As a rule, almost every raised bed has to be lined with foil to increase its lifespan. This is especially true for raised beds made of wood, because the material, which rots quickly, must not come into permanent contact with moisture. But raised stone beds often also need to be covered with foil, as freezing moisture, for example, attacks the masonry in winter. But which film should you choose for the raised bed?
Which film is suitable for a raised bed?
Pond liner, rubber foil (EPDM foil) and bubble wrap are best suited for a raised bed as they are robust, impermeable to water and free of harmful substances. PVC films should be avoided as they may contain carcinogenic plasticizers.
Pond Liner
Pond liner is produced specifically for the construction of garden ponds and is therefore not only very robust and impermeable to water, but often also UV-resistant (€73.00 at Amazon). This property ensures that the film lasts a long time because UV light makes the material porous. Pond liners also have the advantage that they must be as non-toxic as possible for fish and plants to be stocked with - many fish species in particular are extremely sensitive to toxins. And anything that doesn't harm fish should also be suitable for raised bed plants.
Stay away from PVC
This is why you use it to line raised beds - especially when it comes to raised vegetable beds! – If possible, no PVC films. These contain harmful plasticizers that pass through the soil into vegetables and are suspected of causing cancer in humans. Therefore, when purchasing, pay attention to films that are free of these additives.
Rubber film (EPDM film)
Durable EPDM films are usually made from natural rubber and are characterized not only by their extreme resilience and longevity, but also by the fact that they do not emit any harmful substances. For this reason, they are harmless to plants and other living beings (which nest in every raised bed) and are therefore environmentally neutral. However, they are also very expensive.
Pubble foil
This film is also called a drainage film for good reason and is intended to help prevent waterlogging. One side of this film is equipped with numerous knobs that drain excess water straight down from the raised bed. When buying, however, be sure to pay attention to the material: the cheap brands in particular are often made of unstable plastic and contain plasticizers and other harmful substances.
Tip
Instead of using foil, you can also protect your raised bed from moisture with other materials. For example, an old bathtub or zinc tub can be converted into a raised bed and made attractive with a wooden or stone border, for example.
