Press Release
For Spring/Fall Time Frame
UNIVERSITY PARK, Pa. -- Applying mulch may be one of the simplest elements of working in a garden, but a Penn State horticulture specialist says there's a lot more to it than just dumping a bag of mulch around plantings.
"More and more gardeners are using mulch materials as an ornamental part of their landscape design, choosing mulches for texture and color," says Robert Nuss, professor of ornamental horticulture in the College of Agricultural Sciences. "If you're mulching in a large area with no plants, then there really are no guidelines needed for application. If you are mulching around plants, it's best to follow a few simple rules that will increase growth and improve the health of a plant."
Nuss says most mulches are comprised of hardwood bark, cypress bark, bark nuggets, wood chips or other materials.
Nuss suggests choosing a mulch that features:
--Consistent color and texture.
--Compaction resistance.
--Wind and water erosion resistance.
--Slow rate of decomposition.
--Ability to reduce weed growth.
"All mulches must allow an exchange of gases -- oxygen into the soil and carbon dioxide out of the soil -- as well as water penetration into the soil," Nuss says. "A coarse-textured mulch will enhance both gas exchange and water penetration. If your choice of mulch slows or stops these processes, plants will decline and die."
Most mulches should be just two to four inches deep, Nuss explains. Gardeners should use the low end of that scale on heavy clay soils, and the upper end of the scale for loose, sandy soils. "Too much mulch smothers the roots by reducing gas exchange," he says. "Deep layers of mulch also will absorb all the water from light rains, holding it well above the root system."
Nuss also points out other benefits from mulch:
--Moisture conservation. If mulch is applied correctly, soil water evaporates slowly, giving plants a consistent moisture source. "As the mulch breaks down, the soil's ability to hold water may improve," Nuss adds. "Mulched plants always will survive a drought better than unmulched plants."
--Water Infiltration. Mulch cushions the impact of raindrops against the soil surface, allowing water to gently flow into the soil. "When rain falls on bare soil, it disrupts the soil structure at the surface and causes a certain amount of compaction," Nuss says. "By slowing down the inward movement of water, mulch reduces soil erosion."
Nuss warns that gardeners should not pile mulch on plants indiscriminately, particularly around the trunks of trees or shrubs. "Piling mulch against a trunk causes bark decay and other health problems," Nuss says.
He also points out that gardeners who create large mulched areas with no plants
within a garden may want to lay a covering of landscape fabric or plastic on
the soil to control weed growth.
________________________________________________________________________
To contact Robert Nuss, please call (814) 863-2196.
Editor: John Wall
Phone: 814- 863-2719 office
Email: jtw3@psu.edu
PR #04350
| Back to Related InfoGraphic "Mulching Plants and Shrubs for Growth and Health" |
| Welcome | Back to Archive List | AgIS home |