October 18, 2021

How to Make a Stone Trough

The answer to where to get a stone trough is quite simple – make your own. The process is very easy and the cost is negligible. With one bag of cement, a bag of rough sand and a couple of shovels full of peat, you can make half a dozen planters that have the look and feel of real stone. With a little special treatment, they very quickly grow algae and moss on the outside, which gives the look and feel of an ancient carved stone planter or animal drinking trough.

What you need:

  • Two cardboard boxes, the size that you want your planter to be. One must be about 2 inches smaller all around than the other one.
  • 4 wine bottle corks
  • A polystyrene fish box (get one from your local fishmonger)
  • A piece of old wire netting to act as reinforcement
  • Cement, rough concreting sand, peat and water.

These materials will give you two types of troughs, one made with the cardboard boxes and other with the polystyrene fish box. Make one of each and decide which type you prefer then produce as many as want after that.

Method one

We will start with the cardboard box method. First, you need to make your cement mixture or ‘hypertufa’. Use 1 part cement to 1 part grit and sand (concrete sand), to this add 1 part damp peat. If the peat is dry it will not blend properly with the cement mixture and cause cracks and breaks in the finished article. Mix all the ingredients together, just as you would when making ordinary cement. Make a well in the middle and add a little water. Continue mixing and adding water until you have a thick modelling type clay like paste – not a runny or sloppy cement for laying bricks.

Take the larger box and stand the 4 corks in the bottom of the box. These will act as drainage holes and also support for the other cardboard box.

This is the part where we get down and dirty. Take handfuls of your cement mixture and fill the bottom of the box up to the top of the corks and make the cement level. If you want to reinforce the cement at this stage, you can add pieces of wire netting across the base and up the sides of the box. Try to leave a small gap between the netting and the side of the box so that it does show though to the outside when turned out.

Place the second box inside the first one, sitting on the corks and cement that you have layered on the bottom. Your second box should be at least 2 inches smaller all around. This forms the mould, which will give you a trough with sides at least 2 inches thick. You need this thickness for strength. If you have used wire netting as reinforcement, then 2 inches is quite ample. 2 ½ – 3 inches is ideal.

Now it’s play time again. Keeping the inner box central, (you can place wedges in the spaces to keep the gap even all round and remove them as you proceed) press handfuls of your cement mixture down into the space between the boxes. Compact it, but don’t press too hard or you will distort the shape of the wall you are building. The boxes will be absorbing moisture from the cement so will become soft and fragile. Work quickly before the boxes become too wet. The cement will be starting to ‘go off’ and stiffen at this stage.

Work your way right around the box, building up your walls to the level that you want.

It is very important not to touch the trough for at least 24 hours. The trough is considered to be ‘green’ at this stage. What this means, is that the cement is still not cured and is in a fragile state. If you try to move it or lift it, it will crack or even break in half. Ideally, leave it alone to dry out for about 5 days, and then strip away the cardboard boxes, inside and out. You will now have a homemade stone trough.

But we are not finished yet. We need to ‘weather’ it. This is a bit like ageing a ‘new’ piece of antique furniture. Using a wire brush, roughen the surface all around the trough. Concentrate on the sharp angles of the corners and top edges to make them look worn and slightly rounded.

The final treatment is to paint the concrete with a mixture that will encourage moss and algae to form. This is the final ‘antiquing’ stage before you plant up with your alpines. The ideal medium for this is liquid manure. You can also use live yogurt or a mixture of the two. It may give off an unpleasant aroma for a short while, but this will go as the algae and moss start to develop.

Method two

This method uses the polystyrene fish box, or any other polystyrene packaging that meets your shape requirement. Trim the box to your required size and we are ready to start.

Cover the polystyrene with wire netting inside and out. Make sure that you cover the floor of the box as well. A close mesh is better for this type of mould as it not only provides reinforcement; it also allows the cement to stick to the polystyrene (which can’t absorb the liquid from the cement). Use a wooden dowel or wine corks to provide the drainage holes. Make a hole in the base of the polystyrene and place a dowel or a couple of wine corks, one on top of the other, so that they protrude about three inches above the bottom of the box. When the cement is cured we can remove the dowel or corks and leave a nice neat drainage hole.

The cement mixture is the same as in the first method. All we have to do is cover the entire box, inside and out with the mixture. Make the walls and the base at least two inches thick. (this will make the side walls nearly 4 inches thick). Use a trowel to get an even and smooth finish. Leave the tops of the walls irregular, not smooth and straight. This allows the finished product to have a more ‘rustic’ look, as though it has been hand carved.

Leave to dry and finish off as in method one.