Sand is a key ingredient in a classic formula for hypertufa, the material often used for casting garden planters or even faux boulders. Once hypertufa has dried, the piece you've made looks as if it were carved from stone. One basic recipe calls for equal parts sand, cement and peat moss, which results in a pot resembling limestone. As you become proficient, you can vary the proportions to create different colors and textures and even substitute perlite or vermiculite for sand. Many hypertufa creations use course sand found at home building stores.
Things You'll Need
- 2, 1-gallon plastic containers
- Dry brush
- Drop cloth
- Vegetable cooking spray
- Plastic gloves
- Face mask
- Large plastic bin
- Portland cement
- Peat moss
- Hose or water pitcher
- Plastic garbage bag or plastic sheet
Turn the pots you will be using for molds over. Scrape and wipe off any dirt or debris from the exteriors.
Spray the exteriors of the overturned pots with vegetable spray, making sure to evenly cover the sides and the bottom of the pots.
Set the pots onto a plastic bag or drop cloth.
Put 1 part sand, 1 part cement and 1 part peat moss in a plastic bin. Proportion is more important than amounts, but if you figure on about 8 cups of each material, you'll have enough hypertufa for two 1-gallon pots.
Blend the ingredients with your gloved hands until they are evenly mixed and any lumps are broken up.
Pour water in very slowly until the hypertufa is the texture of cottage cheese. Test for sufficient moisture: Squeeze a handful. It should retain its shape; if it doesn't, gradually add more water. If it is too wet, gradually mix in equal parts of the sand, cement and peat moss, until you have the right consistency.
Making the Planter
Use your hands to scoop the wet hypertufa material over the overturned pots. Aim to achieve the same thickness on all sides and on what will be the bottoms of each planter.
Press down on the bottoms of each pot so that they will have a flat surface when turned right-side up.
Poke, using your finger, at least one drainage hole in the bottom of each planter. Remove the wet hypertufa from these drainage holes.
Cover the planters with a plastic bag, and leave to harden for 24 hours.
Remove plastic sheeting and turn the planters right-side up.
Remove the pot molds from the interior of each hypertufa planter.
Make any finishing touches you desire. Pressing pebbles into the surface is one way to decorate. Roughening the surface with a dry brush creates a different look.
Leave the planters, again in plastic wrap, to cure for 48 hours.
Unwrap the planters, and leave them outside for an additional two weeks, hosing them off at least once a day to rinse away lime from the cement. If not rinsed off, the lime can leach into and add too much alkaline to the soil.
Set the planters inside a vinegar-water solution for 30 minutes to further neutralize any lime. For every 1 gallon of water needed, add 1/4 cup vinegar. After removing the planters, let them dry before filling with potting soil and seedlings.