Mulching

Plant Material Maintenance

Why use mulch?

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.

Reduce Soil Erosion

Reducing drop impact. Slowing water flow.

Increase Soil Fertility

Decomposition of organic matter. Subsequent release of nutrients.

Moderate Soil Temperatures

Soil surface cooler in the summer and warmer in the winter.

Mulched soil much less likely to freeze.

Organic Mulches

Wood chips Shredded bark Bark nuggets Cocoa bean hulls Compost Many others…

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 hullsAnnualsTheobromine has an oral LD50, for dogs, of

300 mg/kg Keep mulch away from the trunk.

No Mulch Volcanoes!

Inorganic Mulches

River rock, lava rock, pea gravel, crushed bricks, etc…

Advantages Does not get washed/blown away. Does not break down.

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.

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.

Mulch Edges: Keep mulch in the bed and turf out of the bed.

Machine edge Edging

Plastic Metal Stone Brick Poured

Bullet Edgers

Steel Landscape Edging

Poured Concrete Edging

Mulch Math

Mental Math 1 cubic yard of mulch covers an area measuring

10’ x 10’ x 3” deep

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”2,500 sq. ft.

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?

About 2.3 cu. yds. 25 ft

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.

20 ft

30 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.

24 ft

The End