Hypertufa is a lightweight yet strong material for homemade containers that simulates tufa rock, a popular stone for alpine garden landscapes. The substance is made with a combination of peat moss, cement and perlite. Hypertufa troughs can be easily created at home and sculpted using cardboard boxes, Styrofoam coolers or other rectangular frames. The resulting containers are perfect for planting evergreen trees for patios, decks or rooftop gardens.
Select slow-growing or dwarf varieties of evergreen plants for your containers. Smaller varieties will weigh less and create fewer stresses on decks, patios or rooftops. Because the roots of your trees will experience more temperature extremes than a tree planted in the ground, you should select trees that can handle temperature extremes.
Choose a hypertufa trough that is large enough to accommodate the root ball of the tree with a little room left over for the tree to grow. The trough should have plenty of drainage holes.
Mix a potting soil for your container that is made up of 1 part compost, 1 part peat moss, 1 part sand and 1 part moisture-retaining crystals.
Cover the drainage holes with pottery shards. Fill the container 1/3 of the way full with the potting soil.
Soak the root ball of the evergreen in a bucket of water until the roots are saturated. Rinse the root ball to gently remove the soil in the roots in a 1-inch layer. Place the root ball into the trough and fill in the space around the sides and top of the roots with dirt. Leave 1 inch of space between the soil line and the top of the container.
Check the container daily by inserting a finger into the soil up to the second knuckle joint. Water anytime the soil feels dry. The evergreen's soil should remain as damp as a wrung-out sponge.
Spread a granulated, balanced (10-10-10) fertilizer over the surface of the soil as directed by the fertilizer's package. The fertilizer instructions will vary among fertilizer varieties.