sometimes 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. The thinner the leaf,
the easier it breaks down. Maple is our favorite. Oak takes a long time
to break down and we wouldn't recommend using it unless you mix it with
other types of leaves. Fruit-tree leaves are also great.
Don't ever use walnut leaves as they have natural substances in them that are poisonous to plants and will destroy your garden's fertility.
 |
| Maple leaves make excellent mulch |
If you live in, or near the country,
spoiled hay
makes a great mulch. 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 something
for his gas and time.
Another rural source for
excellent mulch is to clean out the stalls of goats, sheep, cows or
horses. 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 leech nitrogen from your soil..
 |
| 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 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. In our gardens, we have used a roto-tiller to loosen
the beds and then mounded them into raised beds by hand or with a
tractor. In future years, as the soil improves through the addition of
organic matter (hay, leaves etc), and the worm colonies have become well
established, we may be able to maintain these beds just using a
broadfork (a human-powered tilling tool that is less disturbing to the
soil).
Why mound the soil? We take the time each
year, to mound the soil into raised beds for several reasons. As you
can see from the photo, in the wetness of the Pacific NW spring, it
keeps the roots from drowning by raising them above the water table.
Also, if your rows run east to west, the whole south side of them faces
the sun which can significantly warm the soil temps; another great
advantage to most seedlings' early growth. The mounded soil doesn't ever
get walked on so, over several years, if you maintain your rows in the
same spaces, this soil becomes very light and fluffy, with good "tilth".
 |
| Advantages of raised beds... |
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. They key is
in applying enough mulch, soon enough. In our Alpine plot (80' x 100'),
in the first year, our friend was able to till the ground a good 8" deep
thus killing all the grasses/weeds already growing at the site. We
mulched heavy and early and, in the whole season we probably weeded
about a five-gallon bucket's worth of weeds out of the whole garden. No
kidding. For contrast, in the Monroe site, because of a very wet, cold
spring and the urgency of moving ahead and simply getting some things
planted before the soil had had time to drain sufficiently for deep
tilling, the ground was only tilled about 4" deep. Many of the weeds and
grasses were only "scalped" and came back strong in the garden beds, so
we have pulled
many wheelbarrows full of weeds out of that
garden. But the weeds are only coming up in the garden beds themselves.
In the pathways that are heavily mulched, the weeds exhaust themselves
before they can grow up to the light. As they die, they become mulch too
and their rootlets provide yummy snacks for the worms to follow along
as they work the soil.
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). 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.
 |
| Alpine Garden - 10 weeks after breaking ground 2009 |
A summary of the benefits:
- 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!)
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.
 |
| 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:
 |
| Another example of how the garden looks--fully mulched--with hay. |
 |
| Tilling in leaves in the fall - so they have time to decompose by spring. |
 |
| The potatoes were mulched first with leaves and we're adding oat-straw in the picture. |
 |
| 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). |
 |
| Here Chris is using lettuce that has "bolted" (gone to seed) as mulch in the potato patch. Oat straw was then placed over it. |
 |
Fun in a leaf ring! (Robin, Chris' son in a "nest" of leaves1996)
|
Links to other related posts:
Grass Clippings and Leaves for Mulch
Mulch we love and why
Preparing Garden Beds - one Low-tech Way
Mulch-es Gracias
