Not All Mulch Is Created Equal

How your mulch is made matters

Most budget mulch film has a smooth surface on both sides. 

It's a typical blown plastic film, straightforward to produce, low cost to buy. And, in mild conditions, it does the job well enough.

The problems start when temperatures climb. Smooth plastic heats up, expands, and stretches. And when it cools down at night, it doesn't bounce back. Now your loose filmlifts off the bed and starts flapping. Wind gets under it. It tears, and the exposed soil dries out. You end up spending time and money re-laying film instead of managing your crop.

On the other hand, embossed mulch (also known as cast mulch) is manufactured with a textured surface imprint using specialised machinery. That texture acts like a spring: when the plastic heats and expands during the day, the embossed pattern allows it to contract back to its original shape as it cools. 

Day after day, it keeps returning to a tight fit. 

What’s more is that embossed film conforms to the soil bed during application. It goes on like a glove, which means faster machine lay and a more consistent fit from the start. 

The textured surface also disrupts wind. Where smooth film catches air like a sail, embossed texture breaks up airflow across the surface. Less lift, less tearing, fewer mid-season failures.

In the hot and dry climate of Southern Africa, where daytime temperatures regularly push plastic to its limits, that springy recovery behaviour is what separates a bed that holds all season from one that doesn't.

How mulch colour works for your crop

Most growers default to black mulch. It makes sense because black absorbs radiation and blocks the light that weeds need to germinate. Black, however, absorbs everything, heat included. In summer, or in hot-climate regions, this can push soil temperatures too high, causing seedlings to stress, shallow roots to overheat, and the mulch itself to become the problem.

A silver or white upper surface changes the equation. It reflects radiation, preventing overheating, while the dark underside still suppresses weeds. The reflected light then bounces up into the crop canopy, boosting photosynthesis, so you're managing temperature and helping your plants access more light.

Brown films work differently. Brown transmits near-infrared radiation (the wavelengths that warm soil) while blocking visible light, which is what weeds need to grow. This means you get soil warming and weed suppression from the same film. Particularly useful for crops planted in cooler months when you want warmer roots but can't afford weed competition.

Bi-colour films stack these benefits. One colour does the work on top, another does different work underneath. 

Brown/silver, black/white, black/silver. They all have their uses. The right combination depends on your crop, your planting season, and your local climate. 

And this is where ordering the cheapest black plastic and hoping for the best falls apart.

The mulch your strawberries want

Strawberry farming is one of the clearest examples of why mulch selection matters. Strawberries sit close to the ground and have shallow root zones, making them vulnerable to soil contact, fruit rot, temperature swings and moisture-related diseases. 

To help prevent all this and protect this fragile crop, choosing the right mulch is key.

Brown/silver bi-colour on an embossed base will likely give the highest chances of a successful yield. 

Silver on top reflects heat away from the fruit and repels certain pests. Brown underneath moderates soil temperature and suppresses weeds without overheating the root zone. And the embossed texture keeps the film tight against raised beds all season. So there is no lifting, no gaps, no exposed fruit touching wet soil where disease can easily take hold.

This bi-colour mulch is a specific answer to a specific crop's needs.

Think total cost, not roll cost

When it comes to your crops, every decision you make matters. The answer is not "always buy the most expensive mulch", but rather, “know what mulch will give your specific crop the highest chance of success.” 

Mulch selection deserves the same thought you'd give to the more “expensive” choices on your farm, like your irrigation setup or your fertiliser programme. 

Think about the total cost over time, not just the cost per roll, and ask your supplier about colour options and whether their film is embossed or smooth. This could be what protects you from re-application, exposed beds, and crop stress when your film gives up mid-season.

If you're not sure which mulch specification suits your operation, that's exactly the kind of conversation we're here for. 

Reach out on +27 21 987 6980 or info@vegtech.co.za.

We'll help you match the right product to your crop, your climate, and your conditions.