Q: I want to grow blueberries in my garden. I had the soil tested, and the results show the soil has a high pH, which is not good for growing blueberries. I have been told that I can add an acid to the soil to lower the pH, but I am afraid to try that. Do you have any suggestions? By the way, I don't understand what pH is.

A: Let's tackle the last part first. Chemists use the shorthand notation "pH" when they are looking at the acidity of a solution. The letter H stands for hydrogen.

Water molecules can split to form positively charged H+ cations and negatively charged OH- anions. The pH scale is a mathematical representation of how many hydrogen H+ cations exist. In your case, it's how many are in the soil. The scale runs from 1 to 14, and it is logarithmic rather than arithmetic, which means that each unit on the scale represents a tenfold increase (or decrease) in hydrogen ion concentration. A one-unit change is a 10X change; a two-unit change is a 100X change; a three-unit change is 1,000X. A pH of 7 is considered neutral and has equal H+ cations and hydroxide OH- anions. A pH below 7 is considered acidic and has more H+ cations. A pH above 7 is considered basic (not alkaline) and has more OH- anions.

Many people refer to a pH above 7 as alkaline, but they are wrong. Alkalinity measures the capacity to neutralize acid and is not related to the pH scale.

Enough with the chemistry lesson. Let's grow some blueberries. As the pH of a soil goes up or down, the availability of nutrients also changes. In acidic soils, some chemicals become more available; in basic soils, other chemicals become more available.

Many plants have a preferred pH range in which the nutrients they need are available. For most blueberries, the preferred pH is between 4 and 5. When the pH is that acidic, they can get the iron they need. When the soil pH goes up, they have a harder time getting iron, so their leaves turn yellow and they won't produce many berries.

Your soil test results should list the soil's current pH and how much of a specific product is necessary to get the pH in to the proper range for blueberries. Several products available at garden centers will lower soil pH. They include elemental sulfur, aluminum sulfate, iron sulfate and sulfur-coated urea. Each material has its advantages and disadvantages. You will need to follow the label directions so you don't damage the soil or the plants. Elemental sulfur lowers the pH the most without the complications of adding other chemicals to the soil. Unfortunately, it takes the longest to make any changes, as it needs to be converted into sulfuric acid by bacteria that only grow in warm soil.

Instead of trying to change the pH of your existing soil, which will require constant monitoring and additional products to prevent the pH from reverting back to the higher levels, you could replace the soil.

Blueberries can be planted into large containers, such as half wine barrels buried in the ground. They can be grown in raised beds. Some of the newer small blueberry varieties can be grown in large flowerpots. All of these containers can be filled with 50 to 100 percent peat moss. An acidic potting soil suitable for azaleas or rhododendrons makes up the rest of the mix.

This solution is simpler for you and better for the plants. You should also have your water tested, as a water source with a high pH can raise the soil pH. If your water has a high pH, you will be better off replacing the soil around the blueberries than trying to lower the pH of the existing soil.

Email questions to Jeff Rugg at info@greenerview.com. To find out more about Jeff Rugg and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.