ARTICLES

05.08.2014

A JACK-OF-ALL-TRADES: THE VERSATILITY OF GEOTEXTILES IN THE LANDSCAPE

The simplicity of landscape fabric belies its versatility. Like a jack-of-all-trades, this product can be used in many different settings, for many different reasons. Whether it’s for creating man-made landscapes on lenten soils, which have poor engineering and geological qualities, reinforcement under pavers, the restriction of root growth, weed abatement, soil mulching or even keeping wildlife at bay etc. This product can do it all! Better still, it comes in a convenient roll which is easy for transporting and keeping and can be easily cut to fit in comparison with “thick” materials, for instance.

Landscape fabric is a part of a group more formally known as “geotextiles”. These polymeric construction materials are able to perform not only the function as the weed barrier. This fabric is used for separation – between soil layers – to realize the functions of reinforcement, filtration, separation and drainage. The basis for all geotextiles are permeable polymers such as polyamide, polyester, propylene, polyethylene with high density. There exist many types of geotextiles. It can be biodegradable or non-biodegradable, woven or non-woven, in a wide variety of thicknesses, hydrophobic and water-permeable.

Due to its chemical and physical characteristics (high extension and disruption tenability, low index of displacement, chemical and biological stableness) geotextiles are widely used for both landscape and hardscape practices.

But it doesn’t stop there. Protection, usually from the weather, is another vital use for these innovative materials. When a frost warning comes, draping geotextile fabric over threatened plant material can help it retain heat. Conversely, some plants can’t take too much blazing sun, either. Geotextiles can provide a layer of “sunblock” against a scorching hot spell. Fabrics are available that can provide anywhere from 10 to 90 percent protection from ultraviolet rays.

CONTROL THOSE WEEDS

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But in the landscape profession, geotextiles’ most common and familiar application is as a barrier material to keep weeds out. Many landscape contractors depend heavily on these fabrics for this purpose.

“We use tons of geotextiles,” share their experience veterans of “green industry”. Weeds are a big problem, weed abatement is not only the waste of time, weeds can lead to considerable losses. Due to their abilities to adapt, to remain stable and unpretentious weeds are considered mortal enemies and competitors of cultivated plants in the struggle for moisture, soil nutrients, light and space. Besides, weeds are a great place for causal organisms and vermins’ propagation and expansion.

Weed control fabric is much more sophisticated than the plain black plastic we have been using earlier. Landscape fabric has created a real revolution. Black plastic kept weeds out, but everything else, too. Landscape fabric is wonderful-it lets air, water and nutrients get to the roots.

However, to get the maximum benefit from these products, you need to remember the old axiom: “When all else fails, follow directions.” You must make sure that they’re being installed correctly. The root systems are prone to widen thus breaking soil integrity. Landscape fabric is used on a regular basis in such cases. The dense fabric is placed inside soil no closer than four feet from a tree’s trunk to adjust root growth.

“Landscape fabric is a great innovation, but it’s way overused,” comments Dmytro Brovarsky, the founder of «Landscape Technologies». “Over and over, we have found it to be improperly installed around saplings. With the lapse of time, it’s nearly fifteen to twenty years later, the fabric is literally inside the tree, embedded in the trunk, and it can’t be put out.” Our experts suggest placing landscape fabric no closer than four feet from a tree’s trunk.

You can also get landscape fabric that’s impregnated with trifluralin, an herbicide that inhibits the growth of both weeds and roots to protect cultivated plants. The general effect is selective. trifluralin is effective at preventing cell division so that a plant cant propagate itself and support its vital activity.

“This product (called Biobarrier) was developed 35 years ago, specifically for stopping roots from modification. Very often we find that we need to protect retaining walls from roots. “If there’s a tree up against a wall we’re building, or even as far as 20 feet away, we’ll use a barrier so the roots don’t come through. We’ve seen cases where roots will actually blow a wall up.”

But this herbicidal solution isn’t right for everyone. “Chemical herbicides aren’t healthy for soil microorganisms, in my opinion,” says Dmytro Brovarsky. “This is not to say that all herbicides are bad. I praise the new organic forms, like the ones made from corn gluten.”

Geotextiles are widely used to protect tree core. The tree trunk is wrapped with white geofabric. If necessary fabric is impregnated with a special agent to fight depredators. The special structure of the fabric allows core to breathe simultaneously protecting it from harmful sunrays and depredators.

HARDSCAPING AND EROSION CONTROL

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Geotextiles are invaluable in doing paving and erosion control work. For those applications, the experts of «Landscape Technologies» rely on a heavy-duty, non-woven polypropylene geotextile that is referred to as “stabilization” cloth. The principle of its operation is easy – it acts like a solid layer between other technological layers. I think everyone noticed some paving stones “tumble down”. It’s not builders’ fault. The project itself is likely to lack geotextile in such cases. You must keep in mind that good performance parameters depend heavily on the properly installed basis. “Though landscape fabric is not so popular here as in Western Europe, its prosperous future is near”, predict some contractors. Geotextile prevents integrating sand and the compacted material into the subsoils, increases the construction stability and minimizes the sag probability. You have a successful result, the possibility of easy maintenance and replanning with insignificant financial, labour and time expenses.

“We often use the non-woven type as drainage filters behind retaining walls and for soil separation between aggregate stone and natural soil”. We find that the non-woven type works well for drainage, and the woven type is better under pavers, patios and retaining wall bases. On the assumption of the right choice and installation landscape fabric is considered to be the most efficient and constructive decision in the questions of drainage and filtration. Geotextile creates a natural soil filter. Water escaping in the drainage from soil washes out the smaller parts. After that the connective structure of the bigger ones leans to the material thus creating the natural filter which sequentially reduces the washing out and even stops this process. One more example of the successful application of the landscape fabric is the protection of membranous waterproofing which is widely used in the projects of artificial waterscapes.

THEY KEEP GETTING BETTER

Landscape fabric is a great tool, but it isn’t foolproof. Another criticism is that sometimes weeds grow right through it. Roots can also grow under and over barriers. You need to make sure the fabric is rather dense and installed deeply enough. Some contractors only use landscape fabric when there is vital need to do it.

Many experts have seen significant improvement in geotextile technology in recent times. Geotextile used to be more of a felt-type material, which they still make in homeownergrade. What we use now is much stronger and denser. However, there’s still room for improvement. Experts don’t think weed control fabric lets enough water and nutrients get through to the plants.

Of course, manufacturers of landscape fabric are anxious to allay fears like this and promote their benefits. Test after test has proven that breathable fabric boosts soils’ cation exchange capacity (soil metabolism) by as much as double,” the veterans of the green industry assure you with confidence that a layer of polypropylene fabric, which is hydrophobic, placed on top of the soil will reduce plants’ water consumption needs by more than 60 to 70 percent, it does this without any side effects to the soils’ vital microbe and earthworm decomposition process.

Geotextile development isn’t standing still, not with all the manufacturers out there competing for your business. Competition and demand means that landscape professionals can look forward to new products hitting the market regularly. The qualities of these materials approximate to those of permeable polymers such as polyamides, polyester, propylene, polyethylene have been perfected with their biodegradable abilities. Besides it all, the psychological approach of the customers has changed as well – people are eager to overpay for the most ecofriendly packing!

 

A JACK-OF-ALL-TRADES: THE VERSATILITY OF GEOTEXTILES IN THE LANDSCAPE