Why use mulch?
Mulch is used primarily to conserve moisture and to provide a weed
barrier. It is also used to provide a pleasing cosmetic background for
plant areas. In the Gulf Coast region, mulch is also used to insulate
and lower the soil temperature in the summer months.
When should mulch be applied?
There are three primary times to mulch on the Gulf Coast for
horticultural needs: In spring, to retard weed emergence, in
mid-summer to protect roots from high temperatures and from
water loss, and in early winter, to protect roots from
freezing. Mulching can be done at any other time of the year for
cosmetic reasons and to add organic material to the planting areas.
How much mulch should be applied?
In general, mulch should be applied in a layer about 1 1/2 to 2
1/2 inches thick for optimum moisture retention and soil
temperature benefits.
What kind of mulch is best?
Landscape Depot feels that hardwood bark or hardwood-cedar blend makes the best mulch
for primarily technical reasons. The types and benefits of different
types of mulch are discussed below:
| Hardwood bark:
This material is the best mechanical mulch, since it is fibrous and
will interlock, which keeps it from washing away in hard rain. It is
heavy enough to provide good moisture retention in the summer
months, yet it allows good water and air permeability. Hardwood bark
also provides anti-fungal and anti-insect properties to the soil. As
it decomposes, it breaks down into a very good organic soil
amendment. Bark is much better than other materials from a plant
nutrition standpoint because it does not "rob" nitrogen
from the plants like mulches made from wood or leaves. Cedar Mulch: This material is also a shredded mulch and will not erode. It has similar properties to the hardwood bark, and has some limited ability to repel insects. It is excellent mulch by itself, and an outstanding mulch as a hardwood-cedar blend. Pine Bark: Pine bark is an acceptable mulch, but it lacks the interlocking ability of hardwood bark, and it therefore tends to wash away easily in strong Gulf Coast rain. It has the good properties of all barks concerning insects and fungus, and will not rob significant nitrogen. Due to its chip or flake structure, pine bark makes an excellent soil amendment or basic material for potting soils. Composted brush and grass (native mulch):Ground-up brush that has been composted is sometimes used for mulch, but Landscape Depot does not recommend its use alone. Most of this "native" mulch or wood mulch (or sometimes "hardwood" mulch) contains uncomposted white wood, which has very poor properties: It promotes fungal growth that is harmful to plants, and it can attract the wrong kind of insects (termites). We recommend that it only be used when it can be blended with bark, so that the fungus and insects can be naturally controlled. Some local producers also use the term "hardwood mulch" in an attempt to sound like "hardwood bark mulch" so exercise caution when ordering. Colored wood chips or crushed rock: These materials should not be used above plant roots, since moisture retention is poor and no decomposition products (organics) are ever added to the soil. |