Mulching: Why, When, How?

In most cases we recommend using hardwood bark mulch for your landscape beds.  Hardwood bark mulch has a high aesthetic value, and it adds organic matter to the soil as it breaks down.

Why Mulch?

The benefits are numerous:

·    Improves aesthetics

·        Reduces the weed population

·        Buffers soil temperature

·        Conserves soil moisture

·        Adds organic matter to the soil

·        Limits erosion

When?

Mulching every year is not necessary, but that will produce the best aesthetic result.  If annual mulching is done, the buildup of mulch should be monitored.  An excessively thick layer of mulch will do more harm than good.  Mixing mulch that remains from the previous year into the soil will help it break down more quickly.

Mulch can be put down in any season.  For aesthetic value, the best time to mulch is the spring. Mulch should be put down after the soil begins to warm up.  If mulch is applied too early it will keep the temperature of the soil too low for plant growth.

Protective mulch that is intended to insulate plant roots should be put down after the ground freezes.  This will prevent freezing and thawing cycles that harm plant roots.  

How?

After deciding to mulch, selecting what mulch to use is the next step.  The function of the mulch plays an important role in its selection. 

Types of Mulch

Organic Mulches

Bark - Bark mulches are available in chipped and shredded forms.  Composted mixes of bark and wood chips make excellent mulches

Compost - Compost is excellent for the soil, though it may lack aesthetic value.

Licorice Root - Very hard to locate, and not worth the exorbitant price.

Pine Needles - Great for plants that like acidic conditions.  Becomes extremely flammable.

Wood Chips - Only composted wood chips should be used.  Watch out for dyed products, they normally are not composted.

Inorganic Mulches

Geotextile - A synthetic fabric that lays on the ground.  Excellent for eliminating weed problems.  May need to be covered with another type of mulch.

Plastic - Not a good choice.

Stone - Available in various shapes, sizes, and colors.

Application

Sources

This sheet has been compiled from experience and information from the Pennsylvania Certified Horticulturist Reference Guide