A Hypertufa trough.

19 comments

For the benefit of those folks who do not have enamel sinks to spare, this is a description of how I made a trough from hypertufa (sand, cement and peat).
We have tried various methods of making hypertufa troughs in the past, including covering polystyrene fish boxes. To our mind none of them were particularly successful. The fish box one especially, was a spectacular failure. Our hens removed the hypertufa and ate the polystyrene. We also tried making them in cardboard boxes, but it was difficult to find satisfactory ways of keeping the boxes in shape while the trough was being created and without some sort of reinforcement, the troughs themselves were not very strong.
We had a large number of the boxes used by nurseries and garden centres for carrying plants. These were no longer needed so we wondered if it was possible to cover them in hypertufa to create a reasonable size trough.

Since we wanted a fair number of troughs, we decided to make a mould in which to create the trough. This was fairly simply four pieces of wood held together with screws. The size is simple. The internal measurements are about 5 cms. greater than the external dimensions of the plant box.

This box was then lined with plastic, so that the hypertufa would not stick to the wood.

I cut away some of the base of the box to make drainage holes. As you can see, it fits nicely into the mould.

To keep the holes open when the hypertufa is put in I used a couple of pieces of wood. They also act as a guide to the depth of the base.

Now I was ready to begin. The equipment need is fairly basic. Since the ingredients are measured by volume, a container is used for accuracy. Gloves are very important. Cement is strongly alkaline and can cause serious skin problems.

The mixture I used is the fairly standard one of two parts composted bark to one part sharp sand to one part cement. I sifted the bark first to remove and large pieces.

They need to be thoroughly mixed before adding water.

The wet mix should not be too wet. In cookery terms it would be best described as ‘stiff peak’.

Before placing the plant box in the mould a 1 cm. layer of hypertufa was spread over the whole surface. Then the box was put on top and pressed down. The pieces of wood are next pressed into the holes and a 2 cms. Layer of the mixture spread roughly over the base.

This layer is then smoothed out, taking care not to dislodge the wooden plugs.

Next the mixture is forced down the sides and tamped down using a piece of wood. It is important make sure that there are no empty spaces left. The pressure forces some of the mixture through the slits in the side of the trough. The trowel and the float are used to create a clean inside. The level of the material at the top is slightly higher than the box, so that all of the box is encased in hypertufa. There is no need to be too fussy about the smoothness of the finish.

Finally the whole thing is covered with sacks. The idea is to let it dry out slowly, If it dries too quickly then the hypertufa can crack

Once dry the mould can be removed and the trough left to dry out more before moving to its final position.

To get rid of the shiny surface left from contact with the plastic and to remove any loose or unwanted pieces, a wire brush may be used to go over the surface.

The trough may then be left to further dry out. Then comes the exciting part. planting it up!

The weight is not too much so the trough may be easily moved into position, when empty. It is best to fill with compost, rocks and plants in its final resting place though.

1 May, 2012
10 likes

Comments

Annella

Saved to my favourites for future reference Owdboggy

1 May, 2012

Terratoonie

Great.. yes also now on Favs. Thank you :o)

1 May, 2012

Lincslass

I have lots of those trays so must give that a try, thankyou Owdboggy for a very clear informative blog...

1 May, 2012

Ojibway93

Yes, straight to favourites. Very helpful guide, OB.

1 May, 2012

Dawnsaunt

Excellent, thanks.

1 May, 2012

Stroller

Like it, gone on to favourites.

1 May, 2012

Franl155

this is exactly what I've been looking for! gone straight into my faves - thanks for posting it, and thanks TT for pointing me to it.

I've only ever seen the "two box" method - I have stacks of plastic boxes similar to yours and a couple of polystyrene boxes that I want to make into troughs (or at least try to), but I couldn't work out how to do the outside as one piece -it'd have to stand on something and that would either glue the box to what it was standing on or leave patches when it was lifted.

I'm going to use concrete for my first tries - my local hardware shop sells ready-mix, and the fewer steps I take while I'm learning, the fewer chances for me to get it wrong!

Thanks again!

