Long term use elemental sulfur to bring the pH down.

Short term treat all water with ordinary vinegar at the rate of one ounce per gallon of water (you don't have to be exact and if you used 2-3 ounces per gallon you wouldn't harm anything). This will cause the carbonates/bi-carbonates in the water to expend their acid neutralizing ability on the acetic acid in the vinegar and not be able to elevate the pH of your soil anymore. Watering with vinegar treated water also results in nutrients locked up by the high pH soil being unlocked almost as if it was lower pH soil.

So, long term=sulfur. Short term= vinegar in irrigation water.

How high is too high?

Further, where do you live?

Where are you in this world? What water was used when performing this "pH test"? What is the reason why your soils pH is supposed to be high? What is the ratio of Calcium to Magnesium?
The reasons why your soils pH arewhere they are are not addressed by those in home pH test kits, all they show you is what your soils pH might be if you do not use your tap water, or rain water, doing the test.

Yes, as Jean said, what is "too"? Follow directions on package when you purchase so you don't lower too quickly.

Dan

This is a very complex issue, and I (for one) would like a whole lot more information before I can offer any help.

What are you trying to grow, and where?

What kind of soil test kit did you use? There are some portable kits out there that I would agree are accurate, but cost a few hundred bucks. Convince us that yours is a good one. We would ALL benefit from that information.

Wow, tough crowd today.

Although, being in a similar position as the OP, I am interested to know the answers to these questions. I, also, have preformed some home test kit soil tests and found that they only reinforce what is generally known about the local soil. Though, I am sure, since everything is in agreement, someone will claim that I could not have possibly gotten a worth while test. I'm also, am too stupid to follow the directions and use distilled water (oh, wait, I did use distilled water)! The chemicals were probably too old to be of any use (oh, no well under use dates)! Then I must have read the results in fluorescent light tainting the reading of the color chart (oh, no, I checked it outside, inside and on the other side too)!

I know you all hate the home test kits, but they can give you some answers quickly and cheaply. Thank you JAG for answering the questions of the OP rather than questioning their ability.

Steve

If we appear to be a tough crowd it is because changing the pH of the soil over the long or short term in the context of 'Organic Lawn Care' is a tough topic. I will start by asking "Does the application of sulfur to the soil compromise the concept of organic culture?" If it does, what options are open to the organic practitioner? If it does not, why not?

shakikiti -
Read this and see if it answers some of your questions .

Here is a link that might be useful: Soil pH and the Home Landscape or Garden

pH is a measure of the free Hydrogen ions, the more you have the lower your pH will be. Just why you have a soil pH of any number is very complex because several things influence that and it is not very helpful to simply state you add sulfur to lower pH (although that is the best and most common way) or add lime Calcitic or Dolomitic) to raise the pH. How much is needed? Which kind of lime? Why is the pH where it is? An imbalance of Calcium and Magnesium is something you need to know because too much, or too little, Mg can influence the uptake of Calcium as well as what the soils pH is.

Contrary to common opinion, home test kits for reading soil pH do provide pretty accurate results - far more so than other home soil testing kits....IF you follow the directions properly and use distilled water :-)

Given your zone designation, I'm assuming you are in California, which does tend to towards alkaline soil conditions in many areas and also an alkaline water supply.....a double whammy! JaG's advice is valid, however should be tempered with the admonishment that altering the soil pH substantially or permanently may be difficult and heavily influenced as well by soil type. The effects are temporary and will need to be repeated periodically. It may be easier to garden in raised beds with imported soil that has more suitable characteristics.

Agricultural sulfur is fully approved (certified by NOP) as an organic application for a variety uses including that of a fungicide, a miticide and as a soil amendment. It is also a very necessary plant nutrient that is sometimes deficient in many soils.

I don't understand why so many of the regulars on this board question the validity of home soil test kits. I did both; send my soil to the local extension office, and buy a home test kit. The results were the same.

What's the big deal?

I used distilled water, I followed the instructions exactly, the results both showed high pH, low Phosphorus, good potash, low nitrogen.

I think the high pH of my soil might be from watering the lawn with well water. I'm going to test the pH of the water in the irrigation ditch. I'll bet it's lower than the well water.

Back to the OP, the pH being "too" high is relative. West of 100º in the U.S. means "high" pH. Is this "too" high? No. It is what we expect.

So, tough crowd? Not one iota. If you want to grow rhododendrons in CA and want to lower your pH to do so, you need to learn why this is a bad idea rather than going to the store and dumping sulfur in your yard.

Come now. Live with what you have and work with your environment.

Dan