In recent years, raised beds made of metal have become increasingly popular. They offer a number of advantages over other types of raised beds, but they also have some disadvantages. In this post, we’ll take a closer look at the pros and cons of metal raised beds so you can decide if a metal raised bed is right for you. We’ll also go over an alternative that might be better suited for your needs.
The basics in a nutshell
When searching for metal raised beds, you’ll come across hundreds of offers on the internet. After wood and plastic, metal is the most commonly used material for raised beds. The products are available in various designs and sizes.
Metal raised beds is a generic term that combines several completely different products. These include, for example, raised beds made of sheet steel, aluminum, corten steel and stainless steel. The products are raised beds for gardening and models for terraces, interiors or balconies.
You can buy a small metal raised bed with barely 60 liters capacity for less than 50 euros, while a large raised bed made of corten steel costs well over 800 euros. For an average product you should plan up to about 200 euros. In addition to the material, it is primarily the size of the raised bed that determines the price.
Metal raised beds: What variants are available?
The products are classified by purpose and material.
Raised beds for the garden
These products are raised beds in the strict sense. They consist of several side walls, which are connected together and placed on the garden bed or soil.
There is no bottom, only a protective grid against voles. The raised bed is filled with the planting substrate and planted.
Raised beds for balconies & terraces
These products are basically planters that stand on feet, so you don’t have to bend down to take care of them. The box has no connection to the subsoil or soil. As a result, such a raised bed can be placed practically anywhere.
Metal is a collective term for various materials. For raised beds made of metal is used:
- Sheet steel
- Corten steel
- Stainless steel
- Sheet steel
This material is often used for raised beds because it is inexpensive and very durable. However, unprotected steel is susceptible to rust. Therefore, either galvanized or powder-coated steel sheet is used for raised beds. The protective coating lasts for many years.
This material is also called stainless steel. Corten steel is a special steel developed for outdoor use. It also rusts, but the rust adheres firmly to the surface and forms a coating that protects the steel underneath. The name stainless comes from the decorative reddish-brown color of Corten steel.
Compared to steel, aluminum has 2 advantages. It is much lighter and does not corrode. A raised bed made of aluminum does not require additional corrosion protection. However, aluminum is not as strong as steel and also the silver color does not fit into every environment.
This material is rarely used for raised beds. Stainless steel is the name for various steel alloys that have been made resistant to corrosion by adding other metals such as vanadium or molybdenum. While stainless steel is very strong and corrosion resistant, it is also expensive.
The advantages of raised beds made of metal
- Products made of this material are easy to assemble. As a rule, raised beds are supplied either already assembled or from individual parts that are simply screwed together.
- The metal parts do not age. They do not get cracks or holes, do not become brittle and are resistant to sunlight and UV radiation.
- Metal raised beds resistant to vermin. Even the biggest vole will bite its teeth on a steel wall.
- Metal requires little maintenance. Wiping dust and dirt from time to time is enough.
- Raised beds made of this material have a long life.
The disadvantages of metal raised beds
- The appearance of raised beds made of metal does not fit into any environment. They look cool and businesslike.
- Metal raised beds are heavier than those made of wood or plastic.
- In comparison with raised beds made of wood or plastic, they are much more expensive. This is especially true of raised beds made of aluminum, stainless steel or corten steel.
- Metal conducts heat well. Raised beds made of metal heat up strongly in summer. As a result, the planting substrate heats up and the plants need more water.
- Metal can be recycled, but it requires a lot of energy to manufacture and is therefore not environmentally friendly.
Alternatives to metal raised beds
Several materials can be considered as alternatives to metal.
This material is most often used for the manufacture of raised beds. This is due to the fact that the wood used for raised beds come from sustainable forestry.
Wood is a sustainable raw material, since it is renewable and available in large quantities. It is relatively inexpensive and is easy to work with.
Wood has excellent physical properties. It is robust and insulates heat well. Its appearance is appealing.
A disadvantage is its sensitivity to moisture. In constant wetness, it quickly rots and molds. Impregnations or paints help only temporarily and are often toxic.
To prolong the life of wooden raised beds, you should provide a drain to prevent waterlogging and line the box with foil.
This material is also relatively often used as an alternative to raised beds made of metal. Plastic has the advantages of being light and strong. In relation to the volume, plastic is the lightest of all materials for raised beds.
At the same time, plastic is resistant to corrosion. A raised bed made of plastic requires little maintenance and care. Plant juices and common household chemicals can not harm it.
Of course, plastic also has disadvantages. It reacts sensitively to prolonged exposure to sunlight.
The UV component in sunlight destroys the long molecular chains that make up plastic. This makes the material brittle and fragile, and after a while it literally disintegrates into powder.
Plastic is also harmful to the environment. It is made from petroleum, a raw material that is only available in limited quantities.
Since plastic does not corrode, it decomposes slowly in nature and is difficult to recycle.
Concrete & natural stone
Looking only at mechanical strength, both materials are well suited as materials for raised beds. Concrete and natural stone are very robust and durable.
A raised bed made of them will practically last for eternity. The surface looks attractive and fits into almost any ambience.
Despite this, concrete or natural stones are rarely used for raised beds. This is due to their biggest disadvantage: the high weight.
One cubic meter of concrete can weigh up to 2,000 kg. It is similar with natural stone.
Even a small raised bed made of concrete (without planting substrate) already weighs several hundred kilograms. This is much too heavy for a normal balcony.
Raised beds made of concrete or natural stone are more suitable for the terrace or garden.