I second the suggestion of vinegar. I'm growing some blueberries in containers and needed to lower the pH in their pots from 6.5 to 5. I didn't need enough to buy a large bag of soil sulfur, so I added a cup of vinegar to a gallon of water. While watering the plants, I would add a few cups of the dilute vinegar. When they needed to be watered again, I tested the soil with a pH meter and added a bit more of the dilute vinegar until I had the pH down to 5. I got my meter on eBay just as DH12 said. Some people say they aren't accurate, but mine is working fine as long as I insert the probes fully into the dirt and make sure the dirt is moist. Some people don't read the instructions that say these meters won't work in liquid, and then say these cheap meters don't work. I have an aquarium test kit and and tested the pH before I got the meter, but it was difficult sometimes because water raised the readings unless I used distilled water to mix with the soil sample. The meter is quick, cheap, easy, and gave me the same results as a reagent test kit. Because of having to water frequently this summer with hard tap water, the pH creped back up to 5.5 after a month, so I added a bit more vinegar, and the pH is holding now. Greg

My Annabelle and other hydrangeas tolerate my alkaline soil, about a 7.6 ish reading (un-amended) but the soil is amended at least once in Spring... sometimes again by July-August. The problem is that the leaves begin to have trouble absorbing iron and develop iron chlorosis in late Summer; the rest of the year, the leaves are fine. I generally apply whatever amendment I have handy this time of the year and re-apply again in the Summer (if I remember or notice leaf problems). Since my purpose is not to change the color but rather to bring the soil pH down (my soil has adequate amounts of aluminum), I tend to apply soil Sulphur most of the time. So I bring the soil pH down but not that much; it is still alkaline but the hydrangeas' leaves tolerate it and stay green; they only show signs of iron chlorosis by the end of Summer and only on some years. I have also used green sand, aluminum sulfate and iron sulfate as amendments. You best start by determining what is your soil pH. And then proceed to lower the levels if they are too high. A soil test will be very useful. A soil pH kit may help some but they do not give you numeric readings so it is difficult to compare the results from one month to another month if you cannot remember how green or how pink the color was a month ago. If you can find a kit that gives numeric readings, although more expensive, it may help you control things better. You will have to continue amending the soil regularly. If you stop, the soil pH will go back to normal. So be ready to amend every month or two/three months per soil test recommendations. The soil test analysis should include recomendations on what to apply to lower the pH. When you request it, please indicate that you have hydrangeas and would like to know how often to amend the soil in order to get the soil pH to whatever level you want (say 7.0 which is neutral).

Len - I have just looked at your site and I lOVE IT! I have added it to my favourites and I am going to refer to it for my vegie patch. I thought I might tell you of my weed killing solution for pavers: I tip the left over hot boiled water everytime I make myself a tea - on weeds growing in my paving.....absolutely organic - and kills EVERYTHING! :))

See if you can find Soil & Water dudes to talk to instead of Cooperative Extension. How old is the construction? If it is more than 5 years old, then alkaline leaching has already occurred, and you've got what you've got. My personal experience, living in a lime pocket among an assortment of lime pockets, is that most gardeners have been quite thoroughly brainwashed into thinking anything in the east has to be acidic. It just isn't so. So when confronted with an alternate reality, they come up with excuses. Concrete leaching is a classic. Older concrete doesn't leach, and the leaching doesn't travel much. I don't know how many times I've been told that I should stop liming, and then I will have 'normal' acidic soil. If you want to know how the neighbor grows camellias, go over and ask. And no, my soil doesn't fizz either, and my pH, and calcium numbers are very similar to yours.