Corrugated steel garden beds are getting quite popular these days, and for a good reason. The demand is there and steadily increasing, so manufacturers have stepped up and increased production where they can. The problem with some available types is that the top and bottom edges are left quite sharp. So how can we make the edges safer without spending heaps? The solution is a simple one.
Can sharp edges on metal garden beds be made safer?
Split poly piping or a similar material can be attached over the sharp edges to protect the gardener from potential injuries, making the edges safe for fingers and plant stems.
This article goes into the methods and the materials to consider. It is surprising how easy and cheap it can be. When we redesigned our backyard to fit raised garden beds, the local hardware was out of the Olle garden bed we needed.
There was an extended waiting list, so we contacted a local plumbing shop that fitted sheet metal roofing in the construction industry. This plumbing business had recently started making garden beds with spare metal.
We bought several of these, but they all came with sharp, exposed edges. They were also no match for the quality of the Olle garden beds we have since bought & added to the collection.
What are the risks of corrugated steel bed edges?
The primary risks from the edges of corrugated steel garden beds are cuts, abrasions, rust, and rusty steel-related injuries that can cause serious problems.
Another issue that can be of concern is that it can harm plants as they grow outside the boundaries of the garden bed. It can cut stems and other plant parts due to the overhanging weight resting on the sharp edges.
There are also a couple of danger issues and longevity questions with metal garden beds, and most revolve around the rusting of the walls over time. Rust can be an issue if the soil within the metal raised garden bed is too acidic. Using soil like this is probably purely accidental and likely something that originated from the soil supplier, assuming the gardener bought the soil.
Rust can also occur on the metal where it has been drilled or cut with a grinder or snips. The cutting of the sheets can be from cutting down an old water tank or something similar, as many people like to re-purpose items. Cut-down water tanks have a serious safety issue if the cut is at the top of the bed and is left unprotected.
The edges of these beds are likely to rust at the cut, leading to potential nasty injuries to the gardener. At this stage, you may wonder if these metal raised garden beds are worth it. If so, the below section “Why use corrugated steel raised garden beds?” might help. We have also listed the disadvantages of these beds in “Organic raised bed gardening, what are the disadvantages?” for you to consider before lining up to buy them.
How to cover sharp edges with minimal cost.
Because the corrugated steel beds are thin sheet metal rolled into the corrugated form, the edge we need to cover is often under 1mm.
This thinness allows for fitting a garden hose or similar to the sheet edge if the hose is sliced lengthwise in a relatively straight line. This hose is then spread apart and pushed over the cut metal edge, protecting the gardener from potential rusty iron cuts and injuries.
Garden irrigation pipe, or poly pipe, can also be used and is potentially better than the nylon garden hose because of the UV stabilizing effect that is often incorporated into the material.
A material called Carbon Black is added during manufacture and will protect the pipe from UV for many years.
How long will edge protection last on a garden bed?
Longevity will depend on the edge covering tube you use. Nylon garden hoses of poor quality will not last as long as PE pipe.
The industry claims that UV stabilized PE pipe will last 50-80 years long. The only causes of your poly pipe deteriorating should be from strong acids and hydrocarbons like diesel and fuel oils. Otherwise, the tube should not rust, rot, or react with your garden bed sheet.
The best solution we have found using this pipe is the thin-walled, low-pressure irrigation line that is 3/4 inch in diameter (19mm). It cuts easily along its length and wraps around the curved ends of the raised garden beds easily. The pipe has enough spring to hold it onto the garden bed edges without additional fasteners. It may pop off when the sun is scorching hot and if the plastic softens.
Suppose your raised metal garden bed has cut edges; it might be a good idea to paint these edges before fitting the pipe. The paint can help counter rust issues that remain hidden under the tube.
Why use corrugated raised garden beds
Raised garden beds are helpful for the following purposes.
- Gardening with raised garden beds can be easier on your back.
- Raised garden beds allow you to control the soil conditions and pests.
- The garden beds are light and self-supporting. Some beds require a belly bolt to keep the sides from bulging out.
- Some brands of raised beds have a range of colors that can look great. Shiny galvanized beds can be glary in bright sun, but can reflect heat in the summer.
Gardening while standing is very appealing for anyone with a back issue or anything related to pain when bending over. So raised metal garden beds are the best solution that many of us have found.
The raised bed allows you to control the soil condition to benefit the plants you wish to grow. Semi-permeable fabrics placed at the bottom of the garden beds can aid in moisture retention. Metal mesh can also stop burrowing critters from entering the bed from underground.
There are temperature issues near the metal sides of these beds in certain conditions, and we go into this in-depth in “Does the soil in metal raised garden beds get hot?” We highly recommend reading this one.
Alternative Methods
Some people like the look of a timber top edge. They look great and can give the gardener a seat to rest on as they do their tasks. However, the problem with a wooden garden top edge is that they are exposed to the elements and get wet when plants are being watered.
The moisture can then cause the wood to rot, leading to additional construction work to replace the wooden tops when they start to break down. This will happen eventually; it is only a matter of time.
Some raised garden beds have quite a bit of wood in their construction, and from our perspective, any wood that is in contact with the soil is subject to possible accelerated rotting.
On the other hand, a full metal bed contains no wood in the framework and will not create that issue.
Conclusions
Sharp edges can and should be safely covered to also protect the little fingers of children when they play in the garden. In consideration of these risks, metal raised garden beds are a fantastic choice. They have a decent life span and are simple to assembly. Garden beds kits from manufacturers like Olle (from the USA) can be constructed into several different shapes through their modular design to fit your yard.
These beds come with a plastic clip-over edge protector strip that serves the purpose of protecting oneself from the sharp metal edges. Although you can try to make your own DIY cover edge protector, it can be pretty expensive to create a similar quality edge protector separately.
