Is it safe to use wood ash in garden soil?

Q. We have a supply of wood ashes from our fireplace that we would like to incorporate into our garden soil. Is this OK to do?A. Wood ashes from your fireplace or wood stove can be beneficial to soils in home gardens and plant beds, but they must be properly applied. Wood ash contains potassium, which can be a good natural fertilizer. However, depending on the type of wood, wood ash can contain anywhere from 3 to 10 percent potassium; hardwood ash contains more potassium than those from softwood. When water comes in contact with the wood ashes, it forms potassium hydroxide. Potassium hydroxide is highly alkaline and can rapidly raise soil pH. Before applying wood ashes, have your soil tested to determine your soil's pH. You should not apply wood ash if you have a high pH soil (greater than 6.5).When adding wood ashes, there are several guidelines you should follow:bull;After applying wood ashes, do not apply any additional lime to the soil. Like wood ash, lime increases the pH of the soil.bull;Apply ashes evenly and mix them into the soil. Don't leave ashes in lumps or piles on the soil surface. bull;Do not let wood ashes come in contact with germinating seedlings or plant roots, which could result in root damage. bull;If ashes settle on any foliage, thoroughly rinse plants after applying ashes. Ashes can cause burning of foliage. bull;Don't use wood ashes around acid-loving plants such as azaleas, rhododendrons, and blueberries.bull;Do not use charcoal grill ashes due to the chemicals used in the bonding process.Q. Are the giant tree tomato plants as good as their advertisements indicate? Can these plants be grown in Illinois successfully?#160; A. Chances are the variety being advertised is botanically known as Cyphomandra betacea, a very different species from garden tomatoes. This tree tomato is a tropical, semi-woody shrub that reaches up to 10 feet, but the fruit is more tart and jellylike than our garden tomato. People of other cultures know it as Tamarillo. It's always wise to read all the fine print in these ads since some of these ads will only send you a seed that is planted in a pot, at about $3.50 each (plus shipping).bull; Provided by Mary Boldan and Donna Siemro, University of Illinois Extension Master Gardeners. Send questions to Ask a Master Gardener, c/o Friendship Park Conservatory, 395 W. Algonquin Road, Des Plaines, IL 60016, (847) 298-3502 or via e-mail to cookcountymg@sbcglobal.net.