I’ve been wanting to making hypertufa pots for years. As is the case with so many things, however, I never got around to it. Until today. I finally had everything I needed—including spare time—so there was no more excuse.
There are many different recipes for hypertufa but typically it is made of Portland cement, perlite and peat moss. I used 2 gallons of Portland cement, 2 gallons of perlite, and 4 gallons of peat moss.
To make my pots extra strong, I added 1/2 cup of nylon fibers. I ordered them from Amazon, and I have a feeling the 1 lb. bag will last me a lifetime.
I spent a long time thoroughly mixing the dry ingredients. It seemed like a good idea to ensure proper bonding.
Then I added 3 gallons of water and mixed everything together. I had underestimated how long this would take. I spent a good 10 minutes at it, but again I wanted to make sure everything was mixed well.
For molds I had chosen cardboard boxes. I had plenty on hand, and I wanted rectangular shapes instead of round. I simply pressed the mixture into each box (about 2 inches at the bottom) and built the walls to be about 1 1/2 inches thick.
Outside dimensions (width x height x depth)
I didn’t line the boxes with plastic, like some people suggest. I don’t think plastic is needed, but I could be deadly wrong. But I figure even if there are bits and pieces of cardboard stuck to the side of the pots I can remove them using a wire brush. Time will tell whether my assumption is correct.
Looking at the finished pots, I think my mix had a bit too much water in it. I don’t think it’s detrimental, but the hypertufa will take longer to dry.
I wrapped the finished pots with plastic drop cloth and will now let them set. There is a great deal of divergent information on the Internet regarding this step. Some people say 24 hours, others 2 days, others a week or longer. Logically speaking this all depends on the ambient temperature and the humidity.
Considering today’s high is expected to be in the low 70s, I will check tomorrow afternoon (i.e. 30 hours later). I will then make drain holes using an apple corer and, if the hypertufa is dry enough, remove the cardboard and brush the outside with a wire brush for a more natural texture.
It will then take another 2-4 weeks for the hypertufa to fully cure. After that some people suggest waiting 1-2 months for the material to age before planting because Portland cement has a high lime context that would damage plants.
In summary, these are the materials I used:
- 2 gallons Portland cement
- 2 gallons perlite
- 4 gallons peat moss
- 1/2 cup nylon reinforcement fibers
- 3 gallons water (might have been 1/2 quart too much)
This project was lot of fun. I’ll collect more boxes and look for other molds. As I get better at this, I want to make larger troughs like this one.