3 May, 2012

Owdboggy

I forgot to say in the blog that the pieces of wood were from an old bed that we dismantled. The wood was covered in plastic so even if the mix got through the covering it did not really stick to the wood.

4 May, 2012

Franl155

the recipe I was very kindly sent by a GoYer was the two-box, and a bit compilicated: stick four corks on to a board, put the corks through the bottom of the box, line with chicken wire and 'tufa, put the second box in with chicken wire frame, stuff 'tufa in, either side of the chicken wire, leave 6 weeks (!), rip the boxes off, take off the board, leaving the corks in the holes, then drill them out.

I did think that mabe covering the corks in plastic would make it easier to remove, and if the plastic was 'tufa'd in, well, that would be easy to puncture (I didn't have a drill at the time).

I bought a pack of wine bottle corks from eBay, so I might as well go the cork route, but via your directions! I've got enough scrap wood tha I rescued to make the outer frame; I'll need a bottom on it, too, as I don't think I'll be able to work on the ground, but if it can be re-used ...

Is the cocnrete/'tufa only good for filling moulds? I'd like to have a go at ornaments, laying it over something rather than filling-in - not knowing how much I should mix per trough I'll probably make too much, better than not making enough!

As for drainage, would four cork-sized holes enough? I tend to worry about not putting enough drainage in pots and planters, so as a result I usually put in too much.

4 May, 2012

Owdboggy

Should be enough holes with 4 corks. I had no trouble getting the pieces of wood out, but if you are worried then give them a good coating of Petroleum jelly (Vaseline is what it is sold as in this country.).
You can make anything you choose with hyper-tufa, it is a very malleable substance, when wet. I have used it to make the rocks which I used to build up the crevices in the troughs, but I have seen it used to make quite large boulders. If you really wanted to go to town with it, you could make a hyper-tufa wall and plant in it.
I made mine on the concrete outside my workshed and the polythene sheeting was enough to stop the mixture from sticking.
Had another thunk. If you want to make rocks then the best way is to dig a hole, line it with polythene, and fill it up with the mixture.
Just added a picture of a sculpture I made with hypertufa.

4 May, 2012

Franl155

thenk you! I'll check it out immediately. x

5 May, 2012

Franl155

just found this blog again by a different route. still only thinking about having a go, but - if the blocks, corks whateve wre put into the sides, a little way up from the base, would'nt that crate a "reservoir" for the plants to draw on in hot weather?

13 Mar, 2014

Owdboggy

Not sure, it might be that you would end up with a pond in the bottom of the 'sink' and the plants roots would rot.

14 Mar, 2014

Franl155

true! I've got some of the crates shown in the pic, but I'e also got some deeper ones, was thinking of trying it on those - but then, to be any use, the roots or soil at least would hae to reach the reseroir, unless one put some kind of wick in to lead the water up to where it'd be needed. probably eaiser not to

14 Mar, 2014

Owdboggy

The trouble, as far as I can see, would be that the water in the bottom, below the drainage holes would become stagnant and that is definitely not a good thing. I am not even sure that one should put a layer of drainage material in the bottom of the trough. There is an opinion that this collects water which gets stagnant and kills the roots which come into contacts with t.

15 Mar, 2014

Franl155

ah, right. but wouldn't that apply even if soil went all the way down? the moisture at the bottom would tend to stay there, and similarly stagnate. unless one let the trough dry out completely, all the way down, before watering

15 Mar, 2014

Owdboggy

Not if there are decent drainage holes in the bottom of the trough. Water then goes through. Remember that plants need oxygen as well as water and it is the action of water passing through the soil that brings oxygen to the plants roots.
This is one reason why some plants from high mountain areas are so difficult to grow, they do not get the highly oxygenated water flowing through them.

15 Mar, 2014

Franl155

thanks, Owdbaggy - I had been thinking of troughs as closed units, rather than large square plant pots! durr.

Had been thinking about making indivudual square pots out of concrete, so that I could have all my plants at the same level but independent, so I could turn one or move them around but have pots nestled so it looked like one large unit - apart from that, each would be a lot lighter and so easier to rearrange. I'd been thinking about building in a "reservoir", but given what you've said, I'll defintely rethink that.

16 Mar, 2014