Mulching
Plant Material Maintenance
Why use mulch?
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Conserve soil moisture.
Reduce soil erosion and water runoff.
Increase soil fertility (organic).
Protect surface soil from compaction.
Moderate soil temperatures.
Suppress weed growth.
Improve the appearance of the landscape.
Conserve Soil Moisture
Blocking solar radiation.
 Blocking wind.
 Reducing evaporation of water from the
soil.
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Reduce Soil Erosion
Reducing drop impact.
 Slowing water flow.
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Increase Soil Fertility
Decomposition of organic matter.
 Subsequent release of nutrients.
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Moderate Soil Temperatures
Soil surface cooler in the summer and
warmer in the winter.
 Mulched soil much less likely to freeze.
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Organic Mulches
Wood chips
 Shredded bark
 Bark nuggets
 Cocoa bean hulls
 Compost
 Many others…
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Shredded Hardwood Bark Mulch
Shredded Pine Bark Mulch
Compost
Cocoa Bean Mulch
Medium Bark Nuggets
Small Bark Nuggets
Organic Mulches
If possible use composted mulch materials
with a C:N ratio ≤ 25:1
 Cocoa bean hulls
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 Annuals
 Theobromine
has an oral LD50, for dogs, of
300 mg/kg
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Keep mulch away from the trunk.
No Mulch Volcanoes!
Inorganic Mulches
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River rock, lava rock, pea gravel, crushed bricks,
etc…
Advantages
 Does
not get washed/blown away.
 Does not break down.
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Disadvantages
 Does
not benefit soil.
 Difficult to change at a later date (use barrier).
 Can be problematic next to sidewalks for snow
removal.
Rock Mulches
Landscape Fabric
Permeable fabric laid between soil and
mulch.
 Always use under rock mulch.
 Can be problematic after installation.
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 Weeds
grow on top and roots grow through
causing difficulty in removing weeds.
 Prevents the decomposition of organic
mulches.
How Much Mulch?
Different articles cite different amounts.
 Generally speaking 2-3 inches is sufficient.
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Mulch Edges: Keep mulch in the
bed and turf out of the bed.
Machine edge
 Edging
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 Plastic
 Metal
 Stone
 Brick
 Poured
Bullet Edgers
Steel Landscape Edging
Poured Concrete Edging
Mulch Math
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Mental Math
1
cubic yard of mulch covers an area measuring
10’ x 10’ x 3” deep
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You desire to mulch a 2,500 square foot
bed with 2 inches of shredded bark.
How many cubic yards of shredded bark
mulch will you need to buy and bring to
the job site to accomplish this:
2,500 sq. ft.
2”
Convert 2 inches to feet:
2 inches x 1 foot = 2 = 1 = .166 feet
12 inches 12 6
Determine volume in cubic feet:
2,500 square feet x .166 feet = 415 cubic feet
Convert cubic feet to cubic yards:
415 cubic feet x 1 cubic yard = 15.37 cubic yards
27 cubic feet
If the bed is square or rectangular in
shape, the total bed area is simply the
length x width.
 How many cubic yards would you need
to cover the area below with 2 inches of
mulch?
25 ft
 About 2.3 cu. yds.
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15 ft
If the bed is triangular shaped, the total
bed area is equal to 1/2 (base x height).
 How many cubic yards would you need to
cover the area below with 2 inches of
mulch?
 About 1.85 cu. yds.
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30 ft
20 ft
If the bed is circular, the total bed area is
π x radius2. Remember the radius of a
circle is ½ the diameter!!!
 How many cubic yards would you need to
cover the area below with 3 inches of
mulch?
 About 4.2 cu. yds.
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24 ft
The End