Mulching
Mulching enriches and
protects soil, helping provide a
better growing environment.
In your backyard
Mulching is one of the simplest and
most beneficial practices you can
use in the garden. Mulch is simply a
protective layer of a material that is
spread on top of the soil. Mulches
can either be organic--such as grass
clippings, straw, bark chips, and simi-
lar materials--or inorganic--such as
stones, brick chips, and plastic. Both
organic and inorganic mulches have
numerous benefits.
Mulch:
• protects the soil from erosion
• reduces compaction from the
impact of heavy rains
• conserves moisture, reducing the
need for frequent waterings
• maintains a more even soil tem-
perature
• prevents weed growth
• keeps fruits and vegetables clean
• keeps feet clean, allowing access
to garden even when damp
• provides a "finished" look to the
garden
Organic mulches also improve the
condition of the soil.As these
mulches slowly decompose, they
Mulching works in gardens, around
trees and shrubs, and in other areas.
Backyard
Conservation
is a cooperative project of:
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Wildlife Habitat Council
April 1998 One in a series of 10 tip sheets on backyard conservation
BACKYARD Mulching
provide organic matter which helps or more depending on the size of attract rodents looking for a warm
keep the soil loose.This improves the chips or how well composed the over-wintering site. Delayed applica-
root growth, increases the infiltration bark mulch is. Smaller chips tend to tions of mulch should prevent this
of water, and also improves the be easier to spread, especially problem as, hopefully, the creatures
water-holding capacity of the soil. around small plants. Depending on would already have found some
Organic matter is a source of plant where you live, numerous other other place to nest!
nutrients and provides an ideal envi- materials make excellent mulches.
ronment for earthworms and other Hay and straw work well in the veg- Mulches used to protect plants over
beneficial soil organisms. etable garden, although they may winter should be loose material such
harbor weed seeds. Seaweed mulch, as straw, hay, or pine boughs that will
While inorganic mulches have their ground corn cobs, and pine needles help insulate the plants without
place in certain landscapes, they lack can also be used. Pine needles tend compacting under the weight of
the soil improving properties of to increase the acidity of the soil so snow and ice. One of the benefits
organic mulches. Inorganic mulches, they work best around acid-loving from winter applications of mulch is
because of their permanence, may plants such as rhododendrons and the reduction in the freezing and
be difficult to remove if you decide blueberries. thawing of the soil in the late winter
to change your garden plans at a and early spring.These repeated
later date.Therefore, this tip sheet is When to apply cycles of freezing at night and then
limited to the use of organic mulch thawing in the warmth of the sun
mulches. cause many small or shallow rooted
Time of application depends on
plants to be heaved out of the soil.
what you hope to achieve by
Mulch materials This leaves their root systems
mulching. Mulches, by providing an
exposed and results in injury or
You can find mulch materials in your insulating barrier between the soil
death. Mulching helps prevent rapid
own yard! Lawn clippings make and the air, moderate the soil tem-
fluctuations in soil temperature and
excellent mulch.While not particu- perature.This means that a mulched
reduces the chances of heaving.
larly attractive for a flower bed, they soil in the summer will be cooler
work wonderfully in the vegetable than an adjacent unmulched soil;
Applying mulch
garden.The fine texture allows them while in the winter, the mulched soil
to be spread easily even around may not freeze as deeply. However, 1. Begin by asking yourself the fol-
small plants. However, grass clip- since mulch acts as an insulating lowing questions.
pings are becoming scarce because layer, mulched soils tend to warm up a.What do I hope to achieve by
of the increased popularity of more slowly in the spring and cool mulching?
mulching lawnmowers that provide down more slowly in the fall than Weed control?
many of the same benefits of unmulched soils. Moisture retention?
mulching to lawns. Newspaper, as a Soil improvement?
mulch, works especially well to con- If you are using mulches in your veg- Beautification?
trol weeds. Leaves are another readi- etable garden or flower garden, it is b. How large is the area to be
ly available material to use as mulch. best to apply them after the soil has mulched?
Leaf mold, or the decomposed warmed up in the spring. Cool, wet c. How much mulch will I need to
remains of leaves, gives the forest soils tend to slow seed germination cover the area?
floor its absorbent spongy structure. and increase the decay of seeds and Mulch is measured in cubic feet.
Compost makes a wonderful mulch seedlings. As an example, if youhave an area
if you have a large supply. Compost 10 feet by 10 feet and you wish
not only improves the soil structure If adding additional layers of mulch to apply 3 inches of mulch, you
but provides an excellent source of to existing perennial beds, wait until would need 25 cubic feet.
plant nutrients. the soil has warmed completely. (10' x 10' x .25' = 25 cu. ft.)
