Hypertufa--the term given to mixtures of Portland cement, peat moss and perlite or vermiculite--mimics real volcanic stone, serving as a creative medium you can use to produce attractive garden pots and planters.
Put on the rubber gloves, glasses and face mask. Open your ingredients and inspect them. The Portland cement should be fresh and not caked by water damage. Fluff the peat moss by hand as much as possible.
Mix together one part Portland cement, one part peat moss and one part perlite in a wheelbarrow or container.
Add water slowly and stir the ingredients together by hand until the mixture reaches the consistency of thick mud. If you accidentally add too much water, add a small amount of each dry ingredient to take up the extra liquid.
Spread petroleum jelly on the outside of the plastic flowerpot or bowl and place the bowl or pot upside down on a work table.
Scoop the hypertufa by hand and press it onto the outside of the mould. Continue adding and pressing the hypertufa mixture onto the mould until it is between 3/4 inch and 1 inch thick, completely covering the mould.
Wrap the flower pot with plastic sheeting and place it in a protected area for curing. Immediately use any remaining hypertufa mix for another project or discard it.
Remove the plastic sheeting from your flowerpot after 24 hours. Gently pry the plastic mould from inside the hypertufa pot and remove it.
Brush the outside of your hypertufa pot with the wire brush to give it a more authentic aged look.
Place the hypertufa flowerpot in a protected area to cure for at least two to three weeks.
Soak the pot in water after the curing is complete to remove lime remaining from the cement. Let the pot dry before planting flowers or shrubs in it.
Experiment with different mould sizes and shapes for your hypertufa designs.
Handle the hypertufa pot gently when brushing it with the wire brush, as it has not finished curing. Dust from the cement, moss and perlite can be dangerous, and lime in Portland cement can cause burns on your skin. Always wear safety glasses, a face mask and gloves when working with these ingredients.