By Mark Wu, Co-founder & Technical Director, Sichuan Zhifang Net Industry Co., Ltd.
Almost every weed mat is bought once and judged once. The interesting question is what happens the second time you lay it, three or four seasons later, when the plants are different and the row has been reworked.
A mat that survives its first installation but tears on removal has cost you the full price and delivered half the value. A mat that lifts clean and goes back down has effectively been bought at half price.
Three properties, none of them on the price ticket.
Tension memory. A mat that has held tension for three seasons comes up flat. One that stretched and sagged has to be pulled straight again, and the stretched parts do not recover, so it goes back down with hollows in the same places.
Edge integrity. Removal is where raw edges fail. You lift a corner to get started, and if that corner runs, the first metre comes up as loose tapes.
Adhesion of silt. This one is underrated. Some fabrics shed soil and rain clean; others hold a layer of silt that has to be brushed off before the mat can be rolled. On a large area, that is a day of labour nobody budgets for.
The method is simple and almost never followed.
Lift from a corner that is already loose, not from a pinned edge. Pull along the length, not across it, because the weave is stronger in that direction. Roll rather than fold, and roll with the dirty side in, so the soil does not get ground into the fabric as you handle it.
Ground pins come out last, and they should be collected, not left in the row. A pin left in the ground is a puncture waiting for a tyre or a boot.
Knock the dry soil off first, before any water. Dry silt brushes off; wet silt turns into a paste that works into the weave.
Then wash with a hose on a flat surface. A pressure washer is a bad idea on woven polypropylene, because it frays the tapes and strips the surface layer that carries the UV package. If you must use one, keep it well back and keep it moving.
The one thing to be strict about is weed seed. A mat that has carried a season of seed heads does not need cleaning, it needs a decision: either it goes back under a crop where the seed cannot germinate, or it goes out of the system. Washing does not remove seed reliably.
This is where more mats are ruined than in the field.
Rolled wet and stacked, fabric mildews, and mildew on polypropylene is not just a stain: the fabric weakens along the fold lines and the next installation starts with a defect. Dry it flat or hung, in the shade, and store it rolled and off the ground.
Store out of sunlight. A stored mat is still a mat being aged by ultraviolet if it sits in a sunny corner of the yard all winter.
Two things change between installations.
The mat will be slightly shorter than it was, because some length is lost at the ends where it was pinned. Plan the new layout around that rather than discovering it mid-row.
Old planting holes will not line up with new plants, which is fine, because a new hole in a fresh spot is stronger than a stretched old one. Cut the new holes cleanly and keep them small. A mat that has been perforated repeatedly in the same zone is a mat with a weak strip.
A mat has reached the end when the tapes begin to splinter at the folds, or when it no longer holds tension when pulled. At that point it is not a weed barrier, it is a net that lets weeds through and gives you nothing back.
The other end point is contamination: a mat that has carried rhizomatous weeds, or one that has been under a diseased crop and cannot be cleaned properly. In that case the sensible decision is to replace it, because the cost of a reinfested row is larger.
Two mats, same price. One gives one installation, the other gives three. The second is a third of the price per season, and it also saves you the labour of laying it each time, which on a large area is the bigger number.
That is the whole case for buying on specification rather than on the roll price, and it is the reason we quote UV dose rather than a number of years.
Sichuan Zhifang Net Industry Co., Ltd. has been making woven ground cover and shade netting since 2011, from a plant of nearly 10,000 m² with more than 50 production lines, supplying growers in 32 countries. Our ground cover is woven from 100% virgin HDPE with a guaranteed UV stabilisation of 500 kly, in weights from 90 to 150 gsm, and every roll carries a ZF security label inside the pack.
Woven mat can, several times, if it is lifted along the length, dried properly and stored out of the sun. Thin non-woven fabric usually cannot, because it tears on removal.
Dry-brush first, then hose on a flat surface. Avoid pressure washers, which fray the tapes and strip the UV-bearing surface.
Yes, as long as it still holds tension and has no splits. Once it sags, silt collects in the hollows and weeds establish in the silt rather than through the fabric. If you want to know what kills a mat early, this covers the installation mistakes. Weights and widths are listed in the ground cover range, and the heavy woven grades are the ones that come up flat after several seasons.