2. Determine what mulch material to
Bark chips and composted bark Mulches used to help moderate win- use and purchase or accumulate
mulch are available at garden cen- ter temperatures can be applied late what you need.
ters.These make a neat finish to the in the fall after the ground has a. Mulch can often be purchased
garden bed and will eventually frozen but before the coldest tem- bagged or bulk from garden cen-
improve the condition of the soil. peratures arrive. Applying mulches ters. Bulk may be cheaper if you
These may last for one to three years before the ground has frozen may need large volumes and have a
2
BACKYARD Mulching
way to haul it. Bagged mulch is c. Leaves-- it the growth of certain crops.
often easier to handle, especially 1. Collect leaves in the fall. Therefore, it may be advisable to
for smaller projects. Most bagged 2. Chop with a lawnmower or compost the leaves over winter
mulch comes in 3-cubic feet shredder.Whole leaves tend to before spreading them.
bags. compact if wet or blow away if d. Grass clippings–
b. Compost-- dry. Chopping will reduce the 1. Spread them immediately to
Refer to the tip sheet on com- volume and facilitate composting. avoid heating and rotting.
posting for information on how 3. Compost leaves over winter. e. Newspaper–
to make your own compost. Some studies have indicated that 1. Save your own newspapers.
freshly chopped leaves may inhib-
Mulch materials
Bark mulch Amount to Apply Notes
2-4 inches Smaller chips are easier to spread, especially around small plants. Excellent for use
around trees, shrubs, and perennial gardens.When spreading mulch around trees,
keep the mulch an inch or two away from the trunk.A couple inches of mulch is
adequate.There is no need to apply the mulch 6 or 8 inches high, as often is seen.
Wood chips
2-4 inches Similar to bark mulch. If using fresh wood chips that are mixed with a lot of
leaves, composting may be beneficial.
Leaves
3-4 inches Best to chop and compost before spreading. If using dry leaves, apply about six
inches deep.
Grass clips
2-3 inches Thicker layers tend to compact and rot, becoming quite slimy and smelly. Add
additional layers as clippings decompose. Do not use clippings from lawns treated
with herbicides.
Newspaper
1/4 inch Apply sheets of newspaper and cover lightly with grass clippings or other mulch
material to anchor. If other mulch materials are not available cover edges of paper
with soil. Applying on a windy day can be a problem.
Compost
3-4 inches Excellent material for enriching soil.
3
BACKYARD Mulching
2. Use only newspaper text pages On the farm
(black ink); color dyes may be
harmful to soil microflora and Farmers use mulches in many ways.
fauna if composted and used. Conservation tillage is a common
3. Use 3 or 4 sheets together, practice that creates a mulch on the
anchored with grass clippings or soil surface. Unlike the once com-
other mulch material to prevent mon practice of plowing all crop
blowing away. residue into the soil, conservation
tillage leaves the crop residue on top
3.The amount of mulch to apply will of the soil.These pieces of corn
be determined by the mulch material stalk, straw, or bean stems help pro-
you are using. tect the soil against wind and water
erosion. Corn crops harvested for
General Guidelines: grain return large amounts of residue
a. Do not apply mulch directly in to the soil surface and are more
contact with plants. Leave an effective in preventing soil erosion
inch or so of space next to plants than crops with less residue such as
to help prevent diseases flourish- soybeans.
ing from excessive humidity.
b. Remove weeds before spreading Mulching is a common practice
mulch. among strawberry growers in north-
ern climates. In this situation, mulch
Bark mulch and wood chips are is used to protect the crop during
sometimes used with landscape fab- the winter and to help prevent early
ric or plastic.The fabric or plastic is blooming of the plants. Plants that
laid on top of the soil and then cov- bloom too early are more likely to be
ered with a layer of bark chips.A damaged by spring frosts.The mulch
caution to this practice: while the also helps keep the berries cleaner,
plastic or fabric may initially provide protecting them from soil splashing
additional protection against weeds, on them in the rain.
as the mulch breaks down, weeds
will start to grow in the mulch itself. Inorganic mulches are also widely
The barrier between the soil and the used in commercial agriculture. Clear
mulch also prevents any improve- plastic mulch can be particularly
ment in the soil condition and makes beneficial in giving warm season
planting additional plants more diffi- crops a head start.The clear plastic
cult. acts as a mini-greenhouse, warming
the soil underneath it. Particularly
For sources of where early sweet corn brings a pre-
mulch mium price, this practice can give a
grower a couple of weeks head start.
Check under mulches or garden cen-
ters or nurseries in the Yellow Pages. Also, research is showing that leav-
Your local community may also have ing crop residues helps hold carbon
wood chips from the removal of in the soil and aids in reducing
street trees that are available free to greenhouse gases.
residents.
4 Printed by the National Association of Conservation Districts 1-800-825-5547