Tufa is a variety of limestone that is found around the world. It is porous and soft enough to carve, used in building and to make various other things such as livestock water troughs. It eventually was used by gardeners to plant in. Because of its porous properties, it was used for herb and succulent plantings. Eventually to mimic the natural tufa stone a concrete mixture called hypertufa was used to make planters. We have made many different types of containers, troughs, bowls and almost any shape you can come up with a mold for. We have found that herbs and succulents do quite well because of the porous nature but don’t’ limit yourself to these. Other flowers thrive in them too.
Following are the ingredients and steps that we have always used to make our containers.
1 part portland cement (pure portland cement, nothing that says mix on the bag)
1 part peat moss
1 part perlite or you can substitute vermiculite for a smoother finish
Approximately 1 part water (This will vary. Will talk more about water in the instructions)
Optional: Liquid Concrete bonding agent added to the water. (Approximately 1 ounce per gallon)
Oil Spray to spray your form
Plastic trash bag large enough to accomodate your container
Dust mask (All of these materials are very dusty and can cause irritation to your lungs)
Heavy Rubber Gloves that extend above the wrist (Cement can cause skin irritation)
Container for mixing the ingredients
Form to shape your hypertufa on (Can be bowl, trough, or just about anything else. A smooth surface works best for removing it from the form)
If your form is more of a rough surface you may want to line it with plastic to help it to release easier.
Instructions for making the hypertufa:
Find a firm surface to work on
Put on your mask and gloves
Put equal parts of your peat moss, portland cement and perlite into your mixing container. Peat moss is sometimes compressed so make sure that it is broken apart and fine, no lumpy pieces before adding it to your other ingredients.
Mix the 3 dry ingredients together thoroughly in your mixing container.
Make a well and start adding water slowly and working it into the mix with your hands. You want to wet it enough so that the mixture ends up being the consistency of cottage cheese. Slowly add more water as you see that you need it. You want to ball up the mixture in your hands and when you squeeze it very little water comes out. If it gets too wet you can always add equal parts of the dry mixture back to the mix. In this step it is much easier to add a little bit of water at a time to keep from getting it too wet.
Once you have it mixed and ready to form spray your mold where the mixture will come into contact with it. This will make it release much easier.
A simple plastic mixing bowl is an easy way to get started.
Start forming the cement mix on the inside bottom of the bowl, 1 1/2 – 2″ thick is a good thickness. Using a toothpick to stick in gives you a good indicator of the thickness as you are working.
After you have the bottom start working your way up the sides leaving the void in the center for your planting. Always pack the mixture firmly to remove any air pockets.
Make a drainage hole in the bottom using either your finger or a dowel rod. We find the finger is always handiest.
After the mixture is formed slide it into a plastic bag (leaving it in the mold) and let cure in a shady area for 2-3 days.
After the third day you are ready to remove your planter from the mold.
Gently turn it upside down and begin to separate the hypertufa container from your mold.
At this time you can use a wire brush to smooth off rough edges or do any scraping or sculpting that you want to do.
After you have the finish that you want you can place it back in the plastic bag and let it cure for another 2-3 weeks.
Your hypertufa pot is very alkaline and to make it more plant friendly you can give it a vinegar wash. Stuff your drainage hole with a cloth or plastic to hold the water in for a little while, 30 minutes to an hour will be good. Mix 1 part vinegar and 9 parts water and pour into the container. Let this sit and soak in. After about 30 minutes to an hour go ahead and rinse out any that is left in the bowl. Flush it several times with plain water.
Now your hypertufa pot is ready to plant.