Truffles are small, white and bumpy mushroom-like delicacies that grow in soil around certain trees. Truffles are known as a special type of fungus and can usually be found growing wild in the forest, where people forage for them. Truffles can only grow in a symbiotic relationship with roots of specific trees--they can never grow alone. When growing truffles in a greenhouse, it is important to have enough space and the patience to wait for truffles to grow. Although it takes time for the first truffle crop to grow, after that the trees can produce truffles for many years.
Choose a growing site to start the "truffle orchard." You will need a large greenhouse with southern exposure that provides plenty of room and sunlight.
Prepare the greenhouse soil. You want straight good quality potting soil with no debris. Mix a compost foundation and lime into the top 12 inches of the soil.
Purchase and bring to the greenhouse oak trees injected with truffle fungus from an approved truffle grower.
Dig holes into the soil that are twice as wide as the oak trees' roots and at least 2 to 3 feet deep. Keep the hole about 20 feet apart. Plant the trees into the holes, spreading out the roots. Back fill the holes with soil and pack it down with your hands. Plant as many oak trees as possible for the optimum amount of truffles.
Water the oak tree orchard thoroughly after planting. Maintain the moisture throughout the year so the soil is consistently moist for truffle growth. Use an irrigation system if possible for the easiest maintenance.
Layer mulch such as grass clippings or wood chips under the oak trees to provide an ideal environment for truffle growth.
Wait about a year and check the soil, carefully moving your fingers around in the top couple inches of the soil. Look for small, rounded lumps around the roots. These are the truffles. Harvest them by carefully plucking them from the roots and washing thoroughly before using.