To prevent the wooden raised bed from rotting and becoming rotten after just two winters, you should protect it from moisture. The most important thing is to separate the wood and the bed filling from each other - otherwise the moisture from the filling will penetrate into the wood and cause the rotting process. For this reason, lining the bed with a waterproof film is extremely important. But which film is best?
Which film is better for a raised bed: pond liner or studded film?
For protecting a raised bed, a thin, non-toxic pond liner is better than bubble liner because it is less expensive and serves the same purpose. Avoid PVC pond liners and choose non-toxic EPDM (rubber) liners instead.
Protecting wooden raised beds against rot
Good protection against rot is not only provided by the foil, but also by a protective coat of non-toxic paint or linseed oil.
Wood protection with foil
The pond or bubble liner is stapled or nailed to the frame of the raised bed from the inside. This will prevent the moist soil from coming into direct contact with the wood. When choosing the film, make sure that you don't necessarily choose the cheapest film. Instead, look for one without toxic ingredients and, above all, avoid plasticizers. You should also place the corner posts of the raised bed on stones so that they do not come into contact with the ground. This also allows the water to drain better and the wood to last longer.
Lazes and protective coatings
You can paint the outside of the raised bed with an environmentally friendly glaze or wood protection paint to protect it from rot and fungal attack. Such products are available both colorless and in many shades. Of course, poisonous colors have no place in a kitchen garden.
Which is better for raised beds: pond or bubble wrap?
Pond Liner is a waterproof film typically used to line an artificial garden pond. Bubble wrap is also known as drainage foil. It has studs on one side and is attached to the inside of the bed with the studded side facing outwards (i.e. towards the wood). Thanks to its structure, the film enables additional drainage by immediately draining away excess water. Basically, however, this is completely unnecessary, at least if the bed is in contact with the ground and has a thick drainage layer. A good, thin pond liner (€121.00 on Amazon) is cheaper than special bubble wrap and serves the same purpose.
Tip
It is much more important that you choose a film without toxins. PVC pond liners often contain harmful plasticizers and should therefore not be used. So-called EPDM films (rubber films) are non-toxic and do not emit any harmful substances.
