If the leaves are pale green, or if they are looking yellow, the most likely cause is high soil pH. The least expensive method I have found for checking soil pH is bromocresol green dye indicator. You dig up a small soil sample, about one tablespoon, and mix it with distilled or de-ionized water to make a slurry. The slurry is then filtered though a paper filter, and when you have accumulated about 1/8 teaspoon of filtrate, you then add a few drops of dye. The solution will turn blue, at pH = 5.4, yellow at pH = 3.8, and varying shades of green if the pH is between 3.8 and 5.4.

ERic
where do I get this bromocresol ??? so otherwise if leaves look fine then all is prob okay???
Thanks
Jean

Bromocresol green indicator solution can be had online from HMS Beagle, a science supply house located near Kansas City, Missouri. I am sure there are other sources-the local high school chemistry teacher might know where to find it locally. One fluid ounce sells for around two dollars, and that will last for about 100 soil tests.

A neighbors told me that I could use ash from his wood stove. He thought ash would increase soil acidity. I used it when I planted my blueberry plants last year.

Is he correct?

No. Ash is alkaline, not acidic!

Wood ash will raise soil pH, not lower it. Generally, agricultural sulfur is used for lowering soil pH. Sulfur is not an acid, it must be consumed by bacteria living in the soil. The bacteria metabolize the sulfur, and eventually sulfuric acid is the result.