Eddie Seagle, Ed.D.
The Moultrie Observer
Landscaping should look great throughout the year, not just when it has been recently mulched.
Mineral and synthetic (inorganic) mulches make good mulching choices, but do not contribute any beneficial organic matter to the soil.
Advantages of the mineral mulches (stone, pea gravel, etc.) over the organic materials (bark, pine straw, etc.) include their ability to withstand wind conditions and remain intact, their significance in not harboring weed seeds or diseases, and their neutral impact on soil chemistry (do not rob the soil of nitrogen).
Mineral mulches (fine textured and coarse textured) are used in shrub beds, driveways, walkways, foundation beds, and in steps. Crushed stone and gravel are appropriate mulches for rock gardens and select beds. Some mineral mulches can be custom colored to blend in with features of the home or landscape.
The disadvantages of mineral mulch particles include being thrown by rotary lawn mowers during mowing (potentially causing injury or damage) to people and property, and their tendency to migrate downward into the soil profile over time. The latter can be corrected by using a synthetic fabric placed between the mulch and the soil surface.
Geotextiles (or landscape fabrics) have been significant in mulches over the last several years.
These woven and nonwoven fabrics of polypropylene or polyester are an improvement over the traditional black plastics. They will block weed growth, reduce surface evaporation, and allow water, fertilizer, and oxygen to penetrate easily into the soil.
However, if they are used alone as mulches, geotextiles can be degraded and weakened by the effects of ultraviolet radiation from the sun. These geotextiles are used more frequently as liners between the mulch and the soil thus enhancing the weed-suppressing ability of the mulch while separating the mulch and soil.
Nonwoven polyester fabrics generally last longer and have greater resistance to chemical and temperature degradation than do polypropylene materials. However, the polyester mulches are more expensive than the polypropylene materials. The polypropylene fabrics are developed by weaving fibers together or bonding short or continuously spun fibers together. The nonwoven fabrics are bonded by needle punching, melting with chemicals or heat, gluing, or molding.
Since several geotextiles are in the market, it is critical to choose the proper fabric. Factors to consider in the selection process include the ease of applying the material to the landscape, the ease with which water penetrates through it, the effectiveness of the material in suppressing weed growth, and the relative cost.
Before any geotextile is placed on the ground, the subject area must be cleaned of all weeds and the surface shaped for effective surface drainage. Most manufacturers suggest that the installer lay the fabric into position and carefully cut small slits where plants are to be installed.
However, most landscapers who have worked with these geotextiles have found that the application is more accommodating when the shrubs are planted in weed-free soil. The fabric is laid onto the ground and cuts are made that to allow the fabric to be worked around the base of each plant. The final step is to apply a 1- to 3-inch layer of mulch on top of the geotextile to improve appearance (curb appeal), reduce wear, and decrease deterioration caused by the sun's rays.
Although such geotextiles are an advancement in mulching technology, they don't prevent all weed growth. Weeds that germinate and grow in a bark or wood chip mulch can grow right through the fabric. This is especially a problem with troublesome weeds such as nutsedge, common bermudagrass, Florida betony, etc. Continuously pull and remove any weeds attempting to grow in the completed bed which will establish and grow through the geotextile for survival.
Rubber mulches are environmentally-friendly and money-saving alternatives to the traditional bark and wood mulches for landscaping projects. Rubber mulches are more durable, cost-effective, and lower maintenance than wood mulches, stone and other traditional landscaping materials. Also, they do not harbor harmful pests like termites, rodents or spiders, and they are resistant to mold and fungus. Available in fade-resistant colors, landscape rubber mulches are a superior landscape solution for your residential or commercial projects.
Rubber mulches are available in several colors including black, gray, redwood, brown, green and blue. They keep their fade-resistant color for several years; will not crack, splinter, blow or wash away; will not compress or decompose; will not harbor insects or diseases; and will not absorb water or freeze. They save trees and provide an opportunity to recycle thus reducing the scrap tire count at landfills. They are non-allergenic and harmless to plants, pets and children without depleting our natural resources and are excellent choices for landscape beds and playgrounds.
Natural pine straw is in high demand and varies in age, color, quality, price, etc. and decomposes readily (about two months of quality curb appeal from initial placement). Therefore, synthetic pine straw is an excellent alternative which is made from recycled polypropylene which does not absorb water or chemicals. It is recycled easily from bottle scrap, carpet backing, fiber and yarn.
Synthetic pine straw is an excellent choice for commercial and industrial properties wanting quality curb appeal and understanding the in’s and out’s of landscape maintenance. Also, it is an excellent choice for homeowners who want an attractive appearance in the landscape and favorable environment for their plants and flowers.
The downside of using mulches in landscape beds under existing trees and large shrubs is the contamination from falling leaves and needles onto the existing mulch surface. If you have selected a mulch different from these falling leaves or needles then clean-up can be problematic, but do-able.
Do not allow the depth of any of these mulches to exceed 3 to 4 inches and prevent any build-up around the base of the tree trunks for health reasons. Maintain a consistent depth across an open bed area since low or bare spots are more prone to weed problems and soil contamination into the mulch. Uneven mulch does not properly insulate the soil and reduces curb appeal.
May your mulching efforts be worthwhile throughout the year and support environmental stewardship, sustainability and curb appeal. Happy Thanksgiving to all!