Mulching enriches and protects soil, helping provide a better growing environment.
In your garden
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 similar materials--or inorganic--
such as stones, brick chips, and plastic. Both organic and inorganic
mulches have numerous benefits.
• 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 temperature
• 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 provide organic matter which helps
keep the soil loose. This improves root growth, increases the infiltration
of water, and also improves the water-holding capacity of the soil.
Organic matter is a source of plant nutrients and provides an ideal
environment for earthworms and other beneficial soil organisms.
While inorganic mulches have their place in certain landscapes, they
lack the soil improving properties of organic mulches. Inorganic mulches,
because of their permanence, may be difficult to remove if you decide
to change your garden plans at a later date. Therefore, this tip sheet is
limited to the use of organic mulches.
You can find mulch materials in your own yard! Lawn clippings make
excellent mulch. While not particularly attractive for a flower bed, they
work wonderfully in the vegetable garden.The fine texture allows them
to be spread easily even around small plants. However, grass clippings
are becoming scarce because of the increased popularity of mulching lawnmowers that provide many of the same benefits of mulching to lawns. Newspaper, as a mulch,works especially well to control weeds. Leaves
are another readily available material to use as mulch. Leaf mold, or the decomposed remains of leaves, gives the forest floor its absorbent spongy structure. Compost makes a wonderful mulch if you have a large supply. Compost not only improves the soil structure but provides an excellent
source of plant nutrients. Bark chips and composted bark mulch are available
at garden centers. These make a neat finish to the garden bed and will eventually improve the condition of the soil. These may last for one to three years or more depending on the size of the chips or how well composed the
bark mulch is. Smaller chips tend to be easier to spread, especially
around small plants. Depending on where you live, numerous other
materials make excellent mulches. Hay and straw work well in the vegetable
garden, although they may harbor weed seeds. Seaweed mulch, ground
corn cobs, and pine needles can also be used. Pine needles tend to increase
the acidity of the soil so they work best around acid-loving plants such as
When to apply mulch
Time of application depends on what you hope to achieve by mulching.
Mulches, by providing an insulating barrier between the soil and the air, moderate the soil temperature. This means that a mulched soil in the
summer will be cooler than an adjacent unmulched soil; while in the winter,
the mulched soil may not freeze as deeply. However, since mulch acts as
an insulating layer, mulched soils tend to warm up more slowly in the spring
and cool down more slowly in the fall than unmulched soils. If you are using mulches in your vegetable garden , it is best to apply them after the soil has
warmed up in the spring. Cool,wet soils tend to slow seed germination
and increase the decay of seeds and seedlings. If adding additional layers
of mulch to existing perennial beds,wait until the soil has warmed completely.
Mulches used to help moderate winter temperatures can be applied late
in the fall after the ground has frozen but before the coldest temperatures
arrive. Applying mulches before the ground has frozen may attract rodents looking for a warm over-wintering site. Delayed applications of mulch should prevent this problem as, hopefully, the creatures would already have found
some other place to nest! Mulches used to protect plants over winter should
be loose material such as straw, hay, or pine boughs that will help insulate
the plants without compacting under the weight of snow and ice. One of the benefits from winter applications of mulch is the reduction in the freezing
and thawing of the soil in the late winter and early spring. These repeated
cycles of freezing at night and then thawing in the warmth of the sun
cause many small or shallow rooted plants to be heaved out of the soil.
This leaves their root systems exposed and results in injury or death.
Mulching helps prevent rapid fluctuations in soil temperature and reduces
the chances of heaving.
1. Begin by asking yourself the following questions.
What do I hope to achieve by mulching?
How large is the area to be mulched?
How much mulch will I need to cover the area?
Mulch is measured in cubic feet. As an example, if you have an area
10 feet by 10 feet and you wish to apply 3 inches of mulch, you would
need 25 cubic feet. (10' x 10' x .25' = 25 cu. ft.)
2. Determine what mulch material to use and purchase or accumulate
what you need.
Mulch can often be purchased bagged or bulk from garden centers.
Bulk may be cheaper if you need large volumes and have a way to haul it. Bagged mulch is often easier to handle, especially for smaller projects.
Most bagged mulch comes in 3-cubic feet bags.
Collect leaves in the fall.
Chop with a lawnmower or shredder. Whole leaves tend to compact if
wet or blow away if dry. Chopping will reduce the volume and facilitate composting.
Compost leaves over winter. Some studies have indicated that freshly
chopped leaves may inhibit the growth of certain crops. Therefore, it may
be advisable to compost the leaves over winter before spreading them.
Spread them immediately to avoid heating and rotting.
Save your own newspapers.
Smaller chips are easier to spread, especially around small plants.
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. Similar
to bark mulch. If using fresh wood chips that are mixed with a lot of
leaves, composting may be beneficial. Best to chop and compost before spreading. If using dry leaves, apply about six inches deep. 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. 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. Use only newspaper text
pages (black ink); color dyes may be harmful to soil microflora and fauna
if composted and used.
Use 3 or 4 sheets together, anchored with grass clippings or other mulch material to prevent blowing away.
The amount of mulch to apply will be determined by the mulch material
you are using.
Do not apply mulch directly in contact with plants. Leave an inch or so of
space next to plants to help prevent diseases flourishing from excessive humidity.
Remove weeds before spreading mulch. Bark mulch and wood chips
are sometimes used with landscape fabric or plastic. The fabric or plastic
is laid on top of the soil and then covered with a layer of bark chips. A
caution to this practice: while the plastic or fabric may initially provide
additional protection against weeds, as the mulch breaks down,weeds
will start to grow in the mulch itself. The barrier between the soil and the
mulch also prevents any improvement in the soil condition and makes
planting additional plants more difficult.