How to Grow Truffles in the U.S.

Obtain host trees. These specialty trees are inoculated with truffle fungus, usually of the Tuber melanosporum variety. Tree varieties include oak, hazelnut and others. A handful of American truffieres and truffle cultivation specialists offer host trees for order online since these specialty trees are not available in stores. As of 2011, inoculated trees retail for about $25 to $75 each. You'll need roughly 500 trees per acre to start a successful orchard, according to the truffiere at Garland Truffles.

Select a location with mild temperatures and a climate free of extreme summer heat or winter cold. Avoid locations that have frozen soil during the winter season. In the U.S., the southeast, mid-Atlantic region and West Coast -- including areas of California, Oregon and Washington -- provide suitable climates, as do areas of Texas, Oklahoma and Idaho. The Carolinas, Tennessee and Virginia have yielded successful truffle harvests, as well.

Choose a planting site with extremely well-drained soil. Truffles grow in most soil types, including sandy loam, clay loam and rocky soil. Pick soil with a pH level of around 8, as the plants thrive in acidic soils. Test the soil for nutrient deficiencies; truffles prefer soil high in nutrients. Your local U.S. Department of Agriculture Cooperative Extension may be able to help test the soil and correct imbalances. It may be necessary to amend the soil with lime.

Remove ectomycorrhizal trees, such as conifers, oaks, nut trees and certain types of shrubs, from the planting site. In some cases, these trees host root fungi that compete with truffles. Make the site's soil as root-free as possible before planting host trees.

Plant your truffle host trees on sunny slopes with slants of up to 15 degrees, preferably facing south or west. Plant the trees with 6 feet between each tree and 12 feet between rows.

Irrigate the trees with clean water, keeping them moist throughout the year. Aerate the soil regularly; never allow standing water. Use mulch around the trees to keep the surrounding soil suitably moist.

Allow several years for truffles to appear underground. If your truffle orchard is successful, growth may appear in about five years. Use a trained truffle dog or pig to detect mature truffles, and dig them up by hand. Carefully replace the soil once the truffles have been harvested